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Quantifying functional biodiversity

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... Higher SLA was found to be associated with high-altitude wetland habitats. While higher values of SLA are associated with rapid acquisition of resources, lower values are associated with a conservative strategy (Pla et al. 2012). Plant communities in high-altitude areas have been reported to be dominated by species with a conservative attribute, while low altitudes tend to select for species with an acquisitive attribute (Pla et al. 2012). ...
... While higher values of SLA are associated with rapid acquisition of resources, lower values are associated with a conservative strategy (Pla et al. 2012). Plant communities in high-altitude areas have been reported to be dominated by species with a conservative attribute, while low altitudes tend to select for species with an acquisitive attribute (Pla et al. 2012). This reflects the contrast between plant species found in high-and low-altitude areas in terms of their role in ecosystem functioning. ...
... While SLA is a good surrogate for the ability of a plant to use light efficiently, plant height is a good proxy for the ability to compete for light (Weiher et al. 1999). However, the pattern of high SLA being associated with high-altitude environments found in the current study is contrary to the reports of it being associated with low altitudes (Pla et al. 2012). This is probably found because the high-altitude soils in Lesotho, which are associated with the basaltic parent material, are nutrient-rich while the sandstone-derived low-altitude soils are nutrient-poor (Mucina and Rutherford 2006). ...
Article
Understanding montane wetlands and their functioning is essential for biodiversity conservation and sustainable provision of ecosystem services. Plant functional traits represent species adaptations to specific environments and are considered the key mechanism by which individual species contribute to the functioning and subsequent provision of ecosystem services. This study characterises the Afromontane palustrine wetlands along the altitudinal gradient in Lesotho in terms of plant functional traits and composition. Wetland plant species are classified into functional types (PFTs) using their functional traits. Relationships of plant functional traits and PFTs with environmental factors are also explored. Plant species composition was assessed using the Braun-Blanquet method, while functional traits and environmental factors were assessed using protocols recommended in the literature. The data were analysed using clustering and ordination techniques. Eight PFTs were obtained from the functional classification of the species. The PFTs were dominated by C3 plants, particularly in high-altitude wetlands. The wetland plant communities in Lesotho exhibited the coexistence of species from different PFTs, highlighting functional differentiation to exploit microhabitat heterogeneity. Both functional traits and functional composition of communities were mainly influenced by altitude, longitude, slope and several edaphic factors. Because montane regions display greater sensitivity to changes in climate, alterations in wetland plant functional traits, PFTs and composition will possibly occur in the face of climate change. These alterations will result in modifications in montane wetland ecosystem functioning that include primary productivity and nutrient cycling, with subsequent changes in the delivery of ecosystem services.
... Finally, trait community-weighted means (TCWM) were calculated to quantify the proportion or weight of each trait modality in each sampled community (Table S3). TCWM is a good indicator of the expected functional value of one trait in a random community sample (Pla et al., 2012). ...
... Functional diversity (FD) between communities was quantified using the following five multi-trait functional indices (Villéger et al., 2008;Laliberté and Legendre, 2010;Pla et al., 2012): functional richness, divergence, evenness, and dispersion, and Rao's quadratic entropy. Functional richness (FRic) is the amount of functional space occupied by the community (Villéger et al., 2008), and functional evenness (FEve) measures the distribution of abundance within the functional trait space (Villéger et al., 2008). ...
Article
We evaluated the effect of global warming on invertebrate communities at high altitudes using data from the Careser system. We procured data on air temperature, which was obtained over 50 years at altitudes above 2600 m a.s.l., and data on water temperature, which was available for approximately 30 years. We sampled thrice in the past 20 years (2001, 2014, 2018) at three sampling sites (CR0-metakryal, CR1-hypokryal, CR2-glacio-rhithral) of the Careser glacier-fed stream and its main non-glacial tributary (CR1bis-krenal). Warmer climates were observed in the last decade compared to the 1980s, with a mean maximum summer air temperature (mTmax) increase of 1.7 °C at 2642 m a.s.l. and 1.8 °C at 2858 m a.s.l. Compared to air temperatures, the rise in water temperature was delayed by approximately 20 years; water mTmax started to increase in 2003, reaching 8.1 °C at 2642 m a.s.l. and 2.4 °C at 2858 m a.s.l in the year 2020. The invertebrate community exhibited a delayed response approximately 13 years from the water warming; there was a sequential increase in the number of taxa, Shannon diversity, and after 17 years, functional diversity. In the kryal sites, taxonomical and functional diversity changed more consistently than in the glacio-rhithral site in the same period, due to the arrival of taxa that were previously absent upstream and bearers of entirely new traits. Progressive taxonomical homogenisation was evident with decreasing glacial influence, mainly between glacio-rhithral and krenal sites. The numbers of Diamesa steinboecki, an insect that was adapted to the cold, declined in summer (water mTmax >6 °C and air mTmax >12 °C). This study highlights the mode and time of response of stream invertebrate communities to global warming in alpine streams and provides guidelines for analysing changes in the stream invertebrate communities of other glacial systems in alpine regions.
... Acknowledging the importance of FD as a better community descriptor, numerous indices have been developed and highlighted for quantifying the functional diversity of plant communities (Schleuter et al. 2010;Mouchet et al. 2010;Petchey and Gaston 2006;Zhang et al. 2012;Mason et al. 2003Mason et al. , 2005Villiger et al. 2008;Pla et al. 2011). They are univariate (single trait per species) or multivariate (many traits per species) with or without abundance. ...
... Besides, dendrogram based measures of functional diversity were also proposed constructing a functional dendrogram over trait data matrix by clustering and sum up the branch length to get functional diversity of the community Gaston 2002, 2006;Schmera 2006, 2007;Pla et al. 2008;Casanoves et al. 2008Casanoves et al. , 2011. Rao"s quadratic entropy They include the FD-R package that measures multiple traits for functional ecology (Laliberte and Shipley 2011) to calculate FRic, FEve, FDiv, FDis. ...
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Invasive alien species (IAS) poses a significant threat to plant biodiversity globally and even considered one of the largest threats to biodiversity, second to habitat loss. They behave as pioneer species in different landscapes, tolerant to disturbances, climatic conditions, high competitive potential and generalists in distribution. Their superior competitive ability results in the loss of native flora leading to extinction. The success of IAS generally attributed to differences in functional traits compared to less successful aliens as well as to native species. Several studies envisaged that the impacts of plant invasions are not universal and depend on the trait diversity of both, the introduced species and the resident community. Functional traits best describe the alien's success over natives , and they seem to be important attributes to conservation biology and ecosystem management. Moreover, their ecological impacts remain poorly understood due to lack of quantitative studies. In the present paper, we adopted the systematic literature review approach for collecting and analysing the scientific data. A total of 212 critical research papers and grey literature for last three decades were found meeting the aims, were collected from relevant sources. Present review emphasizes the differences in key functional traits between invasive alien plants and the native species which aid them to alter ecosystem functioning by modifying habitat according to their needs. We also focus on potential habitats for invasion based on a conceptual framework concerning response-effect traits. Review provides a quantitative assessment of invading species for their ecological performance , emerging problems and possible solution.
... Currently, descriptive statistics like ordination analyses are used to rank the respective contributions of different traits to temporal and spatial community responses, i.e. which traits are most responsive to environmental changes in time and space (Legendre and Legendre, 2012;Peres-Neto et al., 2003;Pla et al., 2011). In temporal dynamics, principal component analysis (PCA) is used to examine changes in a given community over time by examining the movement of the community along the main principal component axes, while the most responsive traits are inferred by ranking PCA loadings (Legendre and Legendre, 2012;Peres-Neto et al., 2003;Pla et al., 2011). ...
... Currently, descriptive statistics like ordination analyses are used to rank the respective contributions of different traits to temporal and spatial community responses, i.e. which traits are most responsive to environmental changes in time and space (Legendre and Legendre, 2012;Peres-Neto et al., 2003;Pla et al., 2011). In temporal dynamics, principal component analysis (PCA) is used to examine changes in a given community over time by examining the movement of the community along the main principal component axes, while the most responsive traits are inferred by ranking PCA loadings (Legendre and Legendre, 2012;Peres-Neto et al., 2003;Pla et al., 2011). Additionally, trait responsiveness can be inferred as the slope of the regression between trait abundance and time or an environmental gradient (Jamil et al., 2014;Noordijk et al., 2010). ...
Thesis
The ensemble of biological, geochemical, and physical processes that occur within ecosystems is driven by the interplay between biological communities and the abiotic environment. Explaining the spatial and temporal dynamics of biological communities in relation to environmental conditions is therefore essential for understanding ecosystem functioning, and ultimately for achieving sustainable development. In marine ecosystems, fish communities are key to ecosystem functioning, and fisheries provide livelihoods for over 10% of the world’s population. However, understanding the processes structuring fish communities remains difficult because community structure varies with both natural environmental fluctuations and, increasingly, human pressures. Effectively managing fisheries and marine ecosystems under global change therefore requires better characterizing fish community dynamics over time and space and disentangling the underlying drivers and mechanisms. While fish ecologists have traditionally relied on species-based approaches (i.e., taxonomic approaches) to study community structure, trait-based approaches (i.e., functional approaches) are increasingly used because they can provide better insight into community assembly and the mechanisms driving community responses. To meet this need for a better understanding of biodiversity dynamics, the present thesis took advantage of long-term scientific monitoring data to characterize the functional responses of fish communities to environmental gradients in the North Sea, Eastern English Channel, and Bay of Somme. All three ecosystems experienced temperature rises and oceanographic changes associated with a warming phase of the Atlantic Multidecadal Oscillation (AMO), which rapidly impacted fish community structure. Consistent biological responses were observed across the three ecosystems despite their different spatial scales, demonstrating that fish communities were affected by environmental change through bio-ecological traits associated with habitat preference and life history. In the North Sea and Eastern Channel, pelagic species were the most responsive and contributed largely to community dynamics, which is likely explained by their greater mobility, higher dispersal rates, and fewer habitat requirements. However, beyond habitat preference, species with r-selected life histories (e.g., low size and age at maturity, low parental investment, small offspring) had the fastest environmental responses whether or not they were pelagic, likely due to their rapid population turnover and generation time. Importantly, the way these species’ responses shaped community structure depended on environmental context. R-selected, pelagic species rapidly declined in the Bay of Somme and Eastern Channel, but rapidly increased in the North Sea. This likely reflects environmental suitability, indicating that after the phase change of the AMO, the Eastern Channel became a less favorable environment for these species, while the North Sea became more favorable. Thus, species with high mobility and fast life history cycles appear capable of rapidly tracking environmental conditions, shifting in abundance in response to environmental suitability. Additionally, as these ecosystems have warmed over the last 30 years, community responses were characterized by increases in mean thermal preference. Importantly, the amplitude of community changes was partially determined by communities’ initial structure and redundancy of bio-ecological traits, showing that community responses depended not only on environmental changes but also on biodiversity itself. Lastly, while fish community responses were consistently associated with climatic changes, historical fishing pressure on large-bodied, demersal species appeared to render fish communities more sensitive to environmental changes by increasing the relative of abundance of pelagic and r-selected species.
... Functional evenness (FEve): Functional evenness measures the regularity of spacing between species in the trait space volume and also the evenness in the distribution of the species abundance. FEve calculated as (Pla et al., 2012): ...
... Multi-trait functional diversity indices were computed after standardization of trait values, while a single functional trait index was calculated without standardization. Standardization was performed because studied traits differ in several orders of magnitude and scale of measurement (Pla et al., 2012). Furthermore, to determine the effect of elevation, aspect and slope (fixed effects) on different functional diversity measures, a mixed effects model (Bates et al., 2015) with 'Type III analysis of variance with Satterthwaite's method was used. ...
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Understanding plant species distribution patterns along environmental gradients is fundamental to managing ecosystems, particularly when habitats are fragmented due to intensive human land use pressure. The variation pattern of functional diversity of plant communities along the elevation gradient in the Dindin dry evergreen Afromontane forest was tested. Fifty four plots of 20 x 20 m (400 m2) established at 200 m intervals starting 2,300–2,900 m a. s. l. and woody species composition, and environmental variables were recorded. Nine functional diversity indices based on functional distances were employed to esimate functional diversity. The mixed effect model was used to determine the effect of elevation, aspect and slope on functional diversity indices. The results showed that functional diversity in communities varied greatly; functional diversity revealed a decrease with increasing elevation and a‘‘humped’’ pattern, with peak diversity appearing at middle elevation. Functional diversity was significantly correlated with elevation, slope, and aspect. Functional diversity was significantly correlated with species richness and evenness. Environmental filtering was important to the functional diversity pattern; the nine indices were all successful in the analysis of functional diversity in the plant community with different effectiveness, and modified functional attribute diversity, plot-based functional diversity, community based functional diversity, functional richness, and community weight mean of woody density performed better than the other four indices in this study.
... Finally, trait community-weighted means (TCWM) were calculated to quantify the proportion or weight of each trait modality in each sampled community (Table S3). TCWM is a good indicator of the expected functional value of one trait in a random community sample (Pla et al., 2012). ...
... Functional diversity (FD) between communities was quantified using the following five multi-trait functional indices (Villéger et al., 2008;Laliberté and Legendre, 2010;Pla et al., 2012): functional richness, divergence, evenness, and dispersion, and Rao's quadratic entropy. Functional richness (FRic) is the amount of functional space occupied by the community (Villéger et al., 2008), and functional evenness (FEve) measures the distribution of abundance within the functional trait space (Villéger et al., 2008). ...
Article
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It is known that pesticides and other organic pollutants are transported from lowlands and alpine valleys to high alpine summits, where they are stored in glaciers until melting occurs between July and September. In this study, we aimed to map glacial contamination by measuring the concentrations of currently used pesticides, synthetic fragrances, and polycyclic aromatic hydrocarbons (PAHs) in glacial and non-glacial meltwater from six sites in the Italian Alps located within the protected Adamello-Brenta Natural Park. We subsequently characterised the ecological risk of these contaminants to aquatic fauna. Chlorpyrifos, chlorpyrifos-methyl, terbuthylazine, galaxolide, tonalide, and PAHs were detected in July and September 2019 and 2020 across all sites. Risk characterisation indicated that PAHs posed a low risk to the alpine ecosystem at most of the sites, and medium risk was associated only with fluoranthene and pyrene at Mandrone in 2020. Regarding fragrances, herbicides, and chlorpyrifos-methyl, the calculated risk to aquatic biocenosis was acceptable under current European guidelines. Only chlorpyrifos posed an unacceptable risk to aquatic invertebrates at two sites: Amola (in July 2019) and Mandrone (in July and September 2019 and 2020). A risk refinement of chlorpyrifos, calculated using the species sensitivity distribution, indicated an acceptable level of risk, as concentrations were consistently below the effect level. Chlorpyrifos is not the only potential threat to Alpine aquatic ecosystems; therefore, it is advised to continue monitoring other equally potentially dangerous compounds that could reach high-altitude environments through medium-range atmospheric transport. To preserve the ecological and social value of the Adamello-Brenta Natural Park, natural capital is a priority. In this context, the results of this study assume strategic importance in supporting the development of future environmental conservation initiatives and water management policies.
... Functional evenness (FEve): Functional evenness measures the regularity of spacing between species in the trait space volume and also the evenness in the distribution of the species abundance. FEve calculated as (Pla et al., 2012): ...
... Multi-trait functional diversity indices were computed after standardization of trait values, while a single functional trait index was calculated without standardization. Standardization was performed because studied traits differ in several orders of magnitude and scale of measurement (Pla et al., 2012). Furthermore, to determine the effect of elevation, aspect and slope (fixed effects) on different functional diversity measures, a mixed effects model (Bates et al., 2015) with 'Type III analysis of variance with Satterthwaite's method was used. ...
... En los procesos de sucesión, la fauna silvestre a través de la dispersión y depredación de semillas, polinización y herbivoría, modifi can su hábitat favoreciendo la reproducción y producción de frutos, regulando las poblaciones de ciertas especies de plantas. Además de estas funciones y procesos, los servicios que la biodiversidad y en especial la fauna ofrece al ser humano, se relacionan con servicios de provisión a través de la producción de miel; servicios de regulación como la dispersión de semillas y polinización, servicios de soporte en la generación de suelo por medio de anélidos e insectos, y servicios culturales por medio de toda la tradición oral y belleza escénica que proveen (Whelan et al., 2008;MADS, 2012;Pla et al., 2012). Por ejemplo, algunas especies de aves realizan procesos de descomposición, polinización, dispersión de semillas y depredación, que se ven refl ejados principalmente en servicios de regulación y provisión (Whelan et al., 2008;Pla et al., 2012). ...
... Además de estas funciones y procesos, los servicios que la biodiversidad y en especial la fauna ofrece al ser humano, se relacionan con servicios de provisión a través de la producción de miel; servicios de regulación como la dispersión de semillas y polinización, servicios de soporte en la generación de suelo por medio de anélidos e insectos, y servicios culturales por medio de toda la tradición oral y belleza escénica que proveen (Whelan et al., 2008;MADS, 2012;Pla et al., 2012). Por ejemplo, algunas especies de aves realizan procesos de descomposición, polinización, dispersión de semillas y depredación, que se ven refl ejados principalmente en servicios de regulación y provisión (Whelan et al., 2008;Pla et al., 2012). ...
Chapter
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En el contexto de cambio climático se esperan alteraciones en las estructuras, funciones y servicios de los ecosistemas de alta montaña. Proyectar cómo y dónde ocurrirán, requiere un estudio espacial y temporal, que puede realizarse por medio de Sistemas de Información Geográfica (SIGs). Con estos sistemas es posible monitorear los efectos y riesgos asociados al cambio climático, y diseñar medidas de adaptación y mitigación.
... Selección de rasgos funcionales. Se seleccionaron los rasgos morfométricos y de historia de vida que proporcionaban más información en términos funcionales y simultáneamente eran de fácil obtención (Pla et al. 2012). Los rasgos morfométricos correspondían a medidas cuantitativas y continuas, mientras que los rasgos de historia de vida eran medidas cualitativas y nominales. ...
... Análisis estadístico. Los grupos ecológicos se identificaron a través de un análisis por conglomerados jerárquicos, utilizando el método de Ward mediante la distancia de cuatro rasgos de historia de vida (dieta, estrategia de forrajeo, hábitat de forrajeo y tamaño), obtenida a partir de la similitud de Jaccard (Pla et al. 2012). El método de Ward produce grupos más diferenciados entre sí, al minimizar la heterogeneidad interna, al mismo tiempo que la aumenta entre los demás conglomerados (Casanoves et al. 2011). ...
Article
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Introducción: En el Caribe colombiano la expansión de sistemas convencionales (SC) de ganadería extensiva ha generado una pérdida masiva de bosque seco tropical (Bs-T). Pese a la implementación de sistemas silvopastoriles (SSP) en esta región, son escasos los estudios que evalúen la incidencia de este tipo de manejo sobre murciélagos. Objetivo: Analizar la variación de rasgos funcionales de grupos ecológicos de murciélagos entre fragmentos de Bs-T inmersos en SC y SSP, pertenecientes a cinco localidades del departamento de Córdoba (Colombia). Metodología: Se usaron ejemplares de colecciónpara identificar grupos ecológicos a partir de rasgos de historia de vida, y luego se compararon rasgosmorfométricos de cada grupo asociados con el tamaño (longitud del antebrazo) y vuelo (longitud del dígito tres y cinco) entre fragmentos de Bs-T inmersos en SC y SSP. Resultados: Se identificaron seis grupos ecológicos. Los rasgos asociados con el tamaño y vuelo fueron significativamente mayores en los SSP para dos de los grupos ecológicos identificados (p<0,05). La matriz en los SSP constituye partedel hábitat para murciélagos, lo cual puede ofrecer mejores condiciones para el desarrollo morfométrico de algunas especies claves en procesos de polinización y dispersión de semillas. Conclusión: Aunque las respuestas funcionales de murciélagos fueron idiosincráticas, el manejo silvopastoril parece ser más sostenible para estos mamíferos. Es importante tener en cuenta el tipo de manejo de sistemas productivos que favorezcan la biodiversidad, porque al dominar en las matrices de los paisajes, son determinantes para el mantenimiento de las especies en escenarios de transformación.
... Our way of defining the PFTs comprises intuitive schemes (such as the most classic one ascribed to Theophrastos) and highly formalised procedures involving complex data-analytical apparatus (e.g. Pla et al., 2012). Although the intuitive schemes (involving a priori defined FCs) have their validity (and show resolution power) in some instances, their usefulness is very much limited to systems with few species. ...
Article
The concepts of traits, plant functional types (PFT), and functional communities are effective tools for the study of complex phenomena such as plant community assembly. Here, we (1) suggest a procedure formalising the classification of response traits to construct a PFT system; (2) integrate the PFT, and species compositional data to formally define functional communities; and, (3) identify environmental drivers that underpin the functional-community patterns. A species–trait data set featuring species pooled from two study sites (Eneabba and Cooljarloo, Western Australia), both supporting kwongan vegetation (sclerophyllous scrub and woodland communities), was subjected to classification to define PFTs. Species of both study sites were replaced with the newly derived PFTs and projected cover abundance-weighted means calculated for every plot. Functional communities were defined by classifications of the abundance-weighted PFT data in the respective sites. Distance-based redundancy analysis (using the abundance-weighted community and environmental data) was used to infer drivers of the functional community patterns for each site. A classification based on trait data assisted in reducing trait-space complexity in the studied vegetation and revealed 26 PFTs shared across the study sites. In total, seven functional communities were identified. We demonstrate a putative functional-community pattern-driving effect of soil-texture (clay—sand) gradients at Eneabba (42% of the total inertia explained) and that of water repellence at Cooljarloo (36%). Synthesis. This paper presents a procedure formalising the classification of multiple response traits leading to the delineation of PFTs and functional communities. This step captures plant responses to stresses and disturbance characteristic of kwongan vegetation, including low nutrient status, water stress, and fire (a landscape-level disturbance factor). Our study is the first to introduce a formal procedure assisting their formal recognition. Our results support the role of short-term abiotic drivers structuring the formation of fine-scale functional community patterns in a complex, species-rich vegetation of Western Australia.
... El impacto humano refleja la antropización que existe en los ambientes (Sanderson et al., 2002), lo que corresponde a un gradiente de modificaciones ocurridas de forma directa o indirecta, donde aquellos paisajes o ambientes que han tenido poca o ninguna influencia del hombre tendrían una antropización nula. Los ambientes con diferentes grados de antropización se alejan de las definiciones rural y urbano que han sido definidos por Aurousseau (1921) como: puede inferir a partir de los rasgos de historia de vida, que son todas aquellas características que interactúan con el ambiente y que tienen un efecto, positivo o negativo, en la adecuación de los individuos (Pla et al., 2012). En este sentido, dichas características se pueden utilizar para estimar la probabilidad de presencia de las especies en ambientes antropizados. ...
... We decided to use FDis, as a proxy of habitat filtering (according to Hedberg et al., 2014). Despite FDis similarly to FDiv informs about dispersion in trait hyperspace, FDis is independent of the convex hull concept, which makes it less sensitive to outliers compared to the other three functional diversity indices (Laliberté and Legendre, 2010;Pla et al., 2012). To explore shifts in species composition of riparian plant communities we used ordination techniques. ...
Article
Riparian zones are among the ecosystems with the highest susceptibility to human impacts, and the main drivers influencing their function are river regulation and urbanization. In this study we aimed to assess shifts in species composition of riparian vegetation over three decades and discuss effects of river regulation (expressed as limitation of episodic flooding) on species and functional diversity of the understory of riparian plant communities in an urban landscape before and after dam building. We compared riparian vegetation in 59 pre-dam plots assigned to four types of riparian vegetation, initially investigated in the years 1970–1984 with 50 post-dam plots, sampled by us in 2011-2018. We explored changes in the importance of competition in shaping plant species composition, using a set of ecological indicator values, plant functional traits and components of functional diversity. Results of the study suggest that river regulation drove compositional shifts in plant communities surveyed, probably caused by displacement of species with strategies allowing occurrence under high stress levels by plants with higher competitive abilities, including ornamental alien species. We revealed increasing magnitudes of compositional shifts along an environmental gradient of riparian vegetation with the largest changes observed in pioneer forest communities. Implementing natural flows with consideration for relationships between plant strategies and their key life-history traits, and aspects of the flow regime, may be a proper tool for restoration and maintenance of riparian vegetation as buffer zones in urban landscapes.
... Estas respuestas diferenciales están directamente relacionadas con plasticidad o capacidad de adaptación de las especies con el grado de modificación ambiental que exista en el ambiente. La plasticidad se puede inferir a partir de los rasgos de historia de vida, que son todas aquellas características que interactúan con el ambiente y que tienen un efecto, positivo o negativo, en la adecuación de los individuos (Pla et al., 2012). En este sentido, dichas características se pueden utilizar para estimar la probabilidad de presencia de las especies en ambientes antropizados. ...
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El proceso de modelado de nichos ecológicos y distribución de especies ha sido producto del desarrollo de la teoría de nicho ecológico y algoritmos que han tratado de reproducir las complejas relaciones que dan origen y forma a las áreas de distribución de las especies. El presente trabajo muestra una estrategia metodológica basada en modelos de nicho ecológico para estimar la adecuabilidad –existencia de condiciones ambientales propicias para una especie– en ambientes antropizados. Dicha estrategia consiste en la combinación de modelos de distribución de especies “tradicionales” con variables climáticas y topográficas y modelos basados en variables asociadas a la antropización. Para combinarlos se generaron reglas de decisión basadas en los atributos funcionales de especies de vertebrados asociados a cuerpos de agua, (un ave (Cinclus mexicanus), un mamífero (Noctilio leporinus), un reptil (Kinosternon integrum) y un anfibio (Hyla eximia)) que indican el grado de tolerancia a los ambientes antropizados. Aunque la combinación de los modelos climático-antropizados representa una simplificación de una realidad, este tipo de aproximaciones pueden dar una idea acerca de cómo se representan las condiciones propicias para una especie en gradientes antropizados. No obstante, deben ponerse a prueba en campo para conocer la precisión de los modelos.
... Functional diversity is usually measured as functional groups or indices. The former are groups are of ecologically similar species and can be defined a priori or a posteriori (Pla et al. 2012). The latter are a value calculated based on the functional traits present in the community. ...
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Functional traits are ecologically relevant characteristics of species. They are relevant to community structuring in face of environmental drivers (response traits) and to ecosystem processes (effect traits). For planktonic microcrustaceans, the link between functional traits and their responses or effects is not always clear. Our objective was to review the literature on linking functional traits to environmental drivers and ecosystem processes for planktonic cladocerans and copepods. Response traits are discussed in four categories: morphological, life history, behavioral, or physiological. Temperature, predation, resources, and stressors are important drivers of morphological and life-history traits. Body size, a morphological trait, is probably the most important trait, because it responds to several environmental characteristics and is correlated with physiological traits and to zooplankton impact on ecosystems functions. In an ecosystem perspective, zooplankton is an important energy link between primary producers and secondary consumers. In trophic webs, it may control phytoplankton biomass and productivity, with consequences for whole lakes. Its influence on carbon, nitrogen, and phosphorus cycles is expected to increase with body size. Other traits may be important, but there is a lack of information. We point out the need of more functional trait research, especially with freshwater copepods and neglected tropical species. For a better understanding of natural systems, an integrative approach of multiple traits with multiple environmental drivers and ecosystem functions is necessary.
... Understanding the underlying mechanism of biodiversity effects on belowground biomass is essential to the preservation of biodiversity and the maintenance of ecosystem services. Leaf traits and wood density are closely linked to carbon and nutrient investment strategies of tree species (Poorter and Bongers 2006), thus are widely used in BEF studies (Pla et al. 2012;Conti and Díaz 2013;Finegan et al. 2015). Through analysis of relevant functional traits, topographic and edaphic variables, coarse-root biomass, fine-root biomass, and fine-root necromass in an old-growth broad-leaved evergreen forest, this study explores the relative predominance of the NC and MR hypotheses in regulating belowground biomass, as well as the predictive power of environmental variables. ...
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The positive effects of biodiversity on aboveground biomass in natural terrestrial ecosystems have been well documented, whereas the relationships between tree biodiversity and belowground biomass remain largely unexplored. Traditionally, two sets of hypotheses based on the functional trait approach, niche complementarity (NC) and mass ratio (MR), have been proposed to explain the positive effects of biodiversity. Whereas NC emphasizes that functional discrepancy enhances the collective functioning of a given ecosystem, MR states that ecosystem functioning is mainly regulated by the functional traits of dominant species. This study explored the relative importance of these two hypotheses and the effects of forest stand and environmental characteristics on belowground biomass in an old-growth broad-leaved evergreen forest. The mean coarse-root biomass, fine-root biomass, and fine-root necromass were 117.78 ± 54.000, 4.09 ± 0.85, and 0.60 ± 0.31 Mg·ha ⁻¹ , respectively. We found positive effects of functional diversity on belowground biomass; however, the community-weighted mean trait values were more relevant, indicating that MR exhibited more explanatory power than NC. The combination of informative environmental factors explained 62.0%, 53.2%, and 37.8% of the variation of coarse-root biomass, fine-root biomass, and fine-root necromass, respectively. Our results suggest that the functional identity of dominant tree species exerts more influence than functional diversity on the belowground biomass in old-growth forest ecosystems and that forest stand characteristics and topographic and edaphic factors also play important roles in shaping belowground biomass patterns in old-growth forest ecosystems.
... We defined the plant consumption traits as: preferred by either gorillas or chimpanzees ("Preferred chimpanzee" and "Preferred gorilla"), preferred by both gorillas and chimpanzees ("Preferred apes"), fallback for either gorillas or chimpanzees ("Fallback chimpanzee" and "Fallback gorilla"), or fallback for both gorillas and chimpanzees ("Fallback apes"). We used Correspondence Analysis (CA) to analyze the multivariate data (Hill, 1974) of species traits, as proposed by Pla, Casanoves, and Rienzo (2012). CA is an indirect gradient ordination based on weighted averaging, which uses the position of the sample to identify that of species (or consumption traits in our case), and vice versa (Lepš & Šmilauer, 2003). ...
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Understanding the mechanisms governing the coexistence of organisms is an important question in ecology, and providing potential solutions contributes to conservation science. In this study, we evaluated the contribution of several mechanisms to the coexistence of two sympatric frugivores, using western lowland gorillas (Gorilla gorilla gorilla) and central chimpanzees (Pan troglodytes troglodytes) in a tropical rainforest of southeast Cameroon as a model system. We collected great ape fecal samples to determine and classify fruit species consumed; we conducted great ape nest surveys to evaluate seasonal patterns of habitat use; and we collected botanical data to investigate the distribution of plant species across habitat types in relation to their “consumption traits” (which indicate whether plants are preferred or fallback for either gorilla, chimpanzee, or both). We found that patterns of habitat use varied seasonally for both gorillas and chimpanzees and that gorilla and chimpanzee preferred and fallback fruits differed. Also, the distribution of plant consumption traits was influenced by habitat type and matched accordingly with the patterns of habitat use by gorillas and chimpanzees. We show that neither habitat selection nor fruit preference alone can explain the coexistence of gorillas and chimpanzees, but that considering together the distribution of plant consumption traits of fruiting woody plants across habitats as well as the pattern of fruit availability may contribute to explaining coexistence. This supports the assumptions of niche theory with dominant and subordinate species in heterogeneous landscapes, whereby a species may prefer nesting in habitats where it is less subject to competitive exclusion and where food availability is higher. To our knowledge, our study is the first to investigate the contribution of plant consumption traits, seasonality, and habitat heterogeneity to enabling the coexistence of two sympatric frugivores. OPEN RESEARCH BADGES This article has earned an Open Data Badge for making publicly available the digitally‐shareable data necessary to reproduce the reported results. The data is available at https://datadryad.org/resource/doi:10.5061/dryad.ms65f29.
... (i.e. mean body size or habitat CV weighted by species abundance) in order to test possible shifts in mean body size and habitat specialization values within coccinellid assemblages driven by urbanization (Pla et al., 2012). Higher CWM.bs means communities dominated by larger individuals and higher CWM.hab means communities dominated by habitat generalist species. ...
Article
Urbanization alters community composition, frequently leading to decline in native species abundance and richness. Nevertheless, responses might also depend on trait-based local habitat and landscape-scale filters. In this work, we studied how local characteristics of greenspaces and landscape context at 100 and 1000 m influence taxonomic and functional traits composition of native and alien coccinellids (Coleoptera: Coccinellidae) across an urbanization gradient extending from the city of Santiago, Chile, into surrounding rural areas. We found that greenspaces supported a rich community of coccinellids, including many native species, but both native and alien species were negatively affected by urbanization. Local habitat variables were not important predictors of coccinellids richness, abundance or functional traits. On the other hand, landscape composition at both scales did affect coccinellid communities in greenspaces. At both landscape scales, there was variation in the association of coccinellids with landscape variables based on their primary diet, thus, urbanization might differentially affect the ecological service provided by different functional groups of coccinellids. Our results show that greenspaces support a rich community of coccinellids, including many native species, but the degree to which greenspaces conserve these communities depends on the level of urbanization.
... It is related to the mass ratio hypothesis, which states that functional traits of dominant species determine ecosystem processes (Grime, 1998), and was calculated as the mean of each functional trait weighted by species' relative abundance. That is, if the mean value of a given trait for all plant species in the community increases, the value of CWM for that trait also increases (Pla et al., 2012). WCV was used as a univariate measure of functional diversity per site and was calculated as the weighted standard deviation divided by the weighted mean. ...
... Although this non-neutral dimension of biodiversity is relatively new, Schleuter et al. (2010), Weiher (2011) and Pla et al. (2012) offer excellent reviews of functional diversity history, concepts, available metrics and guidelines for selecting a proper method. The simplest way to assess functional diversity is to count the number and relative importance of guilds or functional groups. ...
... Although this non-neutral dimension of biodiversity is relatively new, Schleuter et al. (2010), Weiher (2011) and Pla et al. (2012) offer excellent reviews of functional diversity history, concepts, available metrics and guidelines for selecting a proper method. The simplest way to assess functional diversity is to count the number and relative importance of guilds or functional groups. ...
... The community-weighted mean of functional traits (CWM) was also calculated to synthesize changes in mean values of traits within communities associated with changes in environmental conditions. CWM represents the average for each trait weighted by its relative abundance in the community (Pla et al., 2011). Functional diversity measures (FDis and CWM) were performed using R programming version 3.2.2 ...
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Accelerated eutrophication reduces water quality and shifts plankton communities. However, its effects on the aquatic food web and ecosystem functions remain poorly understood. Within this context, functional ecology can provide valuable links relating community traits to ecosystem functioning. In this study, we assessed the effects of eutrophication and cyanobacteria blooms on zooplankton functional diversity in a tropical hypereutrophic lake. Phytoplankton and zooplankton communities and limnological characteristics of a tropical Brazilian Lake (Southeast, Brazil) were monitored monthly from April 2013 to October 2014. Lake eutrophication indicators were total phosphorus, total chlorophyll-a, and chlorophyll-a per group (blue, green, and brown). The variation of major phytoplankton taxonomic group biomass was calculated and used as a proxy for changes in phytoplankton composition. Zooplankton functional diversity was assessed through functional dispersion and the community-weighted mean trait value. Regressions were performed between the lake eutrophication indicators, the phytoplankton biomass variation, and zooplankton functional dispersion. Our results suggest that eutrophication and cyanobacterial dominance change the composition of zooplankton traits and reduce functional dispersion, leading to zooplankton niche overlap. These findings are important because they provide a meaningful view of phytoplankton-zooplankton trophic interactions and contribute to an improved understanding their functional effects on aquatic ecosystems.
... For the Gini-Simpson index, it is commonly recognized that direct usage of the observed relative abundance of species (i.e.,p i ¼ X i =N known as the maximum likelihood estimate (MLE) of p i ) will be statistically biased (particularly for small sample sizes which is usual in practical situations), and the biased-corrected estimator of the Gini-Simpson index is Simpson, 1949;Pielou, 1969;Hurlbert, 1971;Krebs, 1989;Magurran, 2004;Chen, 2015). To this end, evaluating the estimation bias of Rao's quadratic diversity index is of great value for correctly applying it to research of trait-based functional or phylogenetic ecology (Pla, Casanoves & Di Rienzo, 2012;Swenson, 2014;Chen, 2015). ...
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Rao's quadratic diversity index is one of the most widely applied diversity indices in functional and phylogenetic ecology. The standard way of computing Rao's quadratic diversity index for an ecological assemblage with a group of species with varying abundances is to sum the functional or phylogenetic distances between a pair of species in the assemblage, weighted by their relative abundances. Here, using both theoretically derived and observed empirical datasets, we show that this standard calculation routine in practical applications will statistically underestimate the true value, and the bias magnitude is derived accordingly. The underestimation will become worse when the studied ecological community contains more species or the pairwise species distance is large. For species abundance data measured using the number of individuals, we suggest calculating the unbiased Rao's quadratic diversity index.
... (2) functional evenness (FEve), which describes the distribution of abundances in a functional space of traits, where low functional evenness indicates that some parts of the functional niche are being underutilized; (3) functional divergence (FDiv), which is a measure of functional similarity among the dominant species of a community; and (4) functional dispersion (FDis), which is the mean distance of individual species to the centroid of all species in the community (Mason et al. 2005 In the second approach, we classified species into discrete groups in terms of their functional similarities according to traits related to reproduction, trophic flow, and habitat use, to obtain a broad and complementary characterization of the niche partition (Díaz and Cabido 2001;Villéger et al. 2010). Traits with categorical values were converted to dummy variables and, together with the traits in continuous values, similarity among species was calculated with modified Gower distances, which allows categorical and continuous data to be used together (Pla et al. 2012). For the classification of functional groups, we made a regression and classification tree (LINKTREE) of the value of the functional traits for the amphibian species. ...
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Functional diversity is a tool for understanding biological communities and the influence of environmental filters on assembly rules. However, few studies explore the relationships of diversity metrics across contrasting ecosystems. We evaluated the effect of ecosystems (tropical dry forest and pine-oak forest) and seasons (wet and dry) on the functional diversity and community composition of amphibians in western Mexico. Our study showed that associations among metrics of diversity were not constant across contrasting ecosystems. The amphibian communities were related to changes in the environmental variables of elevation, temperature and relative humidity. We analyzed the functional diversity of the amphibian community based on 11 traits related to reproduction, trophic flow and habitat use. Seven functional groups with distinct ecological characteristics were detected, of which, four presented functional redundancy and two were represented by a single species. While the tropical dry forest during the wet season showed the highest species richness, the richness and diversity of functional groups were significantly lower than in the pine-oak forest in both seasons. These results suggest that the seasonal drought in the tropical dry forest could act as an environmental filter, promoting dominance of similar functional traits among species, while limiting similarity could be acting in the pine-oak forest, in the face of relatively stable hydric conditions, allowing a greater functional diversity. Analysis of the relationship between biological communities and ecosystem functioning is necessary to undertake conservation strategies.
... To select groups, we pruned the dendrogram at a level of 50%. Using SPSS (IBM SPSS Statistics for Windows, version 20, IBM Corp., Armonk, NY; Pla et al., 2012) we later performed a factor analysis to validate the grouping made by the cluster analysis. We used the factor scores to plot the functions. ...
Article
Regions with similar environmental determinants are known to produce the independent evolution of similar features in unrelated species. This hypothesis is pervasive in ecology evolution and biogeography. To explore community convergence in trait structure, we compared perennial plant species assemblages in samples of a representative section of two distant and isolated coastal fog deserts of North and South America. These fog deserts are considered equivalent biomes, but there is a paucity of quantitative data to objectively support their similarities. General climate in both deserts showed the same trends, but Atacama exhibited almost no precipitation and had a stronger influence of fog. We found no shared species in our plots and limited phylogenetic relatedness. A two way cluster analysis separated groups of traits in fog deserts from neighboring dry deserts and Mediterranean systems. We found remarkable similarities in functional structure of fog deserts; 65% of the 26 studied functional trait categories showed less than 12% difference in relative cover among them. Three functional plant groups (deciduous, evergreen and succulent–CAM) were well defined when using hierarchical clustering. The deciduous group was dominant in both areas. There was a strong community convergence in vegetation structure, but some traits inevitably differed among deserts. Our results resolved in quantitative terms the similarities among functional traits, and indicated the need to expand the fine scale study of plant trait convergence in fog deserts.
... We calculated them using the PhyloMeasures package (Tsirogiannis and Sandel 2016). We quantified functional diversity by functional richness (FRic), expressing the quantity of plant functional types present in a community and functional dispersion (FDis), expressing the size of community species traits hypervolume within the functional trait space (Mason et al. 2005;Laliberté and Legendre 2010;Pla et al. 2011). These two indices were calculated using the FD package (Laliberté et al. 2014). ...
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Despite good recognition of distributions and spread mechanisms of the three most invasive trees in Europe (Prunus serotina, Quercus rubra and Robinia pseudoacacia), their impacts on forest biodiversity are unevenly recognized. Most studies cover only taxonomic alpha diversity, and only a single study included functional and phylogenetic diversity. Using a set of 186 study plots in western Poland we assessed the impacts of these invasive tree species on the alpha and beta taxonomic, functional and phylo-genetic diversity of understory vascular plants. Alpha diversity was higher in R. pseudoacacia forests and lower in Q. rubra forests compared to mature native forests. Compared to non-invaded plantations and forests, alpha diversity was higher in P. sylvestris plantations invaded by P. serotina, but lower in invaded nutrient-poor P. sylvestris forests. Alien species richness was higher and beta diversity was lower in forests invaded by P. serotina or R. pseudoacacia than in non-invaded forests. In contrast, beta diversity was higher in Q. rubra forests than in native forests. We proved that invaded forests differed from non-invaded forests in species composition, but not always with decreased alpha and beta diversity. Impacts of particular invasive species also depended on the reference ecosystem properties (here mature native forests, which did not always have the highest biodiversity), which is a source of inconsistency in previous studies, usually referring to single native ecosystem types.
... Functional diversity is an increasingly used concept to address changes in biodiversity (Mason et al. 2005). Functional diversity summarises the key properties of ecosystems, and is useful for the evaluation of the effects of land use on the provision of ecosystems services for human wellbeing (Harris et al. 2006;Pla et al. 2011). The definition of functional diversity (from Mason et al. 2005) is the distribution of species and abundance of a community in niche space, including the amount of niche space filled by species in the community (functional richness). ...
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High human population growth and rapid urbanisation, particularly in Africa, have led to an increased interest in the impacts of this land-use change on bird communities. The African Bird Atlas Project, where species presence lists are collected in pentads, is a valuable source of data with which to explore the extent of these impacts. Here, for the first-time, we test for differences in species richness patterns across 50 matched pentad pairs from sub-Saharan Africa classified as either urban (or semi-urban) and rural. We found that species richness was lowest in pentads classified as urban (mean ± SD: 132 ± 59 species), compared with rural (172 ± 54). However, species richness was similar, compared with rural pentads, when levels of urbanisation were maintained at intermediate levels (semi-urban: 141 ± 69). Surprisingly, we found no significant differences in functional diversity measures between any land-use categories. Across most major dietary guilds (carnivores, herbivores, insectivores, granivores) species richness was lower in urbanised pentads and species were often small. However, the overall biomass of these guilds was similar between urbanised and non-urbanised areas, indicating the presence of common urban exploiter species. This resulted in no differences in functional diversity overall. Pollinators and piscivores showed little difference in metrics between rural and urban pentads. According to a model of the functional traits we consider, an African urban exploiter species is best described by being a scavenger, and less likely to be a habitat specialist, but fill a variety of niches. The urban spatial planning implications are that rare and range-restricted species in proximity to cities, as well as large bird species, will require particular attention and conservation measures as African cities continue to expand. Species richness could be maintained with intermediate levels of urban infrastructure development.
... We used Faith's phylogenetic diversity (PD; i.e. sum of phylogenetic tree branch lengths, representing all species present in the community) calculated using the PhyloMeasures package (Tsirogiannis and Sandel, 2016) to reflect phylogenetic alpha diversity. We quantified functional diversity components: functional richness (FRic), expressing quantity of plant functional types present in a community and functional dispersion (FDis), expressing size of community species trait hypervolumes within the functional trait space, functional divergence (FDiv), expressing level of trait convergence/divergence and functional evenness (FEve), expressing distribution of trait values within a community (Mason et al., 2005;Laliberté and Legendre, 2010;Pla et al., 2011). We calculated them using the FD package (Laliberté et al., 2014). ...
Article
Forests are the dominant terrestrial ecosystems on the Earth. During natural succession, a quite known pattern of changes occur (i.e., the process of a gradual assemblage of plant species and associated organisms best adapted to the current habitat conditions). Much less is known about novel ecosystem establishment's primary spontaneous successional mechanisms due to human agency such as post-coal mine heaps habitats. The post-coal mine heaps are sites of pure mineral substrates and constrain (e.g., temperature, acidity, drought, salinity) habitat conditions. These conditions are variable both in time and space. Regardless of all these constraints, diverse vegetation is soon spontaneously developing on these sites. A characteristic feature of the vegetation successional development on post-coal mine heaps is the emergence of non-analogous species assemblages when comparing to the natural and seminatural vegetation communities and ecosystems. This study aimed to compare the forest spontaneously developed on the mineral novel material habitat of the post-coal mining heap, with forests in the surrounding, on non-industrial habitats (located in Silesian Upland (South Poland)) in taxonomic, phylogenetic, and functional diversity at alpha (within-site) and beta (among sites) levels. The functional traits values of the recorded species composition were calculated to assess, e.g., the taxonomic alpha diversity Shannon's diversity and evenness index, Simpson index, functional richness (FRic), functional dispersion (FDis), functional divergence (FDA), and functional evenness (FEve). Rao's entropy has standardized the Biotic Novelty Index (BNI) to reflect the proportion of functional diversity contributed by novel species composition. The results revealed higher functional richness and dispersion in coniferous forests than in forests on heaps. The plots from coniferous forests and heaps were distinctly differentiated in terms of species composition. No difference occurred in functional evenness and divergence. Vegetation patches of coniferous forests had 19% higher species richness and twice higher Faith's phylogenetic diversity, while no differences in species diversity described by Shannon's diversity index have been recorded. An almost thirty times higher biological novelty index in forests on heaps than in coniferous forests patches has been recorded. The RLQ - analysis of relationships between plant traits, species composition and environmental variables revealed significant associations between EIVs and type of habitat and plant traits. The plant traits such as SLA and SM seem indifferent and do not differentiate the two studied habitats. The results showed that both understanding mechanisms by which these habitats are shaped and recognizing their biological potential and values are essential for nature conservation and management and challenge future studies.
... For the analysis of functional traits, we computed the Community Weighted Mean (CWM), which represents the weighted mean trait in a community and accounts for the abundance of the species that carries the considered trait (Pla et al. 2012). The CWM of categorical traits was measured as the relative abundance of the category or group in the community, while the CWM of continuous traits was calculated as the trait average value (Lavorel et al. 2008). ...
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The Formica rufa group comprises several ant species which are collectively referred to as "red wood ants" (hereafter RWA). These species have key roles in forest ecosystems, where they are ecologically dominant and greatly influence the dynamics of the habitat they colonise. Various studies have shown how their trophic activity may affect other organisms, which include both other invertebrates and plants. We can therefore hypothesize that their presence could affect the taxonomic and functional composition of epiphytes, despite clear information on such an effect is lacking. This study aimed to fill this research gap by evaluating whether the presence of red wood ants could affect the structure and composition of lichen communities. We selected two sites on the Apennine Mountains in Italy, where the red wood ant F. para-lugubris was introduced from the Alps more than 50 years ago. In each site, lichen assemblages on Abies alba trees located within the colonised areas were compared to those from nearby, non-occupied areas. The results allowed for the identification of significant effects of F. paralugubris on the structure of lichen communities. Although there was no detectable impact on lichen species richness, a significant difference in their community composition between colonised and control sites was detected. Furthermore, ant presence seemed to be associated with specific lichen functional traits such as asexual reproduction. We argue that RWA could affect the lichen community either directly , e.g., by actively dispersing the species capable of asexual reproduction through their movements on trees (ant-mediated dispersion), or indirectly through herbivore exclusion. Finally, we also observed differences in β-diversity among the colonised and non-colonised sites.
... For mammals, we chose two quantitative and seven qualitative traits linked to resource use and niche dimensions(Table 1)(Sukma et al. 2019). Trait values for each species were provided by experts and obtained from literature (e.g.Campos and Ojeda 1997;Campos et al. 2001;Ojeda and Tabeni 2009;Villagra et al. 2011;Campos and Velez 2015).Functional dispersion for both plants and mammals was calculated as an indicator of functional diversity (hereafter FD) with the species records for each sampled tree combined with trait information(Villéger et al. 2008;Pla et al. 2012;Mason and Mouillot 2013). Functional dispersion ...
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Background The ecological indicators are useful tools to determine the effects of human disturbances on woodland biodiversity. Nevertheless, ecological indicators not always responded in the same way to disturbances, and the responses can differ among taxa. In arid and semiarid woodlands, the use of deadwood associated with cattle raising can affect biodiversity and Nature’s contributions to people. Methods Our study aimed to assess changes in taxonomic and functional diversity of two assemblages, plants and mammals, in Prosopis woodlands under different land management types: grazed woodlands and a protected area. For plants, changes in structural diversity were also analyzed. Prosopis trees under different land management types were selected and their deadwood characteristics were registered. Through live traps and camera traps, we obtained data on the presence-absence of mammals per tree to estimate diversity indices. For plants, we measured the abundance of vegetation by species and by cover type through the Line-Intercept Method to estimated diversity. Finally, we built generalized linear models to assess the responses of diversity of each assemblage to covariables concerning deadwood and different land management types. Results We found that all diversity indeces for plants were either negatively affected by the presence of deadwood on the ground, or favored by its extraction. For mammals, removal of deadwood increased taxonomic diversity, while functional diversity increased with deadwood on the trees. Both structural diversity of plants and functional diversity of mammals were greater in grazed woodlands. Conclusions The sustainable use of woodland resources is essential for the activities of rural communities. Our study results indicated that land management of grazed woodlands promoted the structural diversity of plant assemblages and the functional diversity of mammals. The presence of deadwood negatively affected plant diversity but it increased mammal functional diversity. It is advisable to maintain trees that preserve their wooden structure within the managed areas to promote the functional diversity of mammals, while trees with extraction from standing wood will favor the functional diversity of the plant assemblage. Understanding the effects of human disturbances can contribute to management for the conservation of woodlands diversity and Nature’s contributions to people.
... Functional diversity (FD) can be summarized using indices based on trait values and taxa dominance in the community, that is abundance (Pla et al., 2012). Rao's quadratic diversity index (Q) (Rao, 1982) is one of the most important FD metrics (Mouchet et al., 2010) that has been widely used to measure the effects of anthropogenic activities on the FD of aquatic organisms. ...
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Aim This study aimed at investigating the taxonomic resolutions (TRs) of benthic macroinvertebrates for freshwater assessments in the scope of the functional trait approach (FTA). Location Macroinvertebrate samples were collected in 22 locations within the Paute River Basin (PRB), Ecuador, over three years (2010, 2011 and 2012). Methods Biological traits were allocated as scores to the macroinvertebrate data (at genus level) through fuzzy coding, using published data. The scores of each genus were used to derive scores for the corresponding family. These two sets of scores were standardized and compared, they were similar in 82% of the cases. Functional diversity (FD) was described by the rRao index, which showed no significant differences between coarse (family level) and fine (genus level) TRs. Cluster analyses using the K-means algorithm were performed to determine similarities between both rRao data sets. The WQ cluster number (K) was varied between 2 and 5 to determine a threshold K value (Kth), after which a WQ assessment differed as a function of the TR being used. Results Kth was 3. Family-level identification in the framework of the FTA in the PRB was suitable in detecting changes of macroinvertebrate assemblages (until Kth = 3). Main conclusions The proposed methodology could be implemented in other basins where decision-makers could decide whether the level of functional trait data similarity is sufficient for WQ management purposes and whether the defined Kth is acceptable. The reliability of the key methodological steps was assessed using performance statistics that have rarely been applied to ecological studies. Despite related research performed in other regions, the present study is the first South American attempt to investigate the effects of TR of benthic macroinvertebrates on freshwater bioassessments using functional traits.
... Con la matriz de valores IV se realizó una clasificación jerárquica multivariada para agrupar las parcelas y diferenciar grupos o tipos de estructuras forestales similares. La clasificación jerárquica multivariada utilizó la distancia de Gower, y sobre esta distancia se aplicó el método de Ward como medida aglomerativa (Pla et al. 2012). De esta manera se obtiene un dendrograma y los valores de IV por especie en cada grupo. ...
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Forests structure of palo santo (Gonopterodendron sarmientoi): Regional assessment for forest management and conservation in Argentine. Gonopterodendron sarmientoi is a threatened native tree of the Dry Chaco region in South America, adapted to semiarid conditions. However, the relationships among climatic and edaphic conditions and its forest structure have not been defined yet. Up to date, in Argentina, the study of palo santo forest management and conservation is scarce and still depends on basic information. The objectives of this study were 1) to classify forest groups based on forest stand a�ributes and species composition, 2) to analyze relationships between dasometric parameters of palo santo with climatic and edaphic variables at the regional level and forest types, and 3) to compare total aboveground biomass between forest types as a tool for managing and conserving this species. We compiled forest inventories carried out during the years 2004-2019, containing dasometric data of palo santo for the northern part of the Argentine Dry Chaco region. In the study area, we extracted climatic and edaphic conditions from global data base and national maps. We obtained three forest groups: palosantal, forests with low presence of palo santo and forests with high presence of palo santo. Temperature, precipitation, evapotranspiration and soil textures had significant effects on the forest structure of palo santo at the regional level and on forest types. The total density of individuals of G. sarmientoi has a different effect on the total biomass depending on the type of forest, which allows for different management and conservation practices. Consolidating a national forest plan for palo santo could address more viable proposals to manage and conserve the species in the region.
... Aspects such as decomposition, and organic matter and nutrient consumption dynamics of soil 472 microorganisms, and nutrient retention see a more substantial influence by dominant plants' 473 differences in functional traits (such as leaf chemistry, or phenology) than by species diversity in the 474 plants present (Hooper et al. 2005). The dominant species are the most critical determinants of 475 ecosystems' properties, such as productivity, carbon sequestration, nutrient cycling, and litter quality, 476 among others (Pla et al. 2012). 477 ...
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When fruit bats forage, they serve an important ecological function, as is seed dispersal. Although several authors have approached the significance of bats in generating ecosystem services, there is a gap in understanding the importance of the seed dispersal by fruit bats for ecosystems and society. To fill this gap, we considered different components, such as ecosystem services drivers, functional ecosystem services, structural ecosystem services, and ecosystem services to humans. By taking two agroecosystems from the Colombian Andean region (mixed crops and extensive livestock) as the study cases, the following methodological approach was applied: i) sampling of frugivorous bats (Driver) present in the agroecosystems; ii) identification of plants dispersed by bats (Functional ecosystem services) in each agroecosystem; iii) identification of the uses given to the plants spread (ecosystem services to humans). Finally, the plants spread by bats were considered as drivers for soil fertility as well. In this line, this research is the first in proposing a ‘causality chain approach’ regarding the generation of ecosystem services by focusing on bat-dispersed plants. The research highlights that the diversity in frugivorous bats, the plants spread by bats, and the number of uses made of these plants were higher in mixed crops.
... Multi-trait functional diversity indices were computed after standardization of trait values, while a single functional trait index was calculated without standardization. Standardization was performed due to observed difference in several orders of studied traits magnitude and scale of measurement (Pla et al. 2012). ...
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Background Regarding the most important ecological challenges, scientists are increasingly debating the relationship between biodiversity and ecosystem function. Despite this, several experimental and theoretical researches have shown inconsistencies in biodiversity and ecosystem function relationships, supporting either the niche complementarity or selection effect hypothesis. The relationship between species diversity, functional diversity, and aboveground biomass carbon was investigated in this study employing standing aboveground carbon (AGC) stock as a proxy measure for ecosystem function. We hypothesized that (i) effects of diversity on AGC can be transmitted through functional diversity and functional dominance; (ii) effects of diversity on AGC would be greater for functional dominance than functional diversity; and (iii) effects of functional diversity and functional dominance on carbon stock varied with metrics and functional traits. Community-weighted means (CWM) of functional traits (wood density, specific leaf area, and maximum plant height) were calculated to assess functional dominance (selection effects). As for functional diversity (complementarity effects), multi-trait functional diversity (selection effects) indices were computed. We tested the first hypothesis using structural equation modeling. For the second hypothesis, the effects of environmental variables such as slope, aspect, and elevation were tested first, and separate linear mixed-effects models were fitted afterward for functional diversity, functional dominance, and the two together. Results Results revealed that slope had a significant effect on aboveground carbon storage. Functional diversity and functional dominance were significant predictors of the aboveground carbon storage (22.4%) in the dry evergreen Afromontane forest. The effects of species richness on aboveground carbon storage were mediated by functional diversity and functional dominance of species. This shows that both the selection effects and the niche complementarity are important for aboveground carbon storage prediction. However, the functional diversity effects (niche complementarity) were greater than functional dominance effects (selection effects). Conclusions Linking diversity and biodiversity components to aboveground carbon provides better insights into the mechanisms that explain variation in aboveground carbon storage in natural forests, which may help improve the prediction of ecosystem functions.
... Se utilizó la distancia de Gower para como métrica para comparar la similitud entre especies y sus rasgos funcionales. Esta distancia permite la combinación de variables cuantitativas y cualitativas presentes en la matriz de similitud (Pla et al. 2012). ...
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Ciclo de carbono en biomasa de bosque con relación al régimen de disturbios en el Chaco seco argentino TESIS PRESENTADA COMO REQUISITO PARA OBTENER EL GRADO DE DOCTOR EN CIENCIAS Y TECNOLOGÍAS FORESTALES por Dante Ernesto Loto Licenciado en Ciencias Biológicas.
... The correlogram allows evaluating autocorrelation levels as a function of spatial distance and provides a description of the level of spatial dependence in the data. The significance level of CWM is the average of functional traits weighted by their relative abundances in the community, representing the zooplankton functional composition in each area (Pla et al. 2011).The CWM values range between 0 (absence of some trait in the community) and 1 (present across all community members). FDQ and CWM indices were calculated by dbFD function (Laliberté & Legendre 2010;Laliberté et al. 2014) in R program version 3.2.2 ...
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Mining is an important economic activity that can have severe impacts on aquatic ecosystems. Plankton communities are commonly used as bioindicators of human‐related threats to freshwater environments due to their rapid response to environmental conditions changes. Here, we used zooplankton functional diversity to understand the recovery patterns of an Amazonian lake impacted by mining activity (input of bauxite tailings) after 30 years of natural attenuation and active restoration processes. Zooplankton species richness and functional diversity (Rao's quadratic entropy ‐ FDQ and Community‐level weighted means of trait values ‐ CWM) were compared in impacted and reference areas during the flood period, in March 2015. We found a significant negative influence of turbidity on zooplankton FDQ, and similar FDQ and CWM values between active restoration area and the reference area. These results suggest a positive effect of vegetation restoration efforts for the zooplankton community of Batata Lake. We demonstrated the utility of zooplankton functional diversity metrics as bioindicators of freshwater restoration, the response of the aquatic ecosystem to vegetation restoration and, consequently, water quality. This article is protected by copyright. All rights reserved.
... The highest values were observed for natural regeneration (Fig. 4). This result may be related to the greater diversity of functional characteristics in the composition of regenerating species (De Bello et al., 2013), such as the presence of species of different habits, dispersion modes, and successional classification in the initial recruitment stage, resulting in a larger species pool (Pla et al., 2012;Marcilio-Silva et al., 2016). In addition, the highest values of diversity indicate that the strategies of competing species are evenly distributed in relation to the use of resources in the areas (Sanaphre-Villanueva et al., 2016). ...
... To estimate FD, we followed the conceptual framework provided by Pla et al. (2012), which considers trait values and species importance in the community (i.e. abundance). ...
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We assessed the variation of both composition and functional diversity of mammals along an elevation gradient (1600-3600 masl) at the Tabaconas Namballe National Sanctuary (TNNS) in northern Peru. Using a camera-trap design (85 stations, 8,825 camera days, ~ 317 km 2), we recorded a total of 33 mammalian species during the dry season of 2016. Species-specific effects of environmental covariates based on multi-species occupancy modeling showed that only elevation had a statistically significant effect on occupancy. Also, a principal coordinate analysis and a distance-based redundancy analysis suggested that the variation in species composition is mainly explained by elevation, and moderately by both the normalized difference vegetation index (NDVI) and the distance to roads. The highlands appear to be dominated by a reduced assembly of species consisting of the montane guinea pig, the Andean fox, and the northern pudu. Functional diversity decreased with elevation, providing evidence that lowland and highland communities are functionally dissimilar. Moreover, land-use is changing rapidly in the areas surrounding the TNNS, suggesting that increased connectivity at the two extremes of the elevational gradient (the highlands and the lowlands) will ensure the long-term viability of terrestrial mammalian populations and, thus, the ecological processes in which they are involved.
... La diversidad de especies y su abundancia han sido los parámetros más utilizados para describir la composición de una comunidad vegetal (Moreno et al. 2011). Otros estudios resaltan el valor de los rasgos funcionales como un componente de la diversidad (Saldaña-Acosta et al. 2008, Poorter 2009, Pohl et al. 2011, Lohbeck et al. 2013, Adler et al. 2014, Susan-Tepetlan et al. 2015, Gould et al. 2016, Montes-Pulido et al. 2017, ya que son caracteres cuantificables que reflejan estrategias adaptativas de las especies y son útiles para entender las interacciones entre éstas y su ambiente (Grime 1974, Pla et al. 2012, Mason & de Bello 2013. Por ejemplo, en sitios sometidos a estrés ambiental, como el bosque seco, las especies que se establecen muestran mayor variación en los rasgos funcionales presentando adaptaciones asociadas con la intensidad lumínica (Saldaña-Acosta et al. 2008, Poorter 2009, Lohbeck et al. 2013, Susan-Tepetlan et al. 2015, Montes-Pulido et al. 2017. ...
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Antecedentes: Los rasgos funcionales de las plantas se relacionan con estrategias adaptativas y forman parte de la diversidad biológica. Por su diversidad de adaptaciones las orquídeas terrestres son un modelo para estudiar las relaciones entre su diversidad, rasgos funcionales y ambiente, pero esto ha sido poco estudiado. Preguntas: ¿Cómo cambia la diversidad de orquídeas y sus rasgos funcionales entre tipos de vegetación? ¿Sus rasgos funcionales permiten reconocer grupos de especies? ¿Su diversidad y rasgos funcionales se asocian con variables climáticas y de estructura de la vegetación? Sitio y años de estudio: Reserva de la Biosfera El Cielo, enero 2016-enero 2017. Métodos: Se registró la riqueza, abundancia y rasgos funcionales de orquídeas terrestres, variables climáticas y de estructura vegetal en tres tipos de vegetación. Se estimó diversidad verdadera, recambio de especies y diversidad de rasgos en cada tipo de vegetación, para reconocer grupos funcionales a nivel interespecífico. La diversidad y rasgos funcionales entre tipos de vegetación se asoció con variables ambientales medidas. Resultados: Los bosques de pino-encino y mesófilo de montaña presentaron mayor diversidad verdadera y tuvieron entre si mayor recambio de especies que con el bosque tropical subcaducifolio, éste tuvo la mayor diversidad de rasgos funcionales. Se reconocieron tres grupos funcionales; la diversidad verdadera y funcional se relacionó con temperatura, humedad y densidad del dosel. Conclusiones: La diversidad verdadera no determina la diversidad funcional; ambientes sometidos a mayor estrés ambiental presentan mayor diversidad funcional. La composición de grupos funcionales entre orquídeas estudiadas refleja eventos de convergencia en sus rasgos funcionales.
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In lowland streams, channelization is a severe hydromorphological modification with negative impacts on ecosystem functioning and biological communities. We assessed the functional structure and spatial patterns of macrophyte assemblages in channelized streams, and we identified the most affected traits by this practice. We studied unchannelized (UCS) and channelized sites (CS) using a null model approach and functional diversity indices. The macrophyte coverage was higher in the UCS (mean: 86 ± 15 %) than in the CS (50 ± 35%). Unchannelized sites revealed a random pattern, with predominating submerged and free-floating species, as well as reproduction by turions and tubers. Channelized sites showed a segregation pattern (C-score obs.: 23.08; C- core exp.: 22.20; SES: 3.20) of functionally similar species indicating interspecific competition, and lower functional richness, evenness, and Rao quadratic entropy compared to the UCS. The predominant traits found for macrophyte assemblages of these sites were emergent life form, and dispersion by stolons. Our results indicate that in CS, the abiotic environment and biotic interactions act as filters and only macrophyte species with key traits can colonize these streams. In this sense, the creation of backwater areas, the reestablishment of longitudinal and lateral connections of the streams, as well as macrophyte transplants could favor the dispersal and establishment of macrophyte species. These rehabilitation measures could positively improve the functionality of these ecosystems.
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Chironomid (Diptera: Chironomidae) larvae play an important role in a wide range of aquatic ecosystems. The study focuses on Chironomidae trophic guilds and morphological types as indicator traits in reconstructions of habitat changes in shallow water bodies. Mentum and ventromental plates are important mouthparts whose shape depends on food type and feeding behavior. Chironomidae larvae strongly vary in the mode of life and feeding habits, representing almost every feeding group. Here we classified the mentum types into 16 groups and tested if they indicated similar past habitat changes as the Chironomidae functional feeding groups (FFGs), and tribes/subfamilies. Paleoecological data of biotic and abiotic proxies were derived from short sequences from a Late Glacial oxbow and a nearby medieval moat located in Central Poland. The study revealed that the habitat substratum structure, vegetation and physicochemical conditions are associated both with the feeding types and morphological traits. This provides a valuable tool for future reconstructions of habitat changes.
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Trait-based ecology strives to better understand how species, through their bio-ecological traits, respond to environmental changes, and influence ecosystem functioning. Identifying which traits are most responsive to environmental changes can provide insight for understanding community structuring and developing sustainable management practices. However, misinterpretations are possible, because standard statistical methods (e.g., principal component analysis and linear regression) for identifying and ranking the responses of different traits to environmental changes ignore interspecific differences. Here, using both artificial data and real-world examples from marine fish communities, we show how considering species-specific responses can lead to drastically different results than standard community-level methods. By demonstrating the potential impacts of interspecific differences on trait dynamics, we illuminate a major, yet rarely discussed issue, highlighting how analytical misinterpretations can confound our basic understanding of trait responses, which could have important consequences for biodiversity conservation.
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In the Palaearctic steppe zone, overgrazing was identified as one of the key drivers of declining grassland biodiversity, which underlines the necessity of the functional evaluation of increased grazing pressure on grassland vegetation. We tested the following hypotheses: (a) The effect of grazing intensity on species and functional diversity is strongly dependent on grassland type. (b) The magnitude of diet selectivity of grazers decreases with increasing grazing intensity. (c) Increasing grazing intensity increases evenness and functional evenness of the subjected grasslands. We analyzed vegetation patterns in four types of grasslands (Dry alkali short‐grass steppes, Dry loess steppes, Non‐alkali wet and Alkali wet grasslands) along an intensity gradient of beef cattle grazing at 73 sites in Hungary. Species richness, Shannon diversity, evenness, and four leaf traits were analyzed. We calculated community‐weighted means for each single trait, and multi‐trait functional richness, functional evenness, and divergence for all leaf traits. All species and functional diversity metrics were significantly affected by the grassland type, except leaf dry matter content. The effect of interaction between grazing intensity and grassland type was also significant for functional richness, functional evenness, community‐weighted means of leaf area, and for species richness and evenness. An upward trend of specific leaf area was detected in all grasslands with the highest scores for the overgrazed sites, but the change was also grassland type dependent. The detected trend suggests that with increased intensity the overall selectivity of grazing decreased. We found that evenness was affected but functional evenness was not affected by grazing intensity. Functional evenness scores were more related to the grassland type than to changes in grazing intensity, and displayed a high variability. We stress that one‐size‐fits‐all strategies cannot be recommended and actions should be fine‐tuned at least at the level of grassland type. Our results clearly indicated that the effects of grazing intensity are strongly grassland type dependent. This implies that management strategies and decisions should be fine‐tuned at least at the level of grassland type.
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Plant functional traits regulate ecosystem functions but little is known about how co‐occurring gradients of land use and edaphic conditions influence their expression. We test how gradients of logging disturbance and soil properties relate to community‐weighted mean traits in logged and old‐growth tropical forests in Borneo. We studied 32 physical, chemical and physiological traits from 284 tree species in eight 1 ha plots and measured long‐term soil nutrient supplies and plant‐available nutrients. Logged plots had greater values for traits that drive carbon capture and growth, whilst old‐growth forests had greater values for structural and persistence traits. Although disturbance was the primary driver of trait expression, soil nutrients explained a statistically independent axis of variation linked to leaf size and nutrient concentration. Soil characteristics influenced trait expression via nutrient availability, nutrient pools, and pH. Our finding, that traits have dissimilar responses to land use and soil resource availability, provides robust evidence for the need to consider the abiotic context of logging when predicting plant functional diversity across human‐modified tropical forests. The detection of two independent axes was facilitated by the measurement of many more functional traits than have been examined in previous studies.
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تنوع عملکرد بطور مستقیم در ارتباط با خدمات اکوسیستمی می‌باشد که زیتوده گیاهی بسیاری از خدمات اکوسیستمی از قبیل تامین غذا، حفاظت، گردشگری، گرده افشانی را شامل می‌گردد. در این مطالعه اقدام به آزمون دو فرض اساسی (1) آزمون وجود رابطه نزدیک بین شاخص میانگین وزنی جامعه (CWM) با زیتوده گیاهی، مطابق با نظریه نسبت جرم (2) آزمون وجود رابطه نزدیک بین تنوع عملکرد رائو (Rao) با زیتوده گیاهی، مطابق با نظریه تنوع توسط تیلمان در پیش بینی زیتوده گیاهی و تعیین مناسبترین روابط بین زیتوده گیاهی با عوامل محیطی و شاخص‌های تنوع عملکرد در مراتع مشجر زاگرس مرکزی گردید. نتایج مطالعه نشان داد از بین ارزش ویژگی‌های شاخص CMW، بیشترین مقدار ضریب تبیین (R2) مربوط به شاخص تنوع عملکرد میانگین وزنی شاخص سطح برگ CWM-LAI بود که در حدود 37 درصد بود. همچنین، مقدار این ضریب در شاخص تنوع عملکرد رائو حدود 18 درصد بود که نشان دهنده توجیه 18 درصد تغییرات توسط زیتوده گیاهی می‌باشد. اکثر شاخصهای میانگین وزنی روند افزایشی با افزایش زیتوده گیاهی داشتند. تلفیق فاکتورهای غیرزنده، شاخص تنوع عملکرد رائو و میانگین وزنی جامعه (CWM) شامل متغیرهای بارش، درجه حرارت، میانگین وزنی انرژی متابولیسمی گیاهی، میانگین وزنی طول دوره رشد برگ و ارتفاع و شاخص تنوع عملکرد رائو در حدود 76 درصد تغییرات زیتوده گیاهی را توجیه می‌کنند. با توجه به اینکه شاخص میانیگن وزنی نشان دهنده اثرات گروههای عملکردی چیره بر تولید اکوسیستم است نتایج نشان می‌دهد که فرضیه نسبت جرم گرایم فرضیه صحیح تری در مقابل فرضیه استفاده تکمیلی از آشیان اکولوژیک در تاثیر تنوع عملکرد بر خصوصیات اکوسیتمی مناطق مورد بررسی است.
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Functional diversity and species diversity provide information to understand differences between plant communities from a contrasting environment and the complementary on regional scale. Environmental variation determines which plants can persist in the community via species sorting processes; forest exposed to extended inundation each year has shown divergence in plant community composition, structure, and functional diversity, compared with unflooded dense forest. Here, we researched flooded and unflooded forests in the upper Magdalena River Valley (Colombia) to quantify and compare the plant species diversity and plant functional diversity. We calculated three components of functional diversity (i.e., functional richness, functional evenness, and functional divergence), we also used a measure of functional richness weighted by species abundance. Our results show that the plant community in the unflooded forest has higher stem density and lower basal area than flooded forests. Also, we show that tree communities in the flooded forests had higher specific leaf area, but lower wood density, suggesting an acquisitive resource strategy. Species diversity and functional diversity were higher in the plant community from the unflooded forest. Our findings of the functional traits and the functional diversity components reinforce the idea that the variation between flooded and unflooded forests is going beyond the species list in the plant communities. However, it is still unclear whether any general patterns exist regarding differences between flooded and unflooded tropical forests.
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“Phylogenetic diversity” and its abbreviation “PD” have now become popular terms describing a fundamental aspect of biodiversity based on phylogeny. After more than 25 years of work on PD (following the 1992 paper in Biological Conservation), methods and applications have explored a wide range of taxonomic groups and geographic scales. PD provides a way to address biodiversity at the level of features or characteristics of species, based on its well-corroborated model linking phylogeny and feature variation. The quantification of feature diversity justifies PD as a measure of option value – the value of living variation in keeping options open for society. This justification for PD in biodiversity conservation gives attention to often-neglected arguments for the value to society of biotic diversity. These largely global option values are complemented by the “insurance” value of PD at the local ecosystem scale. Microbial applications of PD, particularly in human health studies, have successfully implemented a range of PD calculations, including PD dissimilarities among samples. Reduced microbial PD in the human body may indicate reduced resilience, and it is now associated with many human diseases. “Macrobial” ecology has been less successful in integrating PD into a consistent coherent approach. Here, the traditional recognition of many “diversity” indices has been extended to phylogeny. PD as a “biodiversity” measure is confounded with the multitude of phylogeny-based diversity indices describing various ecological factors. Greater integration among the different areas of PD application could better establish PD as a core biodiversity measure, with a shared toolbox providing a range of PD-related calculations.
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The study of functional diversity, or the range of species’ ecological roles in a community, is a rapidly expanding area in ecology. Given the extent that ecosystems are being altered, effort should shift towards assessing variation in functional diversity across landscapes with the goal of improve land use management decisions. We construct a workflow that creates three‐dimensional surfaces and maps of functional diversity to examine changes in beetle functional diversity across an Indiana, USA landscape. We sampled 105 prey wood‐borer and predator beetle species along a gradient of forest fragmentation across Indiana and used a number of functional traits from literature sources to capture their functional roles. We developed newly measured functional traits to estimate several traits relevant to beetles’ ecological function that were unknown and not easily measured. Functional diversity indices (FRic, FDis, FDiv, and FEve) were calculated from species abundance and functional traits and used to assess changes in functional diversity along the fragmentation gradient. We predicted that habitat fragmentation would have a greater negative impact on predator beetle functional diversity than prey wood‐borer functional diversity. Landscape metrics most important to the functional diversity of both wood‐borer and predator beetle communities were landscape division index (LDI, an assessment of landscape subdivision) and mean shape index (MSI, a measure of patch shape complexity). Overall, three dimensional surfaces of functional diversity and functional diversity maps across the Indiana landscape revealed that beetle functional diversity was greatest with minimal landscape subdivision. Opposite to what we predicted, we found that the prey wood‐borer functional diversity was more negatively impacted by LDI than the predator beetle functional diversity. Furthermore, predator beetle functional diversity was greater with increasing MSI. The map predicted predator FRic to be highest in forested areas with intact habitat and also less sensitive to habitat fragmentation adjacent to more continuous forest. We propose that land management may be guided by revealing landscapes that are most appropriate for maximizing functional diversity of multiple communities or shifting the relative abundance within prey and beneficial predator beetle functional groups with the use of three‐dimensional plots or maps. This article is protected by copyright. All rights reserved.
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The functional diversity of echinoderms has been understudied, even though these organisms are critical components of various ecosystems, including coral reefs and hard-bottom benthic communities. Additionally, there are only a few papers relating the protection level of marine protected areas (MPAs) with functional diversity. In this study, we calculate the functional diversity of echinoids and asteroids in 11 coral and rocky reefs with different protection levels across the Mexican Pacific. We recorded the abundance of 15 echinoderm species comprising seven echinoid and eight asteroid species. More than 30 morphological and ecological traits of the censused species were evaluated to calculate two functional diversity indices: Rao’s quadratic entropy index (FDQ) and functional richness (FRic). Latitudinal patterns of functional diversity differed between groups. Asteroids showed the highest FDQ and FRic values in the Gulf of California. Echinoids showed FDQ peaks at the highest (Bahía de los Ángeles; 28° 56′, − 113° 30′), and the lowest latitude (Bahías de Huatulco; 15° 43′, − 98° 08′) sites. The Ixtapa-Zihuatanejo site (17° 39′, − 101° 36′) had the highest FRic values. Generalized linear mixed models showed that protection level did not have any significant effect on FDQ or FRic. Latitude, on the other hand, did have a significant effect on asteroid functional diversity, although no significant effects were found for echinoids. The lack of an effect of protection level, and the support of a latitudinal gradient in terms of both taxonomic and functional diversity, has important implications for conservation efforts, supporting the idea of a protected area network to maintain adequate regional biodiversity.
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The impact of veterinary medical products (VMPs) on dung beetles has been thoroughly investigated. However, less is known about the ecological consequences for the ecosystem processes performed by this fauna, especially in relation to functional diversity. We explored the impacts of the long-term use of VMPs on dung beetles from a functional standpoint. We compared two areas with a different kinds of pasture management (long-standing use of VMPs vs. no use of VMPs) over two seasons (autumn and spring). We analyzed the impacts of VMPs on dung beetle functional diversity (using 23 traits) and the ecological process of dung removal. We also examined the relationships between species richness and functional diversity indices. Moreover, we investigated which community attribute was the most important in terms of efficiently sustaining the ecological process of dung removal. Long-standing use of VMPs led to a loss of functional richness, but other functional indices were less affected. A strong correlation between functional richness and species richness showed a low level of dung beetle redundancy, suggesting a low level of resilience in the ecosystem under study. The impact of the long term use of VMPs on dung beetle community attributes in turn had negative effects on the ecological process under study, with a reduction in dung removal capacity of 70%. Interestingly, this ecological process was not driven by functional diversity as many studies have shown, but rather by functional identity, such as the richness in paracoprids, telecoprids and the biomass of large dung beetles. These results raise concerns because large dung beetles, paracoprid and telecoprid beetles are the most functionally efficient in terms of dung removal capacity. At the same time, they are the most vulnerable and the most prone to extinction. Hence, our findings underscore the need to closely restrict the use of VMPs in order to maintain viable and ecologically efficient dung beetle communities.
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Functional diversity is an important component of biodiversity, yet in comparison to taxonomic diversity, methods of quantifying functional diversity are less well developed. Here, we propose a means for quantifying functional diversity that may be particularly useful for determining how functional diversity is related to ecosystem functioning. This measure of functional diversity ''FD'' is defined as the total branch length of a functional dendrogram. Various characteristics of FD make it preferable to other measures of functional diversity, such as the number of functional groups in a community. Simulating species' trait values illustrates how the relative importance of richness and composition for FD depends on the effective dimensionality of the trait space in which species separate. Fewer dimensions increase the importance of community composition and functional redundancy. More dimensions increase the importance of species richness and decreases functional redundancy. Clumping of species in trait space increases the relative importance of community composition. Five natural communities show remarkably similar relationships between FD and species richness.
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Functional diversity has been seen as the key to predicting the stability, invasibility, resource capture, nutrient cycling and productivity of communities. However, it has been unclear how to estimate it. Ten criteria for an index of functional diversity are developed. These include that it should reflect the range of characters present and the abundance of the species with those characters in the community, and be unaffected by the measurement units used or by the number of species. An index that meets all ten criteria, FD var , is investigated. It is based on the variance in characters, weighted by the abundance of the species with those characters. Tested with artificial and randomly generated data, it showed reasonable use of the 0-1 range (mean 0.60, range 0.0009-0.975) and intuitive behaviour. Tested with field data from eight sites in New Zealand, it gave a good spread of values (mean 0.65, range across sites 0.34-0.84), showed good ability to distinguish between the communities and its performance was ecologically intuitive. Illustrative correlations are made with mean annual temperature and soil fertility, determined by a bio-assay. FD var is recommended for general use.
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The convex hull of a set of points is the smallest convex set that contains the points. This article presents a practical convex hull algorithm that combines the two-dimensional Quickhull Algorithm with the general-dimension Beneath-Beyond Algorithm. It is similar to the randomized, incremental algorithms for convex hull and Delaunay triangulation. We provide empirical evidence that the algorithm runs faster when the input contains nonextreme points and that it uses less memory. Computational geometry algorithms have traditionally assumed that input sets are well behaved. When an algorithm is implemented with floating-point arithmetic, this assumption can lead to serious errors. We briefly describe a solution to this problem when computing the convex hull in two, three, or four dimensions. The output is a set of "thick" facets that contain all possible exact convex hulls of the input. A variation is effective in five or more dimensions.
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Functional diversity is a component of biodiversity that generally concerns the range of things that organisms do in communities and ecosystems. Here, we review how functional diversity can explain and predict the impact of organisms on ecosystems and thereby provide a mechanistic link between the two. Critical points in developing predictive measures of functional diversity are the choice of functional traits with which organisms are distinguished, how the diversity of that trait information is summarized into a measure of functional diversity, and that the measures of functional diversity are validated through quantitative analyses and experimental tests. There is a vast amount of trait information available for plant species and a substantial amount for animals. Choosing which traits to include in a particular measure of functional diversity will depend on the specific aims of a particular study. Quantitative methods for choosing traits and for assigning weighting to traits are being developed, but need much more work before we can be confident about trait choice. The number of ways of measuring functional diversity is growing rapidly. We divide them into four main groups. The first, the number of functional groups or types, has significant problems and researchers are more frequently using measures that do not require species to be grouped. Of these, some measure diversity by summarizing distances between species in trait space, some by estimating the size of the dendrogram required to describe the difference, and some include information about species abundances. We show some new and important differences between these, as well as what they indicate about the responses of assemblages to loss of individuals. There is good experimental and analytical evidence that functional diversity can provide a link between organisms and ecosystems but greater validation of measures is required. We suggest that non-significant results have a range of alternate explanations that do not necessarily contradict positive effects of functional diversity. Finally, we suggest areas for development of techniques used to measure functional diversity, highlight some exciting questions that are being addressed using ideas about functional diversity, and suggest some directions for novel research.
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Patterns and changes in functional diversity can inform about spatial and temporal variation in trait diversity, about the processes that drive assembly, and whether assemblages are likely to contain redundant species. We recently provided a new measure (termed FD) and detailed its advantages over previous ones. Since then an increasing amount of research effort has been directed towards both developing appropriate measures of functional diversity and critiquing previous ones, including FD. Podani and Schmera (2006) attempt to do both, though here we argue that they accomplish neither. First, they suggest that a particular distance measure and clustering method are appropriate. We suggest that this is not the case, and show that they may have little effect on quantitative patterns in FD. Second, they suggest that values of functional diversity must be insensitive to the number of functional traits used. We do not agree because we can envisage no relevant ecological question. Third, they observe that we originally defined an FD of zero for an empty assemblage, whereas it is more appropriate for single species assemblages to have FD of zero. We agree. Their solution, however, is to create a measure of functional diversity which violates set monotonicity. Our solution is a revised version of FD for which single species assemblages have FD0, and which does not violate set monotonicity. In conclusion, we are confident that FD behaves appropriately and note that it remains the measure of functional diversity with greatest power to explain variation in ecosystem functioning.
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Fire ecology has been hindered by the lack of comparable, affordable protocols to quantify the flammability of whole plants over large numbers of species. We describe a low-tech device that can be carried to the field and that allows highly standardized measurement of the flammability of whole individuals or portions up to 70 cm long. We illustrate its potential with results for 34 species belonging to different growth forms from central Argentina. The device consists of an 85 × 60 cm half-cut metallic barrel placed horizontally and mounted on a removable metallic structure. It contains three parallel burners, a grill with an attached gauging thermometer and a blowtorch. Burners and blowtorch are connected to a propane–butane gas cylinder. Plant samples are placed on the grill and preheated with the burners for 2 min at 150°C. They are then ignited for 10 s with the blowtorch while the burners are kept on. Four parameters are measured for each sample: maximum temperature reached, burning time, burnt length and burnt biomass percentage. These parameters are used to construct a compound index of flammability for each sample that ranges between 0 (no flammability) and around 3 (maximum flammability). We obtained a wide range of values for flammability and all its components. Most of this variability was accounted for by differences between growth forms and species, rather than by differences at the level of replicates. This suggests that the device and protocol are sensitive enough to detect flammability differences among plants with different functional traits, and at the same time robust enough to produce consistent results among samples with similar traits. A major advantage is that plant architecture is kept almost intact, providing a flammability measure much closer to that of whole individuals in the field than those obtained by other standard protocols in use. The device and protocol presented here should facilitate the acquisition of comparable flammability data over large numbers of species from different floras and ecosystems, potentially contributing to several fields of research, such as functional ecology, evolutionary ecology and vegetation-atmosphere modelling.
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Functional diversity is hypothesised as being beneficial for ecosystem functions, such as productivity and resistance to invasion. However, a precise definition of functional diversity, and hence a framework for its quantification, have proved elusive. We present a definition based on the analogy of the components of species diversity – richness, evenness and divergence. These concepts are applied to functional characters to give three components of functional diversity – functional richness, functional evenness and functional divergence. We demonstrate how each of these components may be calculated. It is hoped that our definition of functional diversity and its components will aid in elucidation of the mechanisms behind diversity/ecosystem-function relationships.
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