BMC Ecology

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Distribution of Papio species and location of samples analyzed. Ychr.: Y chromosome sequence data; mtDNA: mitochondrial DNA genome. Shapes refer to the inset legend. Samples whose original place of origin is unknown are enclosed in a dashed box. Color scheme of Papio species distribution is as follows: P. papio = red, P. anubis = green, P. kindae = orange, P. cynocephalus = yellow, P. ursinus = brown, and GNP= blue. (Information on sample provenance collected from Additional file 2: Table S3 in Rogers et al. [11], Table 1 in Zinner et al. [10] and Appendix S1 in Wall et al. [15])
GNP baboon genomic variation and Papio diversity. A Phylogeny of Papio mitogenomes using Theropithecus gelada as an outgroup; codes refer to the specimen identifiers used in Zinner et al. [10]. GNP: baboon sample collected in Gorongosa National Park (code: bf146); colors indicate the different species listed in the legend. All nodes have a posterior probability of 1. Divergence times are reported (confidence intervals shown as gray boxes; values in Tables S2). B Y chromosome Papio phylogeny based on six concatenated genes (see main text); codes as in Additional file 2: Table S1; Hap refers to a P. cynocephalus male sample from Wall et al. [15]; colors refer to legend in panel A. All nodes have a posterior probability of 1. Divergence times are reported (confidence intervals shown as gray boxes; values in Tables S3). Macaca mulatta was used as an outgroup. C Heterozygosity estimates across Papio; colors as legend in panel A; sample codes as reported in Additional file 2: Table S1. D Principal component analysis (PCA) of Papio autosomal genomic data; codes and colors as in panel legend in panel A
Genomic history of GNP and other baboons. A Patterns of shared alleles (D-statistics results). Upper panel: P. ursinus and GNP comparisons; lower panel: P. anubis and P. anubis 30877 comparisons. H1 and H2 refer to the two populations being compared to the test population, H3. Bars show the extension of three standard deviations; thicker parts refer to a single standard deviation. Colors as in Fig. 2. B Reconstruction of the genetic relationships between different Papio species with the addition of admixture events using qpGraph. GNP and all Papio species, except for P. kindae and P. hamadryas, are included. The f 4 statistics (Z = 1.356) with poorest correlation, reported at the top, do not reject the topology in the figure. The label "Mozambique" refers to sample GNP. C Changes in effective population sizes. The results of the PSMC analysis for GNP and one individual for each Papio species, including all sites. Full results in Additional file 1: Fig. S5
Background Gorongosa National Park in Mozambique hosts a large population of baboons, numbering over 200 troops. Gorongosa baboons have been tentatively identified as part of Papio ursinus on the basis of previous limited morphological analysis and a handful of mitochondrial DNA sequences. However, a recent morphological and morphometric analysis of Gorongosa baboons pinpointed the occurrence of several traits intermediate between P. ursinus and P. cynocephalus , leaving open the possibility of past and/or ongoing gene flow in the baboon population of Gorongosa National Park. In order to investigate the evolutionary history of baboons in Gorongosa, we generated high and low coverage whole genome sequence data of Gorongosa baboons and compared it to available Papio genomes. Results We confirmed that P. ursinus is the species closest to Gorongosa baboons. However, the Gorongosa baboon genomes share more derived alleles with P. cynocephalus than P. ursinus does, but no recent gene flow between P. ursinus and P. cynocephalus was detected when available Papio genomes were analyzed. Our results, based on the analysis of autosomal, mitochondrial and Y chromosome data, suggest complex, possibly male-biased, gene flow between Gorongosa baboons and P. cynocephalus , hinting to direct or indirect contributions from baboons belonging to the “northern” Papio clade, and signal the presence of population structure within P. ursinus . Conclusions The analysis of genome data generated from baboon samples collected in central Mozambique highlighted a complex set of evolutionary relationships with other baboons. Our results provided new insights in the population dynamics that have shaped baboon diversity.
Through a meta-analysis, Mupepele et al. (BMC Ecol Evol 21:1-193, 2021) assessed the effects of European agro-forestry systems on biodiversity, estimated by species richness or species diversity. They showed that the effects of silvoarable and silvopastoral systems depend on the systems they are compared to and the taxa studied. Further, they found that only silvoarable systems increased species richness or diversity, compared to cropland. The authors conclude that agroforestry systems have weak effects on biodiversity and that landscape context or land-use history are probably more important than the practice of agroforestry in itself. However, we draw attention to important shortcomings in this meta-analysis, which downplay the potential of agroforestry for biodiversity conservation in agricultural landscapes. We hope that the meta-analysis by Mupepele et al. (BMC Ecol Evol 21:1-193, 2021), and our comments, will contribute to improving the quality of research on agroforestry systems and biodiversity conservation.
Larvae to adults survival (Experiment 3.3). Selection, treatment, or selection × treatment did not significantly affect mean larvae to adults survival. The light gray box plot represents the FCB, and the dark gray box plot represents the FSB populations
Larvae to adults survival (Experiment 3.3)
Background In insect species like Drosophila melanogaster , evolution of increased resistance or evolution of particular traits under specific environmental conditions can lead to energy trade-offs with other crucial life-history traits. Adaptation to cold stress can, in principle, involve modification of reproductive traits and physiological responses. Reproductive traits carry a substantial cost; and therefore, the evolution of reproductive traits in response to cold stress could potentially lead to trade-offs with other life-history traits. We have successfully selected replicate populations of Drosophila melanogaster for increased resistance to cold shock for over 33 generations. In these populations, the ability to recover from cold shock, mate, and lay fertile eggs 24 h post cold shock is under selection. These populations have evolved a suite of reproductive traits including increased egg viability, male mating ability, and siring ability post cold shock. These populations also show elevated mating rate both with and without cold shock. In the present study, we quantified a suite of life-history related traits in these populations to assess if evolution of cold shock resistance in these populations comes at a cost of other life-history traits. Results To assess life-history cost, we measured egg viability, mating frequency, longevity, lifetime fecundity, adult mortality, larva to adult development time, larvae to adults survival, and body weight in the cold shock selected populations and their controls under two treatments (a) post cold chock and (b) without cold shock. Twenty-four hours post cold shock, the selected population had significantly higher egg viability and mating frequency compared to control populations indicating that they have higher cold shock resistance. Selected populations had significantly longer pre-adult development time compared to their control populations. Females from the selected populations had higher body weight compared to their control populations. However, we did not find any significant difference between the selected and control populations in longevity, lifetime fecundity, adult mortality, larvae to adults survival, and male body weight under the cold chock or no cold shock treatments. Conclusions These findings suggest that cold shock selected populations have evolved higher mating frequency and egg viability. However, there is no apparent life-history associated cost with the evolution of egg viability and reproductive performances under the cold stress condition.
Background Sri Lanka is a continental island separated from India by the Palk Strait, a shallow-shelf sea, which was emergent during periods of lowered sea level. Its biodiversity is concentrated in its perhumid south-western ‘wet zone’. The island’s freshwater fishes are dominated by the Cyprinidae, characterized by small diversifications of species derived from dispersals from India. These include five diminutive, endemic species of Pethia ( P. bandula , P. cumingii , P. melanomaculata , P. nigrofasciata , P. reval ), whose evolutionary history remains poorly understood. Here, based on comprehensive geographic sampling, we explore the phylogeny, phylogeography and morphological diversity of the genus in Sri Lanka. Results The phylogenetic analyses, based on mitochondrial and nuclear loci, recover Sri Lankan Pethia as polyphyletic. The reciprocal monophyly of P. bandula and P. nigrofasciata , and P. cumingii and P. reval , is not supported. Pethia nigrofasciata , P. cumingii , and P. reval show strong phylogeographic structure in the wet zone, compared with P. melanomaculata , which ranges across the dry and intermediate zones. Translocated populations of P. nigrofasciata and P. reval in the Central Hills likely originate from multiple sources. Morphological analyses reveal populations of P. nigrofasciata proximal to P. bandula , a narrow-range endemic, to have a mix of characters between the two species. Similarly, populations of P. cumingii in the Kalu basin possess orange fins, a state between the red-finned P. reval from Kelani to Deduru and yellow-finned P. cumingii from Bentara to Gin basins. Conclusions Polyphyly in Sri Lankan Pethia suggests two or three colonizations from mainland India. Strong phylogeographic structure in P. nigrofasciata , P. cumingii and P. reval , compared with P. melanomaculata , supports a model wherein the topographically complex wet zone harbors greater genetic diversity than the topographically uniform dry-zone. Mixed morphological characters between P. bandula and P. nigrofasciata , and P. cumingii and P. reval , and their unresolved phylogenies, may suggest recent speciation scenarios with incomplete lineage sorting, or hybridization.
Background Alligator lizards (Gerrhonotinae) are a well-known group of extant North American lizard. Although many fossils were previously referred to Gerrhonotinae, most of those fossils are isolated and fragmentary cranial elements that could not be placed in a precise phylogenetic context, and only a handful of known fossils are articulated skulls. The fossil record has provided limited information on the biogeography and phylogeny of Gerrhonotinae. Results We redescribe a nearly complete articulated fossil skull from the Pliocene sediments of the Anza-Borrego Desert in southern California, and refer the specimen to the alligator lizard genus Elgaria . The fossil is a representative of a newly described species, Elgaria peludoverde . We created a morphological matrix to assess the phylogeny of alligator lizards and facilitate identifications of fossil gerrhonotines. The matrix contains a considerably expanded taxonomic sample relative to previous morphological studies of gerrhonotines, and we sampled two specimens for many species to partially account for intraspecific variation. Specimen-based phylogenetic analyses of our dataset using Bayesian inference and parsimony inferred that Elgaria peludoverde is part of crown Elgaria . The new species is potentially related to the extant species Elgaria kingii and Elgaria paucicarinata , but that relationship was not strongly supported, probably because of extensive variation among Elgaria . We explored several alternative biogeographic scenarios implied by the geographic and temporal occurrence of the new species and its potential phylogenetic placements. Conclusions Elgaria peludoverde is the first described extinct species of Elgaria and provides new information on the biogeographic history and diversification of Elgaria . Our research expands the understanding of phylogenetic relationships and biogeography of alligator lizards and strengthens the foundation of future investigations. The osteological data and phylogenetic matrix that we provided will be critical for future efforts to place fossil gerrhonotines. Despite limited intraspecific sampled sizes, we encountered substantial variation among gerrhonotines, demonstrating the value of exploring patterns of variation for morphological phylogenetics and for the phylogenetic placement of fossils. Future osteological investigations on the species we examined and on species we did not examine will continue to augment our knowledge of patterns of variation in alligator lizards and aid in phylogenetics and fossil placement.
Relationships of community above-and belowground biomass with soil factors across four years in the desert steppe. Only significant (p ≤ 0.05) relationships were shown
Structural equation modeling (SEM) depicting the effect paths of extreme drought treatments, precipitation in the early growing season (March to June), functional trait and soil properties on above-and belowground biomass. Square boxes indicate variables included in the model. Single headed arrows indicate paths. Numbers on path is the standardized regression weights. Total explained variance (R2) of biomass is on the right corner of boxes. Using the *, ** and*** to show the significance along the paths at the level of P < 0.05, P < 0.01and P < 0.001. Results of model fitting: χ 2 =16.936, P = 0.110, RMSEA = 0.087, GFI = 0.943
Abbreviations AGB: Aboveground biomass; BGB: Belowground biomass; CWM: Communityweighted means; SLA: Specific leaf area; LDMC: Leaf dry matter content; LCC: Leaf carbon content; LNC: Leaf nitrogen content; Soil N: Soil nitrogen content.
Background Increasing drought induced by global climate changes is altering the structure and function of grassland ecosystems. However, there is a lack of understanding of how drought affects the trade-off of above- and belowground biomass in desert steppe. We conducted a four-year (2015–2018) drought experiment to examine the responses of community above-and belowground biomass (AGB and BGB) to manipulated drought and natural drought in the early period of growing season (from March to June) in a desert steppe. We compared the associations of drought with species diversity (species richness and density), community-weighted means (CWM) of five traits, and soil factors (soil Water, soil carbon content, and soil nitrogen content) for grass communities. Meanwhile, we used the structural equation modeling (SEM) to elucidate whether drought affects AGB and BGB by altering species diversity, functional traits, or soil factors. Results We found that manipulated drought affected soil water content, but not on soil carbon and nitrogen content. Experimental drought reduced the species richness, and species modified the CWM of traits to cope with a natural drought of an early time in the growing season. We also found that the experimental and natural drought decreased AGB, while natural drought increased BGB. AGB was positively correlated with species richness, density, CWM of plant height, and soil water. BGB was negatively correlated with CWM of plant height, CWM of leaf dry matter content, and soil nitrogen content, while was positively correlated with CWM of specific leaf area, CWM of leaf nitrogen content, soil water, and soil carbon content. The SEM results indicated that the experimental and natural drought indirectly decreased AGB by reducing species richness and plant height, while natural drought and soil nitrogen content directly affected BGB. Conclusions These results suggest that species richness and functional traits can modulate the effects of drought on AGB, however natural drought and soil nitrogen determine BGB. Our findings demonstrate that the long-term observation and experiment are necessary to understand the underlying mechanism of the allocation and trade-off of community above-and belowground biomass.
A contour plot visualizing the interaction between population allelic richness and AMF richness of S. pratensis. The relative population growth is represented by the contour curves. No significant interaction between population allelic richness and AMF richness was found
Venn diagram representing variance partitioning results of AMF communities among three explanatory matrices, i.e. geography, soil and allelic composition of S. pratensis. The size of the circles is proportional to the variability in AMF communities as explained by a particular explanatory matrix, while overlap of the circles represents the shared variation among explanatory matrices. Numbers indicate the adjusted R 2 values and thus the variability explained by each partition
Background: Ecosystem restoration is as a critical tool to counteract the decline of biodiversity and recover vital ecosystem services. Restoration efforts, however, often fall short of meeting their goals. Although functionally important levels of biodiversity can significantly contribute to the outcome of ecosystem restoration, they are often overlooked. One such important facet of biodiversity is within-species genetic diversity, which is fundamental to population fitness and adaptation to environmental change. Also the diversity of arbuscular mycorrhizal fungi (AMF), obligate root symbionts that regulate nutrient and carbon cycles, potentially plays a vital role in mediating ecosystem restoration outcome. In this study, we investigated the relative contribution of intraspecific population genetic diversity, AMF diversity, and their interaction, to population recovery of Succisa pratensis, a key species of nutrient poor semi natural grasslands. We genotyped 180 individuals from 12 populations of S. pratensis and characterized AMF composition in their roots, using microsatellite markers and next generation amplicon sequencing, respectively. We also investigated whether the genetic makeup of the host plant species can structure the composition of root-inhabiting AMF communities. Results: Our analysis revealed that population allelic richness was strongly positively correlated to relative population growth, whereas AMF richness and its interaction with population genetic diversity did not significantly contribute. The variation partitioning analysis showed that, after accounting for soil and spatial variables, the plant genetic makeup explained a small but significant part of the unique variation in AMF communities. Conclusions: Our results confirm that population genetic diversity can contribute to population recovery, highlighting the importance of within-species genetic diversity for the success of restoration. We could not find evidence, however, that population recovery benefits from the presence of more diverse AMF communities. Our analysis also showed that the genetic makeup of the host plant structured root-inhabiting AMF communities, suggesting that the plant genetic makeup may be linked to genes that control symbiosis development.
Correction to: Climatic and topographic changes since the Miocene influenced the diversification and biogeography of the tent tortoise (Psammobates tentorius) species complex in Southern Africa
Background The earliest Miocene (Aquitanian) represents a crucial time interval in the evolution of European squamates (i.e., lizards and snakes), witnessing a high diversity of taxa, including an array of extinct forms but also representatives of extant genera. We here conduct a taxonomical survey along with a histological/microanatomical approach on new squamate remains from the earliest Miocene of Saint-Gérand-le-Puy, France, an area that has been well known for its fossil discoveries since the nineteenth century. Results We document new occurrences of taxa, among which, the lacertid Janosikia and the anguid Ophisaurus holeci , were previously unknown from France. We provide a detailed description of the anatomical structures of the various cranial and postcranial remains of lizards and snakes from Saint-Gérand-le-Puy. By applying micro-CT scanning in the most complete cranial elements of our sample, we decipher previously unknown microanatomical features. We report in detail the subsurface distribution and 3D connectivity of vascular channels in the anguid parietal. The fine meshwork of channels and cavities or sinuses in the parietal of Ophisaurus could indicate some thermoregulatory function, as it has recently been demonstrated for other vertebrate groups, providing implications for the palaeophysiology of this earliest Miocene anguine lizard. Conclusions A combination of anatomical and micro-anatomical/histological approach, aided by micro-CT scanning, enabled the documentation of these new earliest Miocene squamate remains. A distinct geographic expansion is provided for the extinct anguine Ophisaurus holeci and the lacertid Janosikia (the closest relative of the extant insular Gallotia from the Canary Islands).
Background Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) is among the economically most important freshwater fish species in East Africa, and a major source of protein for local consumption. Human induced translocations of non-native stocks for aquaculture and fisheries have been found as a potential threat to the genetic diversity and integrity of local populations. In the present study, we investigate the genetic structure of O. niloticus from 16 waterbodies across Ethiopia using 37 microsatellite loci with SSR-GBAS techniques. Results The samples are structured into three main clusters shaped either by biogeographic factors or stocking activities. High F ST values (Global F ST = 0.438) between populations indicate a high level of genetic differentiation and may suggest long term isolation even within the same drainage systems. Natural populations of the Omo-Turkana system and the lakes in the Southern Main Ethiopian Rift showed the highest genetic variability while low variability was found in stocked populations of lakes Hora, Hashenge and Hayq. Conclusions The results presented herein, may provide an essential basis for the management and conservation of the unique genetic resources in northern East Africa, and advance our understanding of biodiversity, phylogeny, evolution and development towards phylogenetically more accurate taxonomic classifications.
Background Despite progress in genomic analysis of spiders, their chromosome evolution is not satisfactorily understood. Most information on spider chromosomes concerns the most diversified clade, entelegyne araneomorphs. Other clades are far less studied. Our study focused on haplogyne araneomorphs, which are remarkable for their unusual sex chromosome systems and for the co-evolution of sex chromosomes and nucleolus organizer regions (NORs); some haplogynes exhibit holokinetic chromosomes. To trace the karyotype evolution of haplogynes on the family level, we analysed the number and morphology of chromosomes, sex chromosomes, NORs, and meiosis in pholcids, which are among the most diverse haplogyne families. The evolution of spider NORs is largely unknown. Results Our study is based on an extensive set of species representing all major pholcid clades. Pholcids exhibit a low 2n and predominance of biarmed chromosomes, which are typical haplogyne features. Sex chromosomes and NOR patterns of pholcids are diversified. We revealed six sex chromosome systems in pholcids (X0, XY, X 1 X 2 0, X 1 X 2 X 3 0, X 1 X 2 Y, and X 1 X 2 X 3 X 4 Y). The number of NOR loci ranges from one to nine. In some clades, NORs are also found on sex chromosomes. Conclusions The evolution of cytogenetic characters was largely derived from character mapping on a recently published molecular phylogeny of the family. Based on an extensive set of species and mapping of their characters, numerous conclusions regarding the karyotype evolution of pholcids and spiders can be drawn. Our results suggest frequent autosome–autosome and autosome–sex chromosome rearrangements during pholcid evolution. Such events have previously been attributed to the reproductive isolation of species. The peculiar X 1 X 2 Y system is probably ancestral for haplogynes. Chromosomes of the X 1 X 2 Y system differ considerably in their pattern of evolution. In some pholcid clades, the X 1 X 2 Y system has transformed into the X 1 X 2 0 or XY systems, and subsequently into the X0 system. The X 1 X 2 X 3 0 system of Smeringopus pallidus probably arose from the X 1 X 2 0 system by an X chromosome fission. The X 1 X 2 X 3 X 4 Y system of Kambiwa probably evolved from the X 1 X 2 Y system by integration of a chromosome pair. Nucleolus organizer regions have frequently expanded on sex chromosomes, most probably by ectopic recombination. Our data suggest the involvement of sex chromosome-linked NORs in achiasmatic pairing.
Background Edge effects can influence species composition and community structure as a result of changes in microenvironment and edaphic variables. We investigated effects of habitat edges on vegetation structure, abundance and body mass of one vulnerable Microcebus species in northwestern Madagascar. We trapped mouse lemurs along four 1000-m transects (total of 2424 trap nights) that ran perpendicular to the forest edge. We installed 16 pairs of 20 m² vegetation plots along each transect and measured nine vegetation parameters. To determine the responses of the vegetation and animals to an increasing distance to the edge, we tested the fit of four alternative mathematical functions (linear, power, logistic and unimodal) to the data and derived the depth of edge influence (DEI) for all parameters. Results Logistic and unimodal functions best explained edge responses of vegetation parameters, and the logistic function performed best for abundance and body mass of M. ravelobensis. The DEI varied between 50 m (no. of seedlings, no. of liana, dbh of large trees [dbh ≥ 10 cm]) and 460 m (tree height of large trees) for the vegetation parameters, whereas it was 340 m for M. ravelobensis abundance and 390 m for body mass, corresponding best to the DEI of small tree [dbh < 10 cm] density (360 m). Small trees were significantly taller and the density of seedlings was higher in the interior than in the edge habitat. However, there was no significant difference in M. ravelobensis abundance and body mass between interior and edge habitats, suggesting that M. ravelobensis did not show a strong edge response in the study region. Finally, regression analyses revealed three negative (species abundance and three vegetation parameters) and two positive relationships (body mass and two vegetation parameters), suggesting an impact of vegetation structure on M. ravelobensis which may be partly independent of edge effects. Conclusions A comparison of our results with previous findings reveals that edge effects are variable in space in a small nocturnal primate from Madagascar. Such an ecological plasticity could be extremely relevant for mitigating species responses to habitat loss and anthropogenic disturbances.
Predictor variables and their explanation used in analysing variation in breeding time
Background Earlier breeding is one of the strongest responses to global change in birds and is a key factor determining reproductive success. In most studies of climate effects, the focus has been on large-scale environmental indices or temperature averaged over large geographical areas, neglecting that animals are affected by the local conditions in their home ranges. In riverine ecosystems, climate change is altering the flow regime, in addition to changes resulting from the increasing demand for renewable and clean hydropower. Together with increasing temperatures, this can lead to shifts in the time window available for successful breeding of birds associated with the riverine habitat. Here, we investigated specifically how the environmental conditions at the territory level influence timing of breeding in a passerine bird with an aquatic lifestyle, the white-throated dipper Cinclus cinclus. We relate daily river discharge and other important hydrological parameters, to a long-term dataset of breeding phenology (1978–2015) in a natural river system. Results Dippers bred earlier when winter river discharge and groundwater levels in the weeks prior to breeding were high, and when there was little snow in the catchment area. Breeding was also earlier at lower altitudes, although the effect dramatically declined over the period. This suggests that territories at higher altitudes had more open water in winter later in the study period, which permitted early breeding also here. Unexpectedly, the largest effect inducing earlier breeding time was territory river discharge during the winter months and not immediately prior to breeding. The territory river discharge also increased during the study period. Conclusions The observed earlier breeding can thus be interpreted as a response to climate change. Measuring environmental variation at the scale of the territory thus provides detailed information about the interactions between organisms and the abiotic environment.
Campaign members patrolling the raccoon traps in Asahikawa. In the car during patrolling, members discuss their thoughts about the capture and management situation
Interviewees and total interview time of each interviewee in each area
Implementation measures within the procedures of the raccoon trapping campaign in each city, Japan
The reference information available to officers in each city
Summary of challenges faced by officers and characteristics of management programs
Background The raccoon (Procyon lotor) is an invasive, non-native species in Japan. Throughout the country, it causes significant agricultural damage and negatively affects native biodiversity. Most of the responsibility for raccoon management lies with local government, and there are still many challenges to be overcome. Although raccoon populations have not been eradicated, intensive control campaigns such as focus on the early stages of invasion have controlled raccoons in some regions. To improve the national management of raccoons, we conducted a survey on raccoon management systems in local government departments considered to solve the challenges recognized in many areas. During 2014 and 2015, we surveyed three different municipal departments about raccoon management measures. The semi-structured interview survey covered two topics: (1) the situation leading up to the current management system; (2) the current management system. Results Our results describe the scope and methods used in raccoon management. The government staff managed raccoons using monitoring, employing a variety of methods, a range of budgets, and various role divisions. The management practices are similar in that they share a sense of taking precautions, collaborating with stakeholders, understanding that adequate methods must be used, and obtaining support from experts. Conclusions Our case studies reveal the challenges in raccoon management faced by local government officers in regions with active control. The management systems and methods that we surveyed seemed to be effective in solving problems in both developed and undeveloped areas.
Background Soil and microbial biomass stoichiometry plays an important role in understanding nutrient cycling in terrestrial ecosystems. However, studies on soil and microbial biomass stoichiometry in forests are rare. This study investigated the effect of tree species and topographic factors on the ecological stoichiometry of soil and soil microbial biomass. Methods Three types of forest stands (Quercus variabilis, Larix principis-ruprechtii, and Cotinus coggygria Scop.) in the Beiru River basin of Funiu Mountain were analyzed in September 2018. Six slope positions (sunny bottom slope, sunny middle slope, sunny top slope, shady bottom slope, shady middle slope, and shady top slope) were selected, and the total number of sampling plots was 108. The stoichiometric indices of soil and microbial biomass were determined. Results At a depth of 0–10 cm, the soil organic C contents in different stands followed the order of C. coggygria (27.7 ± 5.2 g/kg) > Q. variabilis (24.5 ± 4.9 g/kg) > L. principis-ruprechtii (20.8 ± 4.3 g/kg) (P < 0.05). The soil organic C contents at depths of 0–10 cm with different slope aspects and at different slope positions also showed significant differences (P < 0.05). The highest MBC content was observed at the slope bottom (1002 ± 157 mg/kg), whereas the lowest was observed at the slope top (641 ± 98.3 mg/kg). Redundancy analysis showed that the contribution of tree species to these differences was 57.1%, whereas that of topographical factors was 36.2%. Conclusions Tree species more significantly affected soil nutrients and microbial biomass C, N and P than did topographic factors.
Bioclimatic zones of South Kivu. The zones are indicated in different colors on the map. This figure was created by the authors using ArcMap version 10.6 (https ://deskt op.arcgi p/)
Receiver Operating Characteristic (ROC) curve and Area Under the Curve (AUC) value of MaxEnt modeling (100 runs)
Distribution of suitable areas of fall armyworm (Spodoptera frugiperda) in South Kivu, DRC. This figure was created by the authors using ArcMap version 10.6 (https ://deskt op.arcgi p/)
Contribution (a) and Permutation importance (b) of variables used as predictors in the fall armyworm (Spodoptera frugiperda) MaxEnt model. bio1: mean annual temperature; bio12: annual rainfall; bio4: temperature seasonality; llds: longest dry season duration
Occurrence records of fall armyworm (Spodoptera frugiperda) in South Kivu, DRC. Each point represents a maize field in which fall armyworm larvae were detected and collected. This figure was created by the authors using ArcMap version 10.6 (https ://deskt op.arcgi p/)
Background: The fall Armyworm (FAW) Spodoptera frugiperda (JE Smith), is currently a devastating pest throughout the world due to its dispersal capacity and voracious feeding behaviour on several crops. A MaxEnt species distributions model (SDM) was developed based on collected FAW occurrence and environmental data’s. Bioclimatic zones were identified and the potential distribution of FAW in South Kivu, eastern DR Congo, was predicted. Results: Mean annual temperature (bio1), annual rainfall (bio12), temperature seasonality (bio4) and longest dry season duration (llds) mainly affected the FAW potential distribution. The average area under the curve value of the model was 0.827 demonstrating the model efficient accuracy. According to Jackknife test of variable importance, the annual rainfall was found to correspond to the highest gain when used in isolation. FAWs’ suitable areas where this pest is likely to be present in South Kivu province are divided into two corridors. The Eastern corridor covering the Eastern areas of Kalehe, Kabare, Walungu, Uvira and Fizi territories and the Western corridor covering the Western areas of Kalehe, Kabare, Walungu and Mwenga. Conclusions: This research provides important information on the distribution of FAW and bioclimatic zones in South Kivu. Given the rapid spread of the insect and the climatic variability observed in the region that favor its development and dispersal, it would be planned in the future to develop a monitoring system and effective management strategies to limit it spread and crop damage. Keywords: Bioclimatic zone, Potential distribution, Spodoptera frugiperda, MaxEnt model, Environmental variables
Background Classifying and mapping vegetation are crucial tasks in environmental science and natural resource management. However, these tasks are difficult because conventional methods such as field surveys are highly labor-intensive. Identification of target objects from visual data using computer techniques is one of the most promising techniques to reduce the costs and labor for vegetation mapping. Although deep learning and convolutional neural networks (CNNs) have become a new solution for image recognition and classification recently, in general, detection of ambiguous objects such as vegetation is still difficult. In this study, we investigated the effectiveness of adopting the chopped picture method, a recently described protocol for CNNs, and evaluated the efficiency of CNN for plant community detection from Google Earth images. Results We selected bamboo forests as the target and obtained Google Earth images from three regions in Japan. By applying CNN, the best trained model correctly detected over 90% of the targets. Our results showed that the identification accuracy of CNN is higher than that of conventional machine learning methods. Conclusions Our results demonstrated that CNN and the chopped picture method are potentially powerful tools for high-accuracy automated detection and mapping of vegetation.
Fast growing invasive alien species are highly efficient with little investment in their tissues. They often outcompete slower growing species with severe consequences for diversity and community composition. The plant economics trait-based approach provides a theoretical framework, allowing the classification of plants with different performance characteristics. However, in multifaceted background, this approach needs testing. The evaluation and prediction of plant performance outcomes in ecologically relevant settings is among the most pressing topics to understand and predict ecosystem functioning, especially in a quickly changing environment. Temperature and nutrient availability are major components of the global environmental change and this study examines the response of growth economic traits, photosynthesis and respiration to such changes for an invasive fast-growing (Bromus hordaceus) and a slow-growing perennial (Bromus erectus) grass species. The fully controlled growth chamber experiment simulated temperature—and changes in nitrogen availability individually and in combination. We therefore provide maximum control and monitoring of growth responses allowing general growth trait response patterns to be tested. Under optimal nitrogen availability the slow growing B. erectus was better able to handle the lower temperatures (7 °C) whilst both species had problems at higher temperatures (30 °C). Stresses produced by a combination of heat and nutrient availability were identified to be less limiting for the slow growing species but the combination of chilling with low nutrient availability was most detrimental to both species. For the fast-growing invader B. hordeaceus a reduction of nitrogen availability in combination with a temperature increase, leads to limited growth performance in comparison to the slow-growing perennial species B.erectus and this may explain why nutrient-rich habitats often experience more invasion than resource-poor habitats.
Illustration of the experiments conducted to study the diversity of C.capitata associated fungi in Argan forest soil and nearby area and the pathogenicity of these fungal isolates against this pest pupae
Correlation of the infection percentages and generic richness with the physical and chemical properties of soil namely: texture (sand, silt, and clay), pH, electrical conductivity (EC), humidity (RH), organic matter content (OM) and carbon/nitrogen ratio (C/N)
Background: Studying the ecology of biocontrol-agents is a prerequisite to effectively control medfly (C. capitata) with entomopathogenic fungi. In this context, factors affecting the occurrence and distribution of medfly-associated entomopathogenic-fungi were studied. Soil samples (22) were collected from natural and cultivated areas of Souss-region Morocco. Results: A total of 260 fungal isolates belonging to 22 species and 10 genera were obtained by using medfly pupae as bait. Medfly-associated fungi were detected in all studied soils and pupae infection percentages ranged from 3.33% to 48%. Two genera, Fusarium and Beauveria were the most frequent with 83 isolates (32%) and 50 isolates (19.23%) respectively. Pathogenicity test of isolated species against medfly pupae showed high mortality rates up to 91% for some strains. Principal component analysis (PCA) demonstrated strong influence of origin, physical and chemical properties of soil on the abundance of these fungi. In general, medfly-associated fungi were more abundant in soils with moderate pH (7.5 to 8) having high sand and organic content. High relative humidity negatively influenced the abundance of these fungi. Both factors directly affected the fungal infection percentages in pupae. The response of fungi to these parameters varied among species. According to principal component analysis (PCA) the soils of argan fields and forests were more suitable for the development of medfly-associated fungi than citrus orchards. Conclusions: These results provide guidance on identifying suitable soils for effective application of entomopathogenic fungi as biological control agents. In summary, isolated indigenous strains seem to be a promising option to control C. capitata.
Background The Drosophila melanogaster mutant white-mottled is a well-established model for position-effect variegation (PEV). Transposition of the euchromatic white gene into the vicinity of the pericentric heterochromatin caused variegated expression of white due to heterochromatin spreading. The establishment of the euchromatin-heterochromatin boundary and spreading of silencing is regulated by mutually exclusive histone modifications, i.e. the methylations of histone H3 at lysine 9 and lysine 4. Demethylation of H3K4, catalysed by lysine-specific demethylase LSD1, is required for subsequent methylation of H3K9 to establish heterochromatin. LSD1 is therefore essential for heterochromatin formation and spreading. We asked whether drug-mediated inhibition of LSD affects the expression of white and if this induced change can be transmitted to those generations that have never been exposed to the triggering signal, i.e. transgenerational epigenetic inheritance. Results We used the lysine-specific demethylase 1 (LSD1)-inhibitor Tranylcypromine to investigate its effect on eye colour expression in consecutive generations by feeding the parental and F1 generations of the Drosophila melanogaster mutant white-mottled. Quantitative Western blotting revealed that Tranylcypromine inhibits H3K4-demethylation both in vitro in S2 cells as well as in embryos when used as feeding additive. Eye colour expression in male flies was determined by optical measurement of pigment extracts and qRT-PCR of white gene expression. Flies raised in the presence of Tranylcypromine and its solvent DMSO showed increased eye pigment expression. Beyond that, eye pigment expression was also affected in consecutive generations including F3, which is the first generation without contact with the inhibitor. Conclusions Our results show that feeding of Tranylcypromine and DMSO caused desilencing of white in treated flies of generation F1. Consecutive generations, raised on standard food without further supplements, are also affected by the drug-induced alteration of histone modifications. Although eye pigment expression eventually returned to the basal state, the observed long-lasting effect points to a memory capacity of previous epigenomes. Furthermore, our results indicate that food compounds potentially affect chromatin modification and hence gene expression and that the alteration is putatively inherited not only parentally but transgenerationally.
Background Tropical habitats and their associated environmental characteristics play a critical role in shaping macroinvertebrate communities. Assessing patterns of diversity over space and time and investigating the factors that control and generate those patterns is critical for conservation efforts. However, these factors are still poorly understood in sub-tropical and tropical regions. The present study applied a combination of uni- and multivariate techniques to test whether patterns of biodiversity, composition, and structure of macrobenthic assemblages change across different lagoon habitats (two mangrove sites; two seagrass meadows with varying levels of vegetation cover; and an unvegetated subtidal area) and between seasons and years. Results In total, 4771 invertebrates were identified belonging to 272 operational taxonomic units (OTUs). We observed that macrobenthic lagoon assemblages are diverse, heterogeneous and that the most evident biological pattern was spatial rather than temporal. To investigate whether macrofaunal patterns within the lagoon habitats (mangrove, seagrass, unvegetated area) changed through the time, we analysed each habitat separately. The results showed high seasonal and inter-annual variability in the macrofaunal patterns. However, the seagrass beds that are characterized by variable vegetation cover, through time, showed comparatively higher stability (with the lowest values of inter-annual variability and a high number of resident taxa). These results support the theory that seagrass habitat complexity promotes diversity and density of macrobenthic assemblages. Despite the structural and functional importance of seagrass beds documented in this study, the results also highlighted the small-scale heterogeneity of tropical habitats that may serve as biodiversity repositories. Conclusions Comprehensive approaches at the “seascape” level are required for improved ecosystem management and to maintain connectivity patterns amongst habitats. This is particularly true along the Saudi Arabian coast of the Red Sea, which is currently experiencing rapid coastal development. Also, considering the high temporal variability (seasonal and inter-annual) of tropical shallow-water habitats, monitoring and management plans must include temporal scales.
Geographical location of West Azerbaijan Province in northwestern Iran and common border with different countries. Sampling sites: 1. Hashiyeh Rood, 2: Hajib Khosh, 3: Kanibrazan Wetland, 4: Khor Khoreh, 5: Gapis, 6: Beytas, 7: Mahabad, 8: Milan, 9: Sangar, 10: Sangar2, 11: Keshmesh Tappeh, 12: Deimgeshlag, 13: Glik Gadim, 14: Yadegarloo, 15: Silvana, 16: Gojar, 17: Kooraneh, 18: Ghahramanloo, 19: Mavana, 20: Shaharchay Dam, 21: Talebin, 22: NAzloo(Original basic map has been prepared from https ://
The geographical properties of sampling localities
Background The characteristics of a larval habitat is an important factor which affects the breeding pattern and population growth of mosquitoes Information about the larval habitat characteristics and pupal productivity can be utilized for the surveillance of the level of population growth, species diversity, and preferred breeding sites of mosquitoes, which are important aspects of integrated vector control. In the present study, mosquito larvae were collected from 22 natural habitats in five counties of the West Azerbaijan Province in the Northwest of Iran during May–November 2018. Physicochemical characteristics of the habitats were investigated. These included alkalinity, chloride (Cl) content, water temperature (°C), turbidity (NTU), Total Dissolved Solids (TDS) (ppm), Electrical Conductivity (EC) (μS/cm), and acidity (pH). The index of affinity between the collected species was calculated using Fager & McGowan test. Results A total of 2715 specimens were collected and identified. Seven different species belonging to four genera were identified in our study sites. The species included, Culex pipiens Linnaeus 1758, Culex theileri Theobald 1903, Culex mimeticus Noé 1899, Culex modestus Ficalbi 1947, Culiseta longiareolata Macquart 1838, Anopheles maculipennis Meigen 1818complex, and Aedes caspius Pallas 1771. There was a significant difference in chloride content and water temperature preferences among the different species (P < 0.05). Also, there was no significant difference in pH, Alkalinity, Turbidity, TDS, and EC preferences among the different species (P > 0.05). The affinity between the pair of species Cx. mimeticus/Cs. longiareolata was 0.526. There was no affinity between other pairs of species or the affinity was very weak. Conclusions The physicochemical and biological characteristics of mosquito larval habitats play an important role in zoning of areas suitable for breeding and distribution. Surveillance of these characteristics can provide valuable information for entomological monitoring of mosquito vectors and for designing targeted control programs. Also, further studies should be undertaken in a wider geographical area, taking into account the complex characteristics of the physicochemical and ecological factors of the study area and their interaction with various mosquito species.
Comparison of Shannon diversity (alpha diversity) of the skin microbiota of wild living zebra finches. No effect of a bird age [n = 4 fully replicated families consisting of two adults (female, male) and two nestlings (offspring)], b sex (n = 5 families consisting of two adults and at least one nestling) and c family (n = 12 families with three to four individuals consisting of one or two adults and one or two nestlings) on Shannon diversity. X-axis labelling is representing the number of the families’ nest boxes. In the boxplots, the median is the bold horizontal line, the boxes refer to the interquartile range, and whiskers extend to max. 1.5 times the interquartile range, whereas dots are outliers
Impact of nest location on the skin microbiome. a Map of nest box locations (created with QGIS 3.8 [52]; both images are maps based on “Bing VirtualEarth”). Each circle indicates one nest box, marked with individual nest box (family) number. b Non-metric multidimensional ordination (nMDS) of skin microbiomes showing similarity between samples based on a Bray–Curtis similarity matrix (created with Primer-e [46]) The closer symbols appear on the plot, the more similar they are concerning their bacterial community. Blue-coloured shapes belong to samples from nest boxes 3, 4, 7 and 9 in the north, orange-coloured shapes to 13 and 15 in the west and green-coloured shapes to 17–30 in north-east. Symbols of same shape represent different members of a family (nest box). Axes of the nMDS plot are arbitrary and dimensionless
Taxonomic profiling of the skin microbiota of the zebra finch. The stack bar shows the most abundant families of the bacterial community based on 1233 OTUs using rarefied data (5536 read counts per sample). Low prevalence corresponds to ≤ 0.5% of the respective taxa relative to the absolute number of read counts. The order of the taxa in the legend reflects the relative average abundance of the respective taxa over all families. n = 12 families with three to four individuals consisting of one or two adults and one or two nestlings
Comparison of the similarity of bacterial communities on the skin between different family members (beta diversity). The parent-parent group comprises all pairs (male and female) that bred and raised offspring together (n = 5). The parents-offspring group includes all parents (either male or female) and their offspring, respectively (n = 16). The offspring-offspring group comprises all sibling pairs (n = 11). Asterisks indicate significant difference between groups (P < 0.05, post-hoc Wilcoxon rank sum tests). Similarities are based on Bray–Curtis similarity index. In the boxplots, the median is the bold horizontal line, the boxes refer to the interquartile range, and whiskers extend to max. 1.5 times the interquartile range
Background So far, large numbers of studies investigating the microbiome have focused on gut microbiota and less have addressed the microbiome of the skin. Especially in avian taxa our understanding of the ecology and function of these bacteria remains incomplete. The involvement of skin bacteria in intra-specific communication has recently received attention, and has highlighted the need to understand what information is potentially being encoded in bacterial communities. Using next generation sequencing techniques, we characterised the skin microbiome of wild zebra finches, aiming to understand the impact of sex, age and group composition on skin bacteria communities. For this purpose, we sampled skin swabs from both sexes and two age classes (adults and nestlings) of 12 different zebra finch families and analysed the bacterial communities. Results Using 16S rRNA sequencing we found no effect of age, sex and family on bacterial diversity (alpha diversity). However, when comparing the composition (beta diversity), we found that animals of social groups (families) harbour highly similar bacterial communities on their skin with respect to community composition. Within families, closely related individuals shared significantly more bacterial taxa than non-related animals. In addition, we found that age (adults vs. nestlings) affected bacterial composition. Finally, we found that spatial proximity of nest sites, and therefore individuals, correlated with the skin microbiota similarity. Conclusions Birds harbour very diverse and complex bacterial assemblages on their skin. These bacterial communities are distinguishable and characteristic for intraspecific social groups. Our findings are indicative for a family-specific skin microbiome in wild zebra finches. Genetics and the (social) environment seem to be the influential factors shaping the complex bacterial communities. Bacterial communities associated with the skin have a potential to emit volatiles and therefore these communities may play a role in intraspecific social communication, e.g. via signalling social group membership.
Plant Materials. Guerrilla clonal plants: a Typha orientalis; b Phragmites australis; c Sparganium stoloniferum; d Scirpus yagara. Phalanx clonal plants: e Acorus calamus; f Schoenoplectus tabernaemontani; g Butomus umbellatus
Effects of substrate heterogeneity on biomass accumulation and distribution in seven clonal plants. Values are a aboveground biomass, b belowground biomass, c total biomass, and d belowground/aboveground biomass ratio. Values are means ± SEs. The bars with different lowercase letters are significantly different
Effects of substrate heterogeneity on the morphological traits of seven clonal plants. Values are a plant height, b ramet number, c spacer diameter, and d spacer length. Values are means ± SEs. The bars with different lowercase letters are significantly different
Plant Materials. Guerrilla clonal plants: aTypha orientalis; bPhragmites australis; cSparganium stoloniferum; dScirpus yagara. Phalanx clonal plants: eAcorus calamus; fSchoenoplectus tabernaemontani; gButomus umbellatus
Schematic representation of soil substrate types. The light grey area in He was filled with lake sediment, and the dotted area was filled with sand. The shaded area in Ho represents an even mixture of the same amount of lake sediment and sand
Background Clonal plants are important in maintaining wetland ecosystems. The main growth types of clonal plants are the guerrilla and phalanx types. However, little is known about the effects of these different clonal growth types on plant plasticity in response to heterogeneous resource distribution. We compared the growth performance of clonal wetland plants exhibiting the two growth forms (guerrilla growth form: Scirpus yagara, Typha orientalis, Phragmites australis and Sparganium stoloniferum; phalanx growth form: Acorus calamus, Schoenoplectus tabernaemontani and Butomus umbellatus) grown in soil substrates that were either homogeneous or heterogeneous but had the same total amount of nutrients. Results We found that the morphological traits (plant height, ramet number, spacer diameter and length) and biomass accumulation of the guerrilla clonal plants (T. orientalis) were significantly enhanced by heterogeneity, but those of the phalanx clonal plants (A. calamus, S. tabernaemontani and B. umbellatus) were not. The results showed that the benefits of environmental heterogeneity to clonal plants may be correlated with the type of clonal structure. Conclusions Guerrilla clonal plants, which have a dispersed, flexible linear structure, are better suited to habitats with heterogeneous resources. Phalanx clonal plants, which form compact structures, are better suited to habitats with homogeneous resources. Thus, wetland clonal species with the guerrilla clonal structure benefit more from soil nutrient heterogeneity.
A honeybee foraging a Nicotiana glauca flower (photo taken by our group in Greece)
Average mortality of Apis mellifera young workers at 0, 4, and 8 days after feeding for 24h on N. glauca extracts
HILIC-ESI–MS/MS chromatogram of a 0.5 ppm standard solution of alkaloids mix
Background Invasive plant species pose a significant threat for fragile isolated ecosystems, occupying space, and consuming scarce local resources. Recently though, an additional adverse effect was recognized in the form of its secondary metabolites entering the food chain. The present study is elaborating on this subject with a specific focus on the Nicotiana glauca Graham (Solanaceae) alkaloids and their occurrence and food chain penetrability in Mediterranean ecosystems. For this purpose, a targeted liquid chromatography electrospray tandem mass spectrometric (LC–ESI–MS/MS) analytical method, encompassing six alkaloids and one coumarin derivative, utilizing hydrophilic interaction chromatography (HILIC) was developed and validated. Results The method exhibited satisfactory recoveries, for all analytes, ranging from 75 to 93%, and acceptable repeatability and reproducibility. Four compounds (anabasine, anatabine, nornicotine, and scopoletin) were identified and quantified in 3 N. glauca flowers extracts, establishing them as potential sources of alien bio-molecules. The most abundant constituent was anabasine, determined at 3900 μg/g in the methanolic extract. These extracts were utilized as feeding treatments on Apis mellifera honeybees, resulting in mild toxicity documented by 16–18% mortality. A slightly increased effect was elicited by the methanolic extract containing anabasine at 20 μg/mL, where mortality approached 25%. Dead bees were screened for residues of the N. glauca flower extracts compounds and a significant mean concentration of anabasine was evidenced in both 10 and 20 μg/mL treatments, ranging from 51 to 92 ng/g per bee body weight. Scopoletin was also detected in trace amounts. Conclusions The mild toxicity of the extracts in conjunction with the alkaloid and coumarin residual detection in bees, suggest that these alien bio-molecules are transferred within the food chain, suggesting a chemical invasion phenomenon, never reported before.
Haplotype networks (N#) of the lichenized green alga Diplosphaera chodatii from Payuk Lake, Canada using the internal transcribed spacer regions (ITS) 1, ITS2 and β-actin protein coding gene region markers. Different colors represent the different networks for each of the markers used. Letters followed by numbers correspond to the sample that was collected. Squares represent the first and dominant haplotype designated to a network, circles with samples represent related haplotypes (size is proportional to the number of samples that have the haplotype), and small hollow circles represent single base pair changes from the dominant haplotype
Distribution of haplotype subnetworks of a the internal transcribed spacer region 1 (ITS1), b the internal transcribed spacer region 2 (ITS2), and c β-actin protein gene of lichenized Diplosphaera chodatii in Payuk Lake, Manitoba. The colors represent different haplotype networks
Map of Payuk Lake divided into geographic sections to show the definitions of populations for four ecologically meaningful hypotheses used in analyses of population structure and gene flow. a Inflow-outflow-bay; b Bay topography; c Hydrology; d Wind. Base map source: publicly available datasets offered through CanVec (GeoGratis, Natural Resources Canada)
Background Landscape genetics is an interdisciplinary field that combines tools and techniques from population genetics with the spatially explicit principles from landscape ecology. Spatial variation in genotypes is used to test hypotheses about how landscape pattern affects dispersal in a wide range of taxa. Lichens, symbiotic associations between mycobionts and photobionts, are an entity for which little is known about their dispersal mechanism. Our objective was to infer the dispersal mechanism in the semi-aquatic lichen Dermatocarpon luridum using spatial models and the spatial variation of the photobiont, Diplosphaera chodatii . We sequenced the ITS rDNA and the β-actin gene regions of the photobiont and mapped the haplotype spatial distribution in Payuk Lake. We subdivided Payuk Lake into subpopulations and applied four spatial models based on the topography and hydrology to infer the dispersal mechanism. Results Genetic variation corresponded with the topography of the lake and the net flow of water through the waterbody. A lack of isolation-by-distance suggests high gene flow or dispersal within the lake. We infer the dispersal mechanism in D. luridum could either be by wind and/or water based on the haplotype spatial distribution of its photobiont using the ITS rDNA and β-actin markers. Conclusions We inferred that the dispersal mechanism could be either wind and/or water dispersed due to the conflicting interpretations of our landscape hypotheses. This is the first study to use spatial modelling to infer dispersal in semi-aquatic lichens. The results of this study may help to understand lichen dispersal within aquatic landscapes, which can have implications in the conservation of rare or threatened lichens.
Background The gradual conversion of rangelands into other land use types is one of the main challenges affecting the sustainable management of rangelands in Teltele. This study aimed to examine the changes, drivers, trends in land use and land cover (LULC), to determine the link between the Normalized Difference Vegetation Index (NDVI) and forage biomass and the associated impacts of forage biomass production dynamics on the Teltele rangelands in Southern Ethiopia. A Combination of remote sensing data, field interviews, discussion and observations data were used to examine the dynamics of LULC between 1992 and 2019 and forage biomass production. Results The result indicate that there is a marked increase in farm land (35.3%), bare land (13.8%) and shrub land (4.8%), while the reduction found in grass land (54.5%), wet land (69.3%) and forest land (10.5%). The larger change in land observed in both grassland and wetland part was observed during the period from 1995–2000 and 2015–2019, this is due to climate change impact (El-Niño) happened in Teltele rangeland during the year 1999 and 2016 respectively. The quantity of forage in different land use/cover types, grass land had the highest average amount of forage biomass of 2092.3 kg/ha, followed by wetland with 1231 kg/ha, forest land with 1191.3 kg/ha, shrub land with 180 kg/ha, agricultural land with 139.5 kg/ha and bare land with 58.1 kg/ha. Conclusions The significant linkage observed between NDVI and LULC change types (when a high NDVI value, the LULC changes also shows positive value or an increasing trend). In addition, NDVI value directly related to the greenness status of vegetation occurred on each LULC change types and its value directly linkage forage biomass production pattern with grassland land use types. 64.8% (grass land), 43.3% (agricultural land), 75.1% (forest land), 50.6% (shrub land), 80.5% (bare land) and 75.5% (wet land) more or higher dry biomass production in the wet season compared to the dry season.
Frequency distribution of the in-and out-degree values of each species in pollen transfer plant-plant networks. Different colours represent different locations: Eselsburger Tal (green), Hirschtal (orange), Reichenbach (purple). Different colour alpha values (i.e. shading) represent sampling date: early summer (0.4), mid-summer (0.7), late summer (1). The in-degree is the number of incoming links, i.e. number of species of which HP grains were found on the stigma. The out-degree is the number of outgoing links, i.e. the number of species to which HP grains were donated
Plant-plant networks based on pollen transfer patterns of eight sampled grassland communities. Each node represents one plant species and each link represents HP transfer between two species. Direction of arrows indicates HP transfer from donor to receptor species and width of arrows indicates the number of transferred pollen grains. Nodes with the same colour are in the same module within one community. Numbers in community names show sampling date: I = early summer, II = mid-summer, III = late summer. Eselsburger Tal I is not shown as no modules were detected. OOB: the estimate of error rate from random forest analysis shows the percentage of misclassifications, i.e. assignment to the wrong module. The three most important variables for the module classification are given for each community (Table 2). The full results of the random forest analysis are given in Additional file 1-5. For RB III, two solutions of the modularity algorithm (Blondel et al. 2008) are shown as both were equally likely: solution one with four modules / solution two with five modules because one module was split into two plant-plant networks (computed in Gephi version 0.9.2 [41] by using the Fruchterman Reingold layout)
Importance of measured floral traits for module separation based on random forest analysis
Correlation between the modularity of the pollen transfer plant-plant network and community parameters. Community parameters are: (a) bee species richness, (b) bee abundance, (c) bee diversity, (d) plant species richness, (e) flower abundance (ln-transformed) and (f) flower diversity. Diversity was measured as the Shannon–Wiener index. Different colours represent different locations: Eselsburger Tal (green), Hirschtal (orange), Reichenbach (purple). Each location was sampled once in early, mid and late summer. Black lines are lines of best fit derived from linear models. Adjusted R² are given in the lower right-hand corner of each graph (full results shown in Additional file 1-4). ns = non-significant, *p < 0.05, **p < 0.01, ***p < 0.001
Background: In flowering communities, plant species commonly share pollinators and therefore plant individuals receive heterospecific pollen (HP). However, the patterns of HP transfers can deviate from patterns of plant-pollinator visitations. Although flower-visitor interactions are known to be mediated by floral traits, e.g. floral size or nectar tube depth, the explanatory power of these traits for HP transfer patterns remains elusive. Here, we have explored pollen transfer patterns at three sites in Southern Germany on three dates (early, mid and late summer). At the plant level, we tested whether flower abundance and floral traits are correlated with HP reception and donation. At the community level, we determined whether flower and bee diversity are correlated with network modularity and whether floral traits explain the module affiliation of plant species. We collected the stigmas of flowering plant species, analysed HP and conspecific pollen (CP) loads and measured floral traits, flower and bee diversity. Results: Our results show that the degree and intensity of HP reception or donation at the plant level do not correlate with floral traits, whereas at the community level, the module affiliation of who is sharing pollen with whom is well-explained by floral traits. Additionally, variation in network modularity between communities is better explained by plant diversity and abundance than by bee diversity and abundance. Conclusions: Overall, our results indicate that floral traits that are known to mediate flower-visitor interactions can improve our understanding of qualitative HP transfer but only provide limited information about the quantity of HP transfer, which more probably depends on other floral traits, flower-visitor identity or community properties.
The locations of the plant species collected in this synthetic analysis. All the plant species are distributed within the East Himalaya-Hengduan Mountains region (including northwest of Yunnan province, west of Sichuan province, southeast Tibet and south of Gansu province). The map is from Natural Earth, which was built through a collaboration of many volunteers and is supported by NACIS (North American Cartographic Information Society), and is free for use in any type of project,
Distribution of pollination limitation of collected plants in the East Himalaya-Hengduan Mountains. The black circles represent the species that were not pollination limited (the effect size is negative or the 95% confidence interval overlap zero), and the white circles represent pollination-limited species (the effect size is positive and the 95% confidence interval did not overlap zero)
Effect size and the 95% confidence interval of the pollination limitation in the East Himalaya-Hengduan Mountains. The sample sizes of each category, the within-category heterogeneity (Qm) and P value are presented
Correlation between elevation and the degree of pollination limitation. The within-category heterogeneity (Qm), P value and correlation coefficient are presented. Red dash line is the abline, the black solid line is the fitting line between elevation and the degree of pollen limitation, 2 black dash lines show the interval confidence
Background Pollen limitation occurs widely and has an important effect on flowering plants. The East Himalaya-Hengduan Mountains region is a global biodiversity hotspot. However, to our knowledge, no study has synthetically assessed the degree of pollen limitation in this area. The present study aims to reveal the degree of pollen limitation for the flowering plants growing on East Himalaya-Hengduan Mountains and to test whether the reproductive features or the elevation is closely correlated with the degree of pollen limitation in this area. Results We complied data from 76 studies, which included 96 species and 108 independent data records. We found that the flowering plants in this area undergo severe pollen limitation [overall Hedges’ d = 2.004, with a 95% confidence interval (1.3264, 2.6743)] that is much higher than that of the flowering plants growing in many other regions around the world. The degree of pollen limitation was tested to determine the correlation with the capacity for autonomous self-reproduction and with the pollination pattern (generalized vs. specialized pollination) of plants. In addition, we found a clear relationship between elevation and the degree of pollen limitation, which indicates that plants might undergo more severe pollen limitation in relatively high places. Conclusions This paper is the first to address the severe pollen limitation of the flowering plants growing in East Himalaya-Hengduan Mountains region. Moreover, we reveal the positive correlation between elevation and the degree of pollen limitation.
Mean δ 2 H values of fur and wing tissue for all 208 Miniopterus schreibersii with standard deviations in brackets (see Additional file 1: S1 and S3 for location of sites)
Proportion of Miniopterus schreibersii predicted as being ‘local’ and ‘non-local’ at each site in autumn and spring. A bat was classified as ‘non-local’ if either the wing or fur sample was predicted as ‘non-local’. The size of the pie chart is proportional to the sample size. The species’ distribution map as currently described by the IUCN [2] is shown in green
Examples of Miniopterus. schreibersii probability (p value—values ranging from 0 to 1) maps of geographical assignments (sampling sites in blue areas indicate that the site was rejected as a source of origin for the bat or group of bats). Probability maps of geographical assignment based on a a group of bats predicted as being ‘local’; b an individual sampled at the same site as a predicted as ‘non-local’; c an individual bat predicted as being ‘local’ based on the wing sample; and d the same individual bat predicted as being ‘non-local’ based on the fur sample
Background The Schreiber’s bat, Miniopterus schreibersii, is adapted to long-distance flight, yet long distance movements have only been recorded sporadically using capture-mark-recapture. In this study, we used the hydrogen isotopic composition of 208 wing and 335 fur specimens from across the species' European range to test the hypothesis that the species migrates over long distances. Results After obtaining the hydrogen isotopic composition (δ²H) of each sample, we performed geographic assignment tests by comparing the δ²H of samples with the δ²H of sampling sites. We found that 95 bats out of 325 showed evidence of long-distance movement, based on the analysis of either fur or wing samples. The eastern European part of the species range (Greece, Bulgaria and Serbia) had the highest numbers of bats that had moved. The assignment tests also helped identify possible migratory routes, such as movement between the Alps and the Balkans. Conclusions This is the first continental-scale study to provide evidence of migratory behaviour of M. schreibersii throughout its European range. The work highlights the need for further investigation of this behaviour to provide appropriate conservation strategies.
Human-wildlife conflict occurs when the needs and behavior of wildlife impact negatively on humans or when humans negatively affect the needs of wildlife. To explore the nature, causes and mitigations of human wildlife conflict, the coexistence between human and wildlife assessment was conducted around Bale Mountains National Park. Data were collected by means of household questionnaires, focus group discussion, interview, field observation and secondary sources. The nature and extent of human wildlife conflict in the study area were profoundly impacted humans, wild animal and the environment through crop damage, habitat disturbance and destruction, livestock predation, and killing of wildlife and human. The major causes of conflict manifested that agricultural expansion (30%), human settlement (24%), overgrazing by livestock (14%), deforestation (18%), illegal grass collection (10%) and poaching (4%). To defend crop raider, farmers have been practiced crop guarding (34%), live fencing (26%), scarecrow (22%), chasing (14%), and smoking (5%). However, fencing (38%), chasing (30%), scarecrow (24%) and guarding (8%) were controlling techniques to defend livestock predator animals. As emphasized in this study, human-wildlife conflicts are negative impacts on both human and wildlife. Accordingly, possible mitigate possibilities for peaceful co-existence between human and wildlife should be create awareness and training to the local communities, identifying clear border between the closure area and the land owned by the residents, formulate rules and regulation for performed local communities, equal benefit sharing of the local communities and reduction of human settlement encroachment into the national park range. Generally, researcher recommended that stakeholders and concerned bodies should be creating awareness to local community for the use of wildlife and human-wildlife conflict mitigation strategies.
Embryonic and early larval development in C. maculatus as visualized with (a-p) confocal laser scanning microscopy and (q-s) light microscopy. Embryos stained with SYTOX Green fluorescent nucleic acid stain: (a-f) selected cleavages: 2, 16, 64, 256, 1024, and 4096 nuclei, respectively; (g) a mitotic wave during transition from 4096 to 8192 nuclei; (h) invagination of a transverse furrow during gastrulation; (i) a three-layered, segmented germ band; (j-l) germ band extension; (m) germ band retraction; (n) the end of germ band retraction and the onset of dorsal closure; (o-p) dorsal closure; in paired images (i-p), the upper and the lower parts correspond to a ventral and a dorsal view, respectively, and belong to different but same-stage embryos, except for (n) that shows the same embryo from both sides. Late embryos at different stages of sclerotization and hatching: (q) reddening of the mandibular tips, ventral view; (r) hatching, viewed ventrolaterally -note that the fully formed larva has rotated 180° and is now emerging through the former dorsal side of the egg; (s) freshly hatched first instar larva, ventral view
Transition from one developmental stage to the next at two incubation temperatures: (a, b) 20 °C and (c, d) 29 °C. Logistic regression curves are based on maximum penalized likelihood (a, c) or usual maximum likelihood (b, d). Each data point refers to one sample, i.e., a group of eggs laid during a 20-min period, but one and the same sample may appear on the graph more than once if it was used for plotting different curves. Logistic curves for the other three incubation temperatures can be found in Additional file 4
Thermal reaction norms for adult body mass in C. maculatus after rearing at five constant temperatures. Symbols with bars denote means ± SD and are slightly set apart along the temperature axis for clarity
Thermal reaction norms for (a) embryonic stages until the completion of dorsal closure, (b, c) post-dorsal-closure embryonic stages, and (d) total embryonic development. Bold solid lines with R² values shown near them are plotted based on the results of linear regression analyses, which are summarized in Table 2. Dashed lines designate either linear extrapolation beyond the studied temperature range or provisional second-order polynomials shown for illustration purposes
Thermal reaction norms for (a) larval, (b) pupal, and (c) adult teneral development in C. maculatus. Data points correspond to individual developmental rates. Regression lines in a and b are plotted based on GLS model parameters fit by REML. The dashed curve in c refers to a second-order polynomial, plotted for illustration purposes
Background: The thermal plasticity of life-history traits receives wide attention in the recent biological literature. Of all the temperature-dependent traits studied, developmental rates of ectotherms are especially often addressed, and yet surprisingly little is known about embryonic responses to temperature, including changes in the thermal thresholds and thermal sensitivity during early development. Even postembryonic development of many cryptically living species is understood superficially at best. Results: This study is the first to estimate the exact durations of developmental stages in the cowpea seed beetle C. maculatus from oviposition to adult emergence at five permissive constant temperatures from 20 to 32 °C. Early embryonic development was tracked and documented by means of destructive sampling and subsequent confocal imaging of fluorescently stained specimens. Late embryonic and early larval development was studied with the use of destructive sampling and light microscopy. Well-resolved temporal series based on thousands of embryos allowed precise timing of the following developmental events: formation of the blastoderm; formation, elongation, and retraction of the germ band; dorsal closure; the onset and completion of sclerotization of the cuticle; hatching, and penetration of the first-instar larva into the cowpea seed. Pupation and adult eclosion were observed directly through an incision in the seed coat. The thermal phenotype of C. maculatus was found to vary in the course of ontogeny and different stages scaled disproportionately with temperature, but pitfalls and caveats associated with analyses of relative durations of individual stages are also briefly discussed. Conclusion: Disproportionate changes in developmental durations with temperature may have important implications when study design requires a high degree of synchronization among experimental embryos or when the occurrence of particular stages in the field is of interest, as well as in any other cases when development times need to be estimated with precision. This work provides one of the first examples of integration of embryological techniques with ecophysiological concepts and will hopefully motivate similar projects in the future. While experiments with Drosophila continue to be the main source of information on animal development, knowledge on other model species is instrumental to building a broader picture of developmental phenomena.
Background: Vertebrate-mediated seed dispersal is probably the main long distance dispersal mode. Through endozoochory, large mammals act as mobile links between habitats within and among forest patches. Along with other factors, their feeding regimes do affect their contribution as dispersal vectors. We conducted a cross-species comparative experiment involving two herbivores, red deer and roe deer; and two opportunistic omnivores, wild boar and brown bear, all occurring in the forest and steppe-forest ecotone habitats of the south-eastern Caspian region. We compared their role as endozoochorous seed dispersal agents by monitoring seedling emergence in their dungs under greenhouse and natural conditions. Results: In total, 3078 seedlings, corresponding to 136 plant taxa sprouted from 445 paired dung sub-samples, under greenhouse and natural conditions. Only 336 seedlings, corresponding to 36 plant taxa, emerged under natural conditions, among which five taxa did not appear under greenhouse conditions. Graminoids and forbs composed 91% of the seedlings in the greenhouse whereas shrubs were more abundant under natural conditions, representing 55% of the emerged seedlings. Under greenhouse conditions, first red deer and then wild boar dispersed more species than the other two mammals, while under natural conditions brown bear was the most effective vector. We observed remarkably higher species richness and seedling abundance per dung sub-sample under buffered greenhouse conditions than we did under natural conditions. Conclusions: The four sympatric mammals studied provided different seed dispersal services, both in terms of seedling abundance and species richness and may therefore be regarded as complementary. Our results highlight a positive bias when only considering germination under buffered greenhouse conditions. This must be taken into account when planning management options to benefit plant biodiversity based on the dispersal services concluded from greenhouse experiments.
Background Salvia is a large, diverse, and polymorphous genus of the family Lamiaceae, comprising about 900 ornamentals, medicinal species with almost cosmopolitan distribution in the world. The success of Salvia limbata seed germination depends on a numerous ecological factors and stresses. We aimed to analyze Salvia limbata seed germination under four ecological stresses of salinity, drought, temperature and pH, with application of artificial intelligence modeling techniques such as MLR (Multiple Linear Regression), and MLP (Multi-Layer Perceptron). The S.limbata seeds germination was tested in different combinations of abiotic conditions. Five different temperatures of 10, 15, 20, 25 and 30 °C, seven drought treatments of 0, −2, −4, −6, −8, −10 and −12 bars, eight treatments of salinity containing 0, 50, 100.150, 200, 250, 300 and 350 mM of NaCl, and six pH treatments of 4, 5, 6, 7, 8 and 9 were tested. Indeed 228 combinations were tested to determine the percentage of germination for model development. Results Comparing to the MLR, the MLP model represents the significant value of R ² in training (0.95), validation (0.92) and test data sets (0.93). According to the results of sensitivity analysis, the values of drought, salinity, pH and temperature are respectively known as the most significant variables influencing S. limbata seed germination. Areas with high moisture content and low salinity in the soil have a high potential to seed germination of S. limbata . Also, the temperature of 18.3 °C and pH of 7.7 are proposed for achieving the maximum number of germinated S. limbata seeds. Conclusions Multilayer perceptron model helps managers to determine the success of S.limbata seed planting in agricultural or natural ecosystems. The designed graphical user interface is an environmental decision support system tool for agriculture or rangeland managers to predict the success of S.limbata seed germination (percentage) in different ecological constraints of lands.
Path diagram of the best-fitted overall model for tarsus asymmetry (SEM). The number associated with each arrow is the parameter estimate. Thick solid lines are significant paths (P < 0.05), dashed lines are non-significant. The number indicates non-standardized parameter estimates; the number in parenthesis indicate the standard error. (Path diagrams of species-specific models, test statistics and full SEM results are detailed in Additional file 1: Tables S2-S5, Figs. S3, S4)
Mean parasite prevalence and median parasitemia of the seven avian host species. a Mean parasite prevalence (bars indicate 95% Confidence Intervals) and b median parasitemia of the seven avian host species within the beech forests of Schorfheide-Chorin, Germany, separated per forest category. Groups sharing a letter are not significantly different after Tukey post-hoc (Sample size: C. caeruleus n = 34, E. rubecula n = 74, F. coelebs n = 44, P. major n = 86, S. atricapilla n = 62, T. merula n = 59, T. philomelos n = 39)
Background: Forest habitats are important biodiversity refuges for a wide variety of bird species. Parasitism may modulate host species presence and abundance, and parasite effects can change according to forest management practices. Such processes are not well studied in vector-borne avian haemosporidians. We analyzed the effects of forest management on bird-dipteran-haemosporidian interactions, using seven common bird species in managed and unmanaged beech forest habitats in northeastern Germany. We assumed that forest structural heterogeneity affects parasite population parameters in avian hosts (i.e., prevalence and parasitemia), through its effect on the condition of the avian host but also through varying vector abundances. Results: Parasite prevalence was high (about 80%) and homogeneous across different beech forest categories (i.e., young, old, unmanaged) and for all bird species, except Erithacus rubecula (35%). Parasitemia varied across bird species but not across forest categories within each avian species (lowest parasitemia were found in E. rubecula, Turdus merula, and Turdus philomelos). In our study system, we found that vector abundance was not the main driver of parasite dynamics. We found that forest structure affects parasite infection probability directly and potentially host condition via available resources that have to be used either to combat infections (i.e., high parasitemia) or to maintain a good body condition. Conclusions: The effects of each of the predictors were bird species-specific, and we found that Diptera vectors were not the foremost influence in our host-vector-parasite system. Effects of forest habitat variables indicated that for most bird species in this study, habitat regulation of infection probability was more likely (i.e., E. rubecula, Fringilla coelebs, Sylvia atricapilla), whereas for Parus major habitat characteristics impacted first individuals' body condition and subsequently the probability of infection. Our findings emphasize the need of species-specific analyses and to use continuous forest structural parameters (e.g., the proportion of gap, south facing aspect) to better understand habitat and land use effects on host-vector-parasite dynamics.
Potential distribution of Zanthoxylum bungeanum Maxim. in China (modified from Yuan et al. [16]. Written permission was obtained with license number of 4881970412036)
Species occurrence records (modified from Yuan et al. [16]. Written permission was obtained with license number of 4881970412036). Triangle symbol represents natural distribution Zanthoxylum bungeanum Maxim. in China
The contribution of each main contribution factor in MaxEnt modeling
Importance of environmental variables to Zanthoxylum bungeanum Maxim. by Jackknife test
Response curves of environmental variables to distribution probability
Background: With the growth of economic benefits brought by Zanthoxylum bungeanum Maxim. and the increasing market demand, this species has been widely introduced and cultivated in China. It is important to scientifically select suitable areas for artificial planting and promotion, and to understand the status and potential of Z. bungeanum resources. Results: The maximum entropy (MaxEnt) model and ArcGIS technologies were used to analyze the climatic suitability of Z. bungeanum based on known distribution data, combined with environmental data in China. Z. bungeanum was mainly distributed in subtropical and mid-eastern warm temperate regions. The total suitable area (high and medium suitability) accounted for 32% of China's total land area, with high suitability areas composing larger percentage, reaching 1.93 × 106 km2. The suitable range (and optimum value) of the key environmental variables affecting the distribution of Z. bungeanum were the maximum temperature in February of 2.8-17.7 °C (10.4 °C), the maximum temperature in March of 8.6-21.4 °C (16.3 °C), the maximum temperature in December of 2.5-17.1 °C (9.9 °C), the maximum temperature in November of 7.7-22.2 °C (14.5 °C) and the mean temperature in March of 3.2-16.2 °C (12.0 °C). Conclusions: The model developed by MaxEnt was applicable to explore the environmental suitability of Z. bungeanum.
The seventh BMC Ecology competition attracted entries from talented ecologists from around the world. Together, they showcase the beauty and diversity of life on our planet as well as providing an insight into the biological interactions found in nature. This editorial celebrates the winning images as selected by the Editor of BMC Ecology and senior members of the journal’s editorial board. Enjoy!
Background: In this multidisciplinary study we present soil chemical, phytochemical and GIS spatial patterning evidence that fairy circles studied in three separate locations of Namibia may be caused by Euphorbia species. Results: We show that matrix sand coated with E. damarana latex resulted in faster water-infiltration rates. GC-MS analyses revealed that soil from fairy circles and from under decomposing E. damarana plants are very similar in phytochemistry. E. damarana and E. gummifera extracts have a detrimental effect on bacteria isolated from the rhizosphere of Stipagrostis uniplumis and inhibit grass seed germination. Several compounds previously identified with antimicrobial and phytotoxic activity were also identified in E. gummifera. GIS analyses showed that perimeter sizes and spatial characteristics (Voronoi tessellations, distance to nearest neighbour ratio, pair correlation function and L-function) of fairy circles are similar to those of fairy circles co-occurring with E. damarana (northern Namibia), and with E. gummifera (southern Namibia). Historical aerial imagery showed that in a population of 406 E. gummifera plants, 134 were replaced by fairy circles over a 50-year period. And finally, by integrating rainfall, altitude and landcover in a GIS-based site suitability model, we predict where fairy circles should occur. The model largely agreed with the distribution of three Euphorbia species and resulted in the discovery of new locations of fairy circles, in the far southeast of Namibia and part of the Kalahari Desert of South Africa. Conclusions: It is proposed that the allelopathic, adhesive, hydrophobic and toxic latex of E. damarana, E. gummifera, and possibly other species like E. gregaria, is the cause of the fairy circles of Namibia in the areas investigated and possibly in all other areas as well.
Effect of light availability on the number of vascular plant species (per 400 m 2 ) in the forest understorey. Depicted are the four different ways to quantify light availability: direct measurement (top left); estimated cover of canopy > 5 m (top right); hemisphere simulation based on terrestrial laser scanning data (bottom left); and crown projection area derived from typical crown sizes per species and their position in the plots (bottom right). Dashed lines indicate 95% confidence interval of the regression. Non-significant regressions are indicated by dashed lines (and dotted confidence lines)
Background Temperate forest understorey vegetation poses an excellent study system to investigate whether increases in resource availability lead to an increase in plant species richness. Most sunlight is absorbed by the species-poor tree canopy, making the much more species-rich understorey species inhabit a severely resource-limited habitat. Additionally, the heterogeneity of light availability, resulting from management-moderated tree composition and age structure, may contribute to species coexistence. One would therefore expect that the diversity in the herb layer correlates positively with either the overall light availability, or the light heterogeneity, depending on whether resource availability or heterogeneity are more important drivers of diversity. To test this idea, we assessed variability of light conditions in 75 forest plots across three ecoregions with four different methods. Results We correlated these data with vegetation relevés and found light availability to be strongly positively correlated with understorey plant species richness, as well as with understorey cover. Light variability (assessed with two approaches) within plots was positively correlated with transmittance, but did not improve the relationship further, suggesting that the main driver of species richness in this system is the overall resource availability. Two of the three beech-dominated regions exhibited near-identical effects of light transmittance, while the third, featuring pine alongside beech and thus with the longest gradient of transmittance and lowest species richness, displayed a weaker light response. Conclusions While site conditions are certainly responsible for the trees selected by foresters, for the resulting forest structure, and for the differences in plant species pools, our results suggest that light transmittance is a strong mediating factor of understorey plant species richness.
Hypothesized path model for how mating time ('MT') of reindeer is affected directly and indirectly by climatic variability from 1996 to 2013 in the Kutuharju herd, northern Finland. The definitions and time windows of the weather variables ('MinTemp' , 'Prec' , 'Snow') are provided in the Methods section, as well as the explanation of (a) the hypothesized paths. 'BW Sept ' represents the pre-rut body weight of males and females (measured in September), 'DENS' the population density, 'PM' the proportion of males in the herd and '♂ ASTR' the male age structure (see text for details). All lines in the diagram represent a specific linear mixed-effects model. The path model in (b) shows the standardized coefficients and SEs for paths associated with statistically significant effects. Nonsignificant paths (P > 0.05) shown as darker lines in panel (a) have been set as light gray lines in panel (b); significant paths with good evidence (P < 0.05) for an effect as thick solid lines (b) and paths with a weak effect (P ~ 0.05) as dotted line (b)
Inter-annual variation of mating time from 1996 to 2013 of a semi-domesticated reindeer population at Kutuharju, northern Finland. Fitted line as well as 95% confidence interval band are provided. The dates are expressed in Julian day (JD) starting January 1st. Data points were weighted by inverse variance (i.e. regression slopes)
Response of mating time ('MT') of a semi-domesticated reindeer population in northern Finland between 1996 and 2013 to (a) the total snow cover between 9 April and 20 May ('Snow'), (b) the minimum temperature between 12 and 25 July ('MinTemp'), (c) the amount of precipitation between 1 August and 25 September ('Prec'), and (d) the individuals' body weight in September ('BW Sept '). The reported temporal trends of those variables were (e) a decreasing snow cover in early spring, (f) a decreasing minimum temperature in the last 2 weeks of July, (g) less precipitation in August-September and (h) an increasing pre-rut body weight of individuals. All dates are expressed in Julian day (JD). Graphs are presented with the 95% confidence interval band around the fitted line
Background: The breeding time of many species has changed over the past 2-3 decades in response to climate change. Yet it is a key reproductive trait that affects individual's parturition time and reproductive success, and thereby population dynamics. In order to predict how climate change will affect species' viability, it is crucial to understand how species base their reproductive efforts on environmental cues. Results: By using long-term datasets of mating behaviours and copulation dates recorded since 1996 on a semi-domesticated reindeer population, we showed that mating time occurred earlier in response to weather conditions at different key periods in their annual breeding cycle. The mating time occurred earlier following a reducing snow cover in early spring, colder minimum temperatures in the last 2 weeks of July and less precipitation in August-September. Conclusions: The mediated effect of a reduced snow cover in early spring on improving individuals' pre-rut body weight through a better availability of late winter food and reduced costs of locomotion on snow would explain that mating time has occurred earlier overtime. A lower level of insect harassment caused by colder maximum temperatures in July might have caused an advance in mating time. Less precipitation in August-September also caused the mating time to occur earlier, although the direct effects of the last two weather variables were not mediated through the pre-rut body weight of individuals. As such, the causal effects of weather conditions on seasonal timing of animals are still unclear and other mechanisms than just body weight might be involved (e.g. socio-biological factors). The plastic response of reindeer mating time to climatic variability, despite supplemental feeding occurring in late April, demonstrated that environmental factors may have a greater influence on reproductive outputs than previously thought in reindeer.
The flight initiation distance (a) and the vigilance time (b) of pika response to the models of four of their native predators (wolf, fox, crow and saker falcon). Data presented are means with standard errors
The hiding time of pika response to the models of four of their native predators (wolf, fox, crow and saker falcon). Data presented are means with standard errors. Significant difference (based on a non-parametric multiple test at alpha < 0.05) is denoted by pairs of lower case letters
The Sample selection and the black wireframe is the active area of pikas. The range of active area of a pika family is about 470-680 m 2 in our study area
The Sample selection and the black wireframe is the active area of pikas. The range of active area of a pika family is about 470–680 m² in our study area
Four different taxidermy predator species models: a Tibetan fox (Vulpes ferrilata). b Wolf (Canis lupis). c Saker falcon (Falco cherrug). d Large-billed Crow (Corvus macrorhynchos)
Background: The ability of a prey species to assess the risk that a predator poses can have important fitness advantages for the prey species. To better understand predator–prey interactions, more species need to be observed to determine how prey behavioral responses differ in intensity when approached by different types of predators. The plateau pika (Ochotona curzoniae) is preyed upon by all predators occurring in its distribution area. Therefore, it is an ideal species to study anti-predator behavior. In this study, we investigated the intensity of anti-predator behavior of pikas in response to visual cues by using four predator species models in Maqu County on the eastern Qinghai- Tibetan Plateau. Results: The behavioral response metrics, such as Flight Initiation Distance (FID), the hiding time and the percentage of vigilance were significantly different when exposed to a Tibetan fox, a wolf, a Saker falcon and a large-billed crow, respectively. Pikas showed a stronger response to Saker falcons compared to any of the other predators. Conclusions: Our results showed that pikas alter their behavioral (such as FID, the hiding time and the vigilance) response intensity to optimally balance the benefits when exposed to different taxidermy predator species models. We conclude that pikas are able to assess their actual risk of predation and show a threat-sensitive behavioral response.
Background: Competition within and between social groups determines access to resources and can be inferred from space use parameters that reflect depletion of food resources and competitive abilities of groups. Using location data from 1998 to 2017, we investigated within- and between-group competition in 12 groups of wild mountain gorillas (Gorilla beringei beringei). As within-group feeding competition is expected to increase with group size, an increase in group size is predicted to lead to an increase in the size of annual home ranges and core areas, but to a decrease in fidelity (reuse of an area). Due to asymmetries in competitive abilities, larger groups are expected to have higher exclusivity (degree of non-shared space) of annual home ranges and core areas than smaller groups. Results: We found evidence of within-group feeding competition based on a positive relationship between group size and both annual home range and core area size as well as a negative relationship between group size and core area fidelity. Additionally, fidelity of core areas was lower than of home ranges. Between-group competition was inferred from a trend for groups with more members and more males to have more exclusive home ranges and core areas. Lastly, annual core areas were largely mutually exclusive. Conclusions: Our study suggests that non-territorial, group-living animals can have highly dynamic, long-term avoidance-based spacing patterns, both temporally and spatially, to maintain annual core area exclusivity among groups while concurrently shifting these areas annually within overlapping home ranges to avoid resource depletion. Despite ranging in larger home ranges and core areas, larger groups were able to maintain more exclusive ranges than smaller groups, suggesting a competitive advantage for larger groups in between-group competition in a non-territorial species. Together, these findings contribute to understanding how social animals make behavioral adjustments to mitigate the effects of intraspecific competition.
Background: Manure and biochar soil amendments have shown many benefits to soil quality and crop productivity. This study aimed to reveal the effects of biochar and manure applications on soil fertility improvement and crop productivity in yellow cinnamon soil. Results: This study based on a 5-year field experiment. Four treatments were designed, included the control (CK), biochar amendment, manure amendment, and both biochar and manure amendment (BM). The results showed that: after five years, both biochar and manure treatment improved soil structure by increasing soil mean weight diameter (MWD), and soil water and nutrient supply was also increased by increasing the contents of water content, available potassium and available phosphorus. The productivity was also enhanced as wheat yield under the biochar, manure, and BM treatments increased by 3.59-11.32% compared with CK. In addition, biochar and manure treatment increased soil microbial biomass carbon (MBC) by > 15%, and soil total nematode abundance was significantly increased. Furthermore, the nematode community structure was significantly affected by biochar and manure treatment, dominant trophic group in CK was herbivores, but bacterivores were dominant in the biochar and manure treatments. The distribution of nematode genera was closely related to soil chemical properties and microbial biomass. Increases in the Shannon's diversity index, and decreases in the dominance index and summed maturity index after the 5-year treatment indicated a sustainable soil ecosystem after the biochar and manure applications. Conclusions: These findings indicate that biochar and manure result in better soil quality and increased productivity in yellow cinnamon soil.
Background: Migrant birds travel between their breeding areas and wintering grounds by alternating energetically and physiologically demanding flights with periods of rest and fuelling, so-called stopovers. An important intrinsic factor influencing the decision to resume migration is the amount of energy stores available for the next flight. Correlative studies with free-flying birds and experimental studies with caged birds have shown that the amount of energy stores affects the day-to-day, within-day and the directional decision of departure. The methodological advantages of both the correlative and experimental approach are combined when radio-tagging many individuals on the same day and subsequently determining the departure decisions at a high spatiotemporal resolution. Making use of such a quasi-experimental approach with an automated radio-tracking system at stopover, we studied the effect of energy stores on departure decisions and whether they vary between species of different migration strategies experiencing contrasting time constraints. For this, we chose a long-distance migrant, the common redstart (Phoenicurus phoenicurus), and a medium-distance migrant, the European robin (Erithacus rubecula), because the former has to travel at relatively higher speed to reach its wintering ground in a reasonable time at the expense of relatively higher energetic costs for travelling than the latter. Results: Common redstarts with higher energy stores were more likely to resume migration than their conspecifics with lower energy stores, whereas this pattern was absent in the European robins. The amount of energy stores significantly affected the timing of departure within the day, with large energy stores yielding early departures in both species. Departure directions from the stopover site during the first night after capture were oriented towards the seasonally appropriate direction but were not affected by variation in energy stores. Conclusions: We demonstrate the importance of variation in energy stores on the departure decisions and that it may affect species with different migration strategies dissimilarly in autumn. Nevertheless, knowledge of other intrinsic factors, such as feeding conditions, health status and physiological consequences of previous flights, is additionally required to better understand the departure decisions of migrants, as this is the key to providing an overall assessment of the decision-making process.
An illustration of the visual contrast between seagrass meadows (left hand side) and bare sediment sandflats (right hand side). Picture taken by Roman Zajac at Kaipara harbour, New Zealand. The white rectangle encompasses 0.5 × 0.5 m
Correlation between species occurring in seagrass meadows (top) or bare sand flats (bottom) due to shared habitat preferences (left panel) or residual correlation (right panel) as modelled by LVM (see Table 1 for full species names). Results are based on the most parsimonious model. Only correlations which differ from 0 are shown, i.e. the larger the bubble size the more different from 0, where red indicates negative values and blue positive correlation
Background: Species distribution models are commonly used tools to describe diversity patterns and support conservation measures. There is a wide range of approaches to developing SDMs, each highlighting different characteristics of both the data and the ecology of the species or assemblages represented by the data. Yet, signals of species co-occurrences in community data are usually ignored, due to the assumption that such structuring roles of species co-occurrences are limited to small spatial scales and require experimental studies to be detected. Here, our aim is to explore associations among marine sandy-bottom sediment inhabitants and test for the structuring effect of seagrass on co-occurrences among these species across a New Zealand intertidal sandflat, using a joint species distribution model (JSDM). Results: We ran a JSDM on a total of 27 macrobenthic species co-occurring in 300,000 m2 of sandflat. These species represented all major taxonomic groups, i.e. polychaetes, bivalves and crustaceans, collected in 400 sampling locations. A number of significant co-occurrences due to shared habitat preferences were present in vegetated areas, where negative and positive correlations were approximately equally common. A few species, among them the gastropods Cominella glandiformis and Notoacmea scapha, co-occurred randomly with other seagrass benthic inhabitants. Residual correlations were less apparent and mostly positive. In bare sand flats shared habitat preferences resulted in many significant co-occurrences of benthic species. Moreover, many negative and positive residual patterns between benthic species remained after accounting for habitat preferences. Some species occurring in both habitats showed similarities in their correlations, such as the polychaete Aglaophamus macroura, which shared habitat preferences with many other benthic species in both habitats, yet no residual correlations remained in either habitat. Conclusions: Firstly, analyses based on a latent variable approach to joint distributions stressed the structuring role of species co-occurrences beyond experimental scales. Secondly, results showed context dependent interactions, highlighted by species having more interconnected networks in New Zealand bare sediment sandflats than in seagrass meadows. These findings stress the critical importance of natural history to modelling, as well as incorporating ecological reality in SDMs.
Background: Spatial conservation prioritisation (SCP) is a set of computational tools designed to support the efficient spatial allocation of priority areas for conservation actions, but it is subject to many sources of uncertainty which should be accounted for during the prioritisation process. We quantified the sensitivity of an SCP application (using software Zonation) to possible sources of uncertainty in data-poor situations, including the use of different surrogate options; correction for sampling bias; how to integrate connectivity; the choice of species distribution modelling (SDM) algorithm; how cells are removed from the landscape; and two methods of assigning weights to species (red-list status or prediction uncertainty). Further, we evaluated the effectiveness of the Egyptian protected areas for conservation, and spatially allocated the top priority sites for further on-the-ground evaluation as potential areas for protected areas expansion. Results: Focal taxon (butterflies, reptiles, and mammals), sampling bias, connectivity and the choice of SDM algorithm were the most sensitive parameters; collectively these reflect data quality issues. In contrast, cell removal rule and species weights contributed much less to overall variability. Using currently available species data, we found the current effectiveness of Egypt’s protected areas for conserving fauna was low. Conclusions: For SCP to be useful, there is a lower limit on data quality, requiring data-poor countries to improve sampling strategies and data quality to obtain unbiased data for as many taxa as possible. Since our sensitivity analysis may not generalise, conservation planners should use sensitivity analyses more routinely, particularly relying on more than one combination of SDM algorithm and surrogate group, consider correction for sampling bias, and compare the spatial patterns of predicted priority sites using a variety of settings. The sensitivity of SCP to connectivity parameters means that the responses of each species to habitat loss are important knowledge gaps.
Background: Although behavioral unpredictability is widely described within-individual variability in behavior, its adaptive significance is little understood. Using a dynamic state variable model, this study investigated the conditions under which behavioral unpredictability (a component of within-individual variability) in foraging behavior is advantageous. The model considers a situation in which a forager forages for a fixed period, represented by discrete time steps. The outcome of foraging may change the level of a state (e.g., size and fat storage) of the forager at each time step, and variability in the foraging outcome is assumed to be positively correlated with behavioral unpredictability. The probability of death at each time step is influenced by the state at the same time step. Reproduction occurs after all the foraging steps and is influenced by the state level of a forager at the time of reproduction. According to the expected utility hypothesis, the relationship (e.g., curvature) between the state and fitness will determine the role of behavioral unpredictability. In the model, the relationship was obtained by using the backward iteration method for each foraging time step. Results: State-dependent mortality adds curvature to the relationship between the state and fitness, which makes the effect of behavioral unpredictability on fitness either positive or negative. This conclusion holds for any state-dependent mortality (i.e., as long as mortality is not independent of the state factor). Given that state-dependent mortality is commonly described, conditions that benefit behavioral unpredictability are likely also common. Conclusions: When mortality depends on a state that is influenced by behavior, conditions that favor behavioral unpredictability may become common. How behavioral unpredictability influences the variability of behavioral outcomes is as important as how it influences the expectation of behavioral outcomes when studying the adaptive significance of behavioral unpredictability.
Estimated monarch eggs and larva by location and date. Visual representation of estimated monarch eggs and observed larva for each study location throughout the survey period. Designations for the first through fifth instar larva have been labeled M1-M5, respectively
Estimated queen eggs and larva by location and date. Visual representation of estimated queen eggs and observed larva for each study location throughout the survey period. Designations for the first through fifth instar larva have been labeled Q1-Q5, respectively
Milkweed condition by location and date. Stacked bar graphs representing the condition (B Budding, D Dehiscent, F Flowering, SP with Seedpod, SN Senescing, V Vegetative) of milkweed throughout the survey period by location
Monarch egg density as a function of Julian date. Temporal trends for monarch egg densities. The trends were significant for both Fisher and Stonewall County based on the best fitting GAMM model, the blue region represents the 95% confidence bands of the fitted line. The “geom_jitter” function was used in R to account for overplotting and allow for easier visualization of data points
Map of survey locations. Map depicting the location of the survey counties with respect to their location in Texas (top left). The relative sizes and locations of the Stonewall County survey sites are displayed at the top right and Fisher County site locations and relative sizes are bottom left. Milkweed were only surveyed along the 50 m x 4 m transect in Fisher1 due to the immense size of the plot. This figure was created by the authors using ArcMap version 10.8 (
Background: The monarch butterfly (Danaus plexippus) is a conspicuous insect that has experienced a drastic population decline over the past two decades. While there are several factors contributing to dwindling monarch populations, habitat loss is considered the most significant threat to monarchs. In the United States, loss of milkweed, particularly in the Midwest, has greatly reduced the available breeding habitat of monarchs. This has led to extensive efforts to conserve and restore milkweed resources throughout the Midwest. Recently, these research and conservation efforts have been expanded to include other important areas along the monarch's migratory path. Results: During the fall of 2018, we conducted surveys of monarch eggs and larvae through West Texas. We documented monarch and queen butterfly (Danaus gilippus) reproduction throughout the region and used the proportion of monarch and queen larva to estimate the number of monarch eggs. Peak egg densities for monarchs were as high as 0.78 per milkweed ramet after correction for the presence of queens. Despite our observations encompassing only a limited sample across one season, the peak monarch egg densities we observed exceeded published reports from when monarch populations were higher. Conclusions: To our knowledge, this is the first study to correct for the presence of queens when calculating the density of monarch eggs. This research also provides insight into monarch utilization of less well-known regions, such as West Texas, and highlights the need to expand the scope of monarch monitoring and conservation initiatives. While the importance of monarch research and conservation in the Midwest is unquestionable, more comprehensive efforts may identify new priorities in monarch conservation and lead to a more robust and effective overall strategy, particularly given the dynamic and rapidly changing global environment.
Top-cited authors
Florian Menzel
  • Johannes Gutenberg-Universität Mainz
Nico Blüthgen
  • Technische Universität Darmstadt
Carlo Costantini
  • Institute of Research for Development
Jean-Marie Fotsing
  • University of New Caledonia
Diego Ayala
  • Institute of Research for Development