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Naturalisation of Ranunculus repens in Kashmir Himalaya: Floristic and Ecological Aspects
Abstract
Naturalisation is the most crucial stage along the ecological process of introduction-naturalisation-invasion continuum. Therefore, reporting the transition of alien plant species at the naturalised stage along the continuum can be crucial for the early warning and rapid response in invasion management. Here we report Ranunculus repens as a new distribution record from Kashmir Himalaya. We provide a floristic account of this newly naturalised species and photographic illustrations of the distinguishing characters from an allied species, R. bulbosus, with which it is misidentified in the region. We also investigated the ecological aspects of this naturalised species by undertaking quadrat sampling in the R. repens-dominated community. Our results revealed that R. repens show positive association with those native species in the community which possess similar traits, but show interestingly negative association with other alien species found within the same community, thus hinting towards habitat filtering among the alien species pool in the region. Hopefully, the present study will validate report of R. repens from this Himalayan region, facilitate its field identification, guide control strategies at this early stage of naturalisation when chances of management success are maximum and prompt further studies on its potential invasion risk.
Supplemental data for this article is available online at https://doi.org/10.1080/11263504.2022.2036847.
... Because of its location near the junction of the Holarctic and Paleotropical Floristic Realms, the region is home to rich floristic diversity that is both economically and scientifically valuable (Dar and Khuroo, 2013). Recently, owing to the exceptionally high rate of land-use change, urbanisation, and warming climate, the region is experiencing a higher risk of alien plant invasions (Khuroo et al., 2010;Gulzar et al., 2022). Although previous studies have investigated the increasing occurrence of invasive alien flora in the Kashmir Himalaya: taxonomic documentation (Gulzar et al., 2021;Khuroo et al., 2007); ecological impacts (Ahmad et al., 2019;Shah and Reshi, 2014), this forms the first study to predict the drivers of invasive alien plant species in the region. ...
Invasive alien species (IAS) are currently considered as one of the major causes of global environmental change. To manage the IAS, it is crucial to identify the different environmental and associated anthropogenic drivers that contribute to invasion of alien species in non-native regions. Although multiple drivers of invasion have been identified at a global scale, the relative roles of these are known to vary considerably at regional scales. Here, we investigate the role of key environmental and anthropogenic drivers in determining the diversity and distribution of selected invasive alien plant species in Kashmir Himalaya. We generated an extensive distribution dataset of these species through field sampling across the region and supplemented it with novel herbarium records. We also extracted data on the relevant environmental (climatic, soil and topographic) and anthropogenic drivers for the study region. The random forest model was employed to quantify the relative contribution of these drivers to determine the two common diversity metrics (species richness and abundance) of selected invasive alien plants. We found that soil water content followed by distance to city, the maximum air temperature, soil pH, soil temperature and human population density exerted the greatest influence on species richness of the invasive plants. Species abundance was significantly influenced by the maximum air temperature followed by soil temperature, distance to city, slope, soil pH and human population density. Overall, our findings help in disentangling the individual and interactive roles of multiple drivers of plant invasions, with wide-ranging implications for management in this Himalayan region and similar landscapes elsewhere.
... The cultivated pool of alien flora is as equally important as the naturalized pool because it acts as the future source of potentially invasive species . Several case studies exist in which the species were initially under cultivation, but with time have escaped into the wild and grow at different stages along a naturalization-invasion continuum (Khuroo et al., 2012Gulzar et al., 2022). ...
The Himalaya – a global biodiversity hotspot – harbours diverse flora and fauna, but increasingly beset with multiple threats, including biological invasion by invasive alien species. Here, we aimed to investigate the diversity, distribution, and drivers of alien flora in the Indian Himalayan Region (IHR), a region spread across 12 states/union territories in India. We developed a comprehensive checklist on alien flora of IHR based on review of 141 studies published from 1934-2022, and further disentangled the key environmental (average annual rainfall, total area, protected area, forest area, total plant richness) and socioeconomic (total population, traffic length) correlates that better explain regional alien and naturalizd plant richness. We recorded 771 alien plant species, including 375 cultivated and 396 naturalized species. We found the species native to Southern America and those with perennial life span and herbaceous growth form were most represented in the IHR. Similarly, the annual herbs native to Southern American had a higher probability to become naturalized in the IHR. Based on the species composition of the total alien and naturalised flora distributed across different parts of the IHR, we found evidence of distance decay of floristic similarity. The total alien plant richness was best explained by the average annual rainfall, while the naturalized plant richness was best predicted by total traffic length. Our results identify the key environmental (i.e., average annual rainfall) and socioeconomic (i.e., total traffic length) drivers that determine the diversity and distribution patterns of alien and naturalized plants in the IHR. Our findings have practical applications in developing a scientifically-informed management and policy framework to mitigate the impacts of plant invasions and to predict the potential future plant invaders in the Himalaya. Overall, the checklist of alien flora of the IHR represents a step forward in filling the knowledge gaps on biological invasions from the Himalaya – a globally data-deficient region.
We are currently living in an age of Anthropocene [1]. Amongst the dominant drivers of Anthropocene, biological invasions by alien species are recognised as the second greatest threat to global biodiversity after habitat loss [2]. In recent times, the rising global trade, travel and transport have accelerated the rate of species’ introductions outside their native biogeographic ranges [3]. Worldover, a significant proportion of the introduced species pool has become naturalised and some of these spread as invasive in their non-native ranges, causing significantly high ecological and economic impacts affecting nature and nature’s contribution to all life forms [4, 5]. In response, concerted efforts are being made across the globe to focus scientific research, strengthen biosecurity, formulate policies and implement management strategies to combat biological invasions [6–8].
Invasive alien species are currently considered as one of the dominant drivers of global environmental change. Till now, the majority of studies have focused on single or a few traits of alien species that facilitate their invasion. Also inclusion of all the traits which determine the transition of aliens along the different stages of invasion continuum (casual, naturalised and invasive) has remained largely overlooked. In this study, we collected a comprehensive trait dataset on 144 alien plant species of Kashmir Himalaya – a global biodiversity hotspot region. To test which traits of alien species, individually or in combination along with anthropogenic factors, determine their transition along the invasion continuum, we employed chi-square tests, boosted regression trees and phylogenetic methods. We found the perennial lifespan, longer residence time, greater number of introduced regions, and better seed dispersal mechanism were critical in determining the transition from casual to naturalised. The herbaceous growthform (therophytes), annual lifespan, achene fruit, longer residence time and broader introduced range were the species’ traits determining transition from naturalised to invasive. Aliens introduced as ornamentals have more propensity to become naturalised; whereas aliens introduced unintentionally show overrepresentation at the invasive stage. Phylogeny alone showed mixed results indicating both clustering and dispersion; however in combination with other traits, it plays a significant role in determining the stage of invasion. Overall, our results disentangle the individual and interactive roles of multiple traits that determine the transition of alien species’ along the invasion continuum. Further, we foresee the potential applicability of our findings in designing robust invasion risk analysis protocols and stage-specific invasion management strategies in this Himalayan region, with learnings for elsewhere in the world.
Several species of the regional pool rarely become part of local communities. Such a con- siderable fraction of the species pool which remains absent but have potential to establish is referred to as dark diversity, and has till now remained understudied. In this study, we aimed to estimate the dark diversity, site-specific species pool, community completeness and species co-occurrence patterns in the Himalaya. Following a globally standardised sampling protocol, we delineated a circle of radius 10 km in the high-altitudes habitats of Kashmir Himalaya and selected two major habitat types: temperate coniferous forest and alpine grassland. Within each habitat type, we laid two 10-m2 core and two 50-m2 surrounding plots at natural and disturbed sites, and also thirty 10-m2 co-occurrence plots. The size of dark diversity was found higher at the disturbed sites (grassland: 23.43, for- est: 29.07) in comparison to the natural ones (grassland: 21.52, forest: 26.08). Conversely, the site-specific species pool size was higher in the natural sites (grassland: 44.53, forest: 51.08) as compared to the disturbed ones (grassland: 35.43, forest: 45.07), and a similar trend was observed for the community completeness index at both the habitats. The major- ity of the species co-occurrences in both the habitats were truly random, therby indicating possibly least role of biotic and abiotic factors. Our study provides empirical estimates of dark diversity and quantifies how they differ in natural and disturbed sites in Kashmir Hi- malaya. These findings have immediate implications in guiding site-specific biodiversity conservation and ecosystem restoration in the study region, and also hold promise to be upscaled at much larger spatial scales.
Plant-pollinator studies are increasingly using network analysis to investigate the structure and function of such communities. However, many areas of high diversity largely remained unexplored in this way. Our study describes a plant-pollinator meta-network from an overlooked biodiversity hotspot, the Kashmir Himalaya, where we specifically investigate plant-pollinator network nestedness and modularity, as well as the influence of alien species and the impacts of simulating species extinctions on network structure. Natural history observations were used to document the meta-network between 230 plant and 80 pollinator species forming 1958 (11% of the possible) interactions. Among the plants Malus domestica and among the pollinators Apis mellifera and A. cerana formed the largest number of interactions with significant influence over the whole network. Network cumulative degree distribution depicted a higher number of degree levels in pollinators than plants. A moderately high number of realized interactions were revealed, thereby indicating potential structural and functional stability in the network. Eight strongly defined modules were observed in the network which varied in their composition. For example, the Ephedra module exclusively comprised of native species whereas the Apis module comprised of all the four different types of interacting species (i.e. native and alien plants and pollinators) and also integrated the highest number of alien species. In the network overall, 40% of interactions were by alien species, reflecting how well these were integrated. Extinction simulations suggested that the network would collapse more quickly when the most connected pollinators are removed, rather than the most connected plant species. Our study is the first assessment of a plant-pollinator network from the Himalayan biodiversity hotspot; and will help to inform the ecological and economic implications of plant-pollinator interactions in an era of global biodiversity crisis.
Phyto-ecological studies are essential in understanding community structure, organization and their response to changes in other environmental factors. In this study we analyzed the phytosociological and soil characteristics of Phytolacca acinosa communities and their correlation. 110 quadrats were laid across ten randomly selected sites in Kashmir Himalaya, India. Soil analysis was done using standard protocols. Overall, 161 species were recorded, belonging to 128 genera and 49 families. The species richness (SR) ranges from 27 to 83. Highest IVI was recorded for Poa angustifolia (60.06) and least for Berberis lycium, Abies pindrow, Plectranthus ragosus, and Ailanthus altissima (0.37 each). P. acinosa showed 100% random associations with other plant species. Soil properties varied significantly across the selected sites. Significant positive correlation was found between species richness (SR), Organic matter (OM) (r = 0.79), Organic carbon (OC) (r = 0.79) and Shannon–Wiener index (H) (r = 0.92). Nitrogen content also showed positive correlation with SR and H. Floristic composition of P. acinosa assemblages was governed by soil properties and habitat characteristics of sampling sites. Areas with highest floral diversity had high soil fertility while areas with low soil fertility possess lower diversity and need restoration. The knowledge may prove helpful in management of these habitats, boost conservation and mitigate the effects of changing climate.
Globalisation has facilitated the spread of alien species, and some of them have significant impacts on biodiversity and human societies. It is commonly thought that biological invasions have accelerated continuously over the last centuries, following increasing global trade. However, the world experienced two distinct waves of globalisation (~1820–1914, 1960‐present), and it remains unclear whether these two waves have influenced invasion dynamics of many species. To test this, we built a statistical model that accounted for temporal variations in sampling effort. We found that insect and plant invasion rates did not continuously increase over the past centuries but greatly fluctuated following the two globalisation waves. Our findings challenge the idea of a continuous acceleration of alien species introductions and highlight the association between temporal variations in trade openness and biological invasion dynamics. More generally, this emphasises the urgency of better understanding the subtleties of socio‐economic drivers to improve predictions of future invasions. It is commonly thought that biological invasions have accelerated continuously over the last centuries, following increasing global trade. However, the world experienced two distinct waves of globalization (~1820–1914, 1960‐present), and it remains unclear whether these two waves have influenced invasion dynamics of many species. To test this, we built a statistical model that accounted for temporal variations in sampling effort, and found that insect and plant invasion rates did not continuously increase over the past centuries, but greatly fluctuated following the two globalization waves.
Across the continents, plant invasion is identified as one of the main threats to ecosystem functioning and stability. The main objective of this research was to evaluate the differences in the functional traits between invasive alien (Ageratina adenophora (Spreng.) and Lantana camara L.) and native (Berberis asiatica Roxb. Ex DC., Pyracantha crenulata (D. Don.) M. Roemer and Rubus ellipticus Sm.) shrub species of chir pine (Pinus roxburghii Sarg.) forest in the central Himalaya. Three 0.5 hectare chir pine forest stands were selected and individuals of similar diameter were tagged for comparative studies of leaf traits, growth pattern, and biomass accumulation in structural organs of each invasive alien and native species. Our one-way ANOVA and Tukey’s post hoc test results showed that both the invasive alien species have significantly (p < 0.05) higher SLA, LWC, total chlorophyll content, foliar nutrient (N and P), RGR, LMR, SMR, nutrient uptake, and nutrient use efficiencies than native species. Leaf litter decomposition rate and nutrient release were also significantly (p < 0.05) higher in both the invasive alien species. Native species, R. ellipticus, shared some of the traits, such as leaf area, chlorophyll content, RGR, LAR, LMR, and nutrient uptake efficiency with invasive alien species. The majority of traits differed among invasive alien and native species, implying that the success of invasive alien species is best described by being functionally distinct from native species. These findings indicate that invasive alien species had advanced functional traits which may be playing an important role in a rapid spread in the central Himalaya.
Symphyotrichum subulatum (Michx.) G.L.Nesom (Asteraceae) is reported as a new alien plant record for Kashmir Himalaya. The taxonomic identification of species is confirmed on the basis of shape of involucre, floral and seed characters. Detailed description, distribution map, and comments on distribution and ecology are also provided along with photographic illustration to facilitate easy identification of this species. Citation: Gulzar R, Khuroo AA, Rather ZA, Ahmad R, Rashid I (2021) Symphyotrichum subulatum (Michx.) G.L.Nesom (Asteraceae): a new distribution record of an alien plant species in Kashmir Himalaya, India. Check List 17 (2): 569-574. https://doi.
The sustainable management of green spaces in cities is crucial in achieving the challenging goal of urban sustainability. The common practice of cultivation of alien plants in urban green spaces is often associated with risk of naturalisation (i.e. escape into wild), which can have sometime adverse impacts on biodiversity and ecosystem services. To mitigate these risks, understanding patterns and processes of naturalisation of alien flora in urban green spaces becomes crucial. Here we report the floristic diversity of alien flora and correlates of its naturalisation in the green spaces of Srinagar city – one of the largest urban centres in the Himalaya. We documented 342 plant species belonging to 66 families from the green spaces of Srinagar, predominantly represented by 245 alien species (72%). Among the alien species pool, 133 species (54%) are exclusively under cultivation (non-escapes) and 112 species (46%) grow in the wild (cultivation escapes and accidentally introduced species); and of the latter, 51 were naturalised, 39 casual and 22 invasive. The cultivated alien species escaped into the wild belong to 27 families, and most prominently to the Asteraceae. Habitat-wise, plant dumping sites in the green spaces constituted the most dominant habitat of cultivation escapes. A significant relationship was revealed between the proportion of aliens under cultivation and species traits such as growth form, life span and residence time; and plant species with herbaceous growth form, annual life span and relatively longer residence time showed higher proportion of naturalisation. We found a significant correlation between abundance of the cultivation escapes and residence time (r = 0.507). The present study has generated policy-relevant data on urban green spaces of Srinagar, which can support policy regulations to steer the sustainable development of this rapidly urbanising Himalayan city.
Kashmir Valley has been witnessing erratic snowfall events in recent autumns which severely impacted apple orchards and harvests. Here, we combine remotely sensed data and field observations to map snowfall distribution and snow depths during the recent snowfall events in November 2018 and November 2019. Besides, we used ERA-5 reanalysis climate datasets to investigate the causes of these erratic snowfall events, pointing to an early arrival of Western Disturbances (WD) to the area. Analysis of these untimely snowfall episodes indicates that snow depths varied from 5-122 cm and 31-152 cm during the 2018 and 2019 snowfall events, respectively. In turn, satellite data analysis reveals that the apple orchards cover roughly 9.8% (1329 km 2) of the entire surface of Kashmir Valley, out of which 32.6% were mildly to severely damaged by snow. The areas in South Kashmir suffered the most from the untimely snowfall with an area affected estimated to~264 km 2 , followed by North Kashmir (~151 km 2) and Central Kashmir (18 km 2). The snowfall caused substantial harvest losses in orchards ranging from 4-50% with an average of~35%. The geopotential analysis from the ERA-5 dataset provides insights into the synoptic weather patterns leading to the snowfall events and point to a trough in the high-troposphere (200 mb), along with a col at lower levels (850 mb) over the Kashmir Valley from November 2-5, 2018. The lower levels (850 mb) experienced intense cyclonic circulation which favored advection of moisture from the Arabian Sea during the November 6-7, 2019, snowfall event. The large economic losses related to early arrival of WD led to a virtual grounding of the horticultural sector in 2018 and 2019. Therefore, more baseline research is critically needed along with a comprehensive evaluation of the suitability of horticulture as an economically viable sector that is being promoted over the Kashmir region, also under climate change.
Under the contemporary climate change, the Himalaya is reported to be warming at a much higher rate than the global average. However, little is known about the alpine vegetation responses to recent climate change in the rapidly warming Himalaya. Here we studied vegetation dynamics on alpine summits in Kashmir Himalaya in relation to in situ measured microclimate. The summits, representing an elevation gradient from treeline to nival zone (3530–3740 m), were first surveyed in 2014 and then re-surveyed in 2018. The initial survey showed that the species richness, vegetation cover and soil temperature decreased with increasing elevation. Species richness and soil temperature differed significantly among slopes, with east and south slopes showing higher values than north and west slopes. The re-survey showed that species richness increased on the lower three summits but decreased on the highest summit (nival zone) and also revealed a substantial increase in the cover of dominant shrubs, graminoids, and forbs. The nestedness-resultant dissimilarity, rather than species turnover, contributed more to the magnitude of β-diversity among the summits. High temporal species turnover was found on south and east aspects, while high nestedness was recorded along north and west aspects. Thermophilization was more pronounced on the lower two summits and along the northern aspects. Our study provides crucial scientific data on climate change impacts on the alpine vegetation of Kashmir Himalaya. This information will fill global knowledge gaps from the developing world.
Two contradictory hypotheses have been put forth to forecast alien invasiveness: being either functionally similar, or dissimilar, to resident natives along environmental gradients. The 'try-harder' hypothesis predicts that alien plants will be functionally dissimilar to natives and should thus exhibit exaggerated trait values when compared to natives in respect to resource extraction or stress tolerance. In contrast, the 'join-the-locals' hypothesis, which is compatible with ''environmental filtering'', predicts functional similarities among alien and native species in richer, but not in resource-limited environments. Here, we propose a framework that links the successful alien plant strategy, i.e. being functionally similar or dissimilar to natives, to the harshness of the environment and the availability of resources. We tested these two hypotheses using a trait-environment dataset of 33 alien and 130 native plants in 96 sites covering a gradient of soil resources (organic matter, nitrogen, soil moisture) in Saint-Katherine, an arid protected area in Egypt. We estimated 18 interaction coefficients between three candidate traits (specific leaf area, above-ground biomass, height) of alien and native plants as well as soil resources using linear mixed-effects models. Additionally, we calculated the mean and the hierarchical functional distance among aliens and natives along soil gradients. Our results revealed that in extreme resource-limited environments , aliens and natives were functionally similar and had relatively equal trait values consistent with environmental filtering, thus supporting the 'join-the-locals' hypothesis. However, in environments richer in resources, aliens and natives were functionally dissimilar with aliens exhibiting more exploitative trait values (taller, higher SLA and biomass) than natives, providing support for the 'try-harder' hypothesis. While demonstrated in only one arid system, results suggest that linking soil resource availability with functional divergence and convergence among native and alien plants could be used as an informative strategy to predict alien invasiveness. Hence, future studies should investigate the functional response of alien and native plants in different environments against different resource gradients to test for the generality of the patterns we found.
The Himalaya, a global biodiversity hotspot, sustains about one-fifth of the humankind. Nestled within the north-western mountain ranges of the Himalaya, the Jammu and Kashmir (J&K) State harbours more than half of the biodiversity found in the Indian Himalaya. The wide expanse of State, spread across the subtropical Jammu, through the temperate Kashmir valley, to the cold arid Ladakh, is typical representative of the extensive elevational and topographical diversity encountered in the entire Himalaya.
This book, the most comprehensive and updated synthesis ever made available on biodiversity of the J&K State, is a valuable addition to the biodiversity literature with global and regional relevance. The book, arranged into 7 parts, comprises of 42 chapters contributed by 87 researchers, each of whom is an expert in his/her own field of research. The precious baseline data contained in the book would form the foundation for assessing current status of knowledge about the bioresources, identify the knowledge gaps, and help prioritization of conservation strategies to steer the sustainable use of biodiversity in this Himalayan region. Given the breadth of topics covered under the banner of biodiversity in this book, it can surely serve as a model for documentation of biodiversity in other regions of the world. The book will be of immense value to all those who, directly or indirectly, have to deal with biodiversity, including students, teachers, researchers, naturalists, environmentalists, resource managers, planners, government agencies, NGOs and the general public at large.
Invasion by alien species is a global problem and forms one of the major drivers of global change. The researches on plant invasion have grown rapidly across the globe since the mid-twentieth century. However, in the Indian Himalayan Region (IHR) such studies are inadequate and have not been systematically conducted. Lack of empirical evidences on various described aspects of plant invasion in IHR are likely to aggravate the issue of invasion management in the region. This scenario would become more worst under changing climate. This study analyzed the results of an extensive review of the available information generated through Web of Science and Google scholar. A total of 297 naturalized alien plant species belongs to 65 families in the IHR are reported. Of the total 297 naturalized alien plant species in IHR, maximum species occur in Himachal Pradesh (232; 78.1%) followed by Jammu & Kashmir (192; 64.6%) and Uttarakhand (181; 60.90%). Among various invasive species, Lantana camara, Ageratina adenophora, Parthenium hysterophorus and Ageratum conyzoides have been reported from most of the IHR states and proliferated over larger area. Evidences available in the published studies are indicative that with tourism promotion and increasing roads networks, that passes through forests, many of the alien species in the IHR have started invading forests and even in alpine ecosystems. This study observed expansion of Ageratina adenophora up to 2900 m, which is higher than its reported elevation range (300–2800 m) in west Himalaya. These evidences suggest possible encroachment by alien species in hitherto invasion resilient higher Himalaya, particularly with emerging trends of increasing temperature and human disturbances. The present study also provides a multistage framework for investment on invasion researches in IHR. This will allow developing appropriate management strategies and policy planning for addressing issues pertaining to plant invasions across the IHR states.
Aim
Horticulture has been recognized as the main pathway of plant invasions worldwide. The selection of ornamental garden plants is not random, and certain plant characteristics related to adaptive plant strategies are preferred by horticulture and may promote invasion. We examined the direct and indirect interactions between horticultural use, species adaptive strategies (competitive (C), stress‐tolerant (S), and ruderal (R)), native range size and naturalization success.
Location
Global.
Time period
From 1492 to the present.
Major taxa studied
Vascular plants.
Methods
We compiled a dataset of 3,794 plant species including their C‐, S‐ and R‐scores, native range size, cultivation in botanic and domestic gardens and whether the species is naturalized in at least one region globally (naturalization incidence). For the 1,711 naturalized species, we also calculated naturalization extent, that is, the number of regions where the species has naturalized. We used phylogenetic path analysis to disentangle the direct and indirect effects of all variables on both naturalization incidence and extent, and the relationships between variables.
Results
Approximately 87 and 94% of the 1,711 naturalized species were cultivated in botanic or domestic gardens, respectively, compared to c. 55 and 50% of the 2,083 non‐naturalized species, respectively. We found a cascading structure among the examined variables: (a) species exhibiting C‐ or R‐selected strategies and having large native ranges tended to be cultivated in domestic and botanic gardens, became naturalized outside their native ranges and occupied more regions in their naturalized ranges; (b) C‐, S‐ and R‐scores also had indirect effects on naturalization success, which were mediated by horticultural use and native range size; and (c) cultivation in domestic gardens was the strongest factor examined that could explain plant species’ naturalization success.
Main conclusions
We show that horticulture is not only the major introduction pathway of alien plants, but also that in particular domestic gardens select species predisposed to invade and naturalize.
Mountains make up 24% of the world’s land area, are home to 20% of the world’s population, provide 60–80% of the world’s fresh water, and harbour 50% of the world’s biodiversity hotspots (well-established). The United Nations recognized the importance of mountain ecosystems, both for conserving biological diversity and for sustaining humanity, in Chap. 13 of Agenda 21. More generally, ecosystem diversity, species diversity, genetic diversity, and functional diversity all play key roles in the ecosystem services that benefit people and communities (well-established).
Western Himalaya is an important region in terms of its enriched biodiversity and immense ecosystem services (ESS). However, its biodiversity and ESS are under tremendous pressure from rapid population growth, developmental activities, unplanned urbanization, agricultural expansion, climate change, and the associated changes in land use and land cover (LULC). This study provides a systematic review of the composition and pattern of LULC (from existing literature) and the effects of LULC change on various ESS provided by the western Himalayan ecosystems. Despite being such a significant area, data and studies concerning the impacts of LULC change on the spatial distribution of ESS, focused particularly on the western Himalayan region are inadequately reported. Most existing studies indicate a general decrease in forest cover and an increase in forest fragmentation along with generally increasing trends in built-up areas, croplands, and barren lands. These results imply ecosystem degradation and a reduction in the potential for the sustainable flow of ESS from this region. In this respect, this study suggests that quantification and spatial mapping of ESS in the western Himalayan region is conducted.
Invasive alien plant species (IAPS) can pose severe threats to biodiversity and stability of native ecosystems, therefore, predicting the distribution of the IAPS plays a crucial role in effective planning and management of ecosystems. In the present study, we use Maximum Entropy (MaxEnt) modelling approach to predict the potential of distribution of eleven IAPS under future climatic conditions under RCP 2.6 and RCP 8.5 in part of Kailash sacred landscape region in Western Himalaya. Based on the model predictions, distribution of most of these invasive plants is expected to expand under future climatic scenarios, which might pose a serious threat to the native ecosystems through competition for resources in the study area. Native scrublands and subtropical needle-leaved forests will be the most affected ecosystems by the expansion of these IAPS. The present study is first of its kind in the Kailash Sacred Landscape in the field of invasive plants and the predictions of potential distribution under future climatic conditions from our study could help decision makers in planning and managing these forest ecosystems effectively.
The wide knowledge gaps in invasion biology research that exist in the developing world are crucial impediments to the scientific management and global policymaking on biological invasions. In an effort to fill such knowledge gaps, we present here an inventory of the alien flora of India, based on systematic reviews and rigorous analyses of research studies (ca. 190) published over the last 120 years (1890-2010 AD), and updated with field records of the last two decades. Currently, the inventory comprises of 1,599 species, belonging to 842 genera in 161 families, and constitutes 8.5% of the total Indian vascular flora. The three most species-rich families are Asteraceae (134 spp.), Papilionaceae (114 spp.) and Poaceae (106 spp.), and the three largest genera are Eucalyptus (25 spp.), Ipomoea (22 spp.), and Senna (21 spp.). The majority of these species (812) have no report of escaping from cultivation. Of the remaining subset of 787 species, which have either escaped from intentional cultivation, or spread after unintentional introduction, casuals are represented by 57 spp., casual/naturalised by 114 spp., naturalised by 257 spp., naturalised/invasive by 134 spp., and invasive by 225 spp. Biogeographically, more than one-third (35%) of the alien flora in India has its native ranges in South America, followed by Asia (21%), Africa (20%), Europe (11%), Australia (8%), North America (4%); and cryptogenic (1%). The inventory is expected to serve as the scientific baseline on plant invasions in India, with implications for conservation of global biodiversity.
Significance
This work provides a complete experimental answer to the longstanding question of which local factors determine the success (i.e., establishment, growth, and flowering) of common nonnative plant invaders at their coldest physiological limits. Using a multifactorial seed-addition experiment along repeated elevational gradients in two sub(ant)arctic mountain regions, we pinpoint the relative contribution of all main candidate determinants: temperature, disturbance, nutrient addition, and propagule pressure. We warn that climate change and direct human disturbances will together result in increased plant invasion in cold-climate ecosystems in the near future.
Recent years have seen a surge of interest in understanding patterns and processes of plant invasions into mountains. Here, we synthesise current knowledge about the spread of non-native plants along elevation gradients, emphasising the current status and impacts that these species have in alpine ecosystems. Globally, invasions along elevation gradients are influenced by propagule availability, environmental constraints on population growth, evolutionary change and biotic interactions. The highest elevations are so far relatively free from non-native plants. Nonetheless, in total nearly 200 non-native plant species have been recorded from alpine environments around the world. However, we identified only three species as specifically cold-adapted, with the overwhelming majority having their centres of distribution under warmer environments, and few have substantial impacts on native communities. A combination of low propagule availability and low invasibility likely explain why alpine environments host few non-native plants relative to lowland ecosystems. However, experiences in some areas demonstrate that alpine ecosystems are not inherently resistant to invasions. Furthermore, they will face increasing pressure from the introduction of pre-adapted species, climate change, and the range expansion of native species, which are already causing concern in some areas. Nonetheless, because they are still relatively free from non-native plants, preventative action could be an effective way to limit future impacts of invasions in alpine environments.
The International Centre for Integrated Mountain Development is coordinating the Hindu Kush Himalayan Monitoring and Assessment Programme, which will be carried out with partners and individual experts. The assessment addresses the social, economic, and environmental pillars of sustainable mountain development and will serve as a basis for evidence-based decisionmaking to safeguard the environment and advance people’s wellbeing. It is not a one-off assessment but will be an ongoing process. A 2017 publication is
planned as the first of a series of monitoring and assessment reports.
The observation that species may be positively or negatively associated with each other is at least as old as the debate surrounding the nature of community structure which began in the early 1900's with Gleason and Clements. Since then investigating species co-occurrence patterns has taken a central role in understanding the causes and consequences of evolution, history, coexistence mechanisms, competition, and environment for community structure and assembly. This is because co-occurrence among species is a measurable metric in community datasets that, in the context of phylogeny, geography, traits, and environment, can sometimes indicate the degree of competition, displacement, and phylogenetic repulsion as weighed against biotic and environmental effects promoting correlated species distributions. Historically, a multitude of different co-occurrence metrics have been developed and most have depended on data randomization procedures to produce null distributions for significance testing. Here we improve upon and present an R implementation of a recently published model that is metric-free, distribution-free, and randomization-free. The R package, cooccur, is highly accessible, easily integrates into common analyses, and handles large datasets with high performance. In the article we develop the package's functionality and demonstrate aspects of co-occurrence analysis using three sample datasets.
The Kashmir Himalaya, being nestled within north-western folds of the Himalaya, harbours a rich floristic diversity of immense scientific interest and enormous economic potential. Though scientific studies on the floristic diversity in the Kashmir Himalaya have been started about two centuries ago, yet they fall short of the requirements needed urgently in the post-Rio Summit. In fact, at the spatial scale, many far flung areas and difficult terrains in the hinterland are still either least- or totally-unexplored; and at the taxon scale, floristic studies especially with regard to the lower plants are insufficient, thus posing serious problems in assessing the floristic diversity in the region. With such a perspective in hindsight, the present paper dilates upon the progress achieved so far, highlights the problems being faced and envisages the future prospects with regard to floristic diversity in this region. First, a broad overview of the current status of floristic diversity in this Himalayan region is presented, followed by a critical analysis of the knowledge base presently available on various taxonomic groups of plants. The yawing gaps in our knowledge of floristic diversity in this region are identified and an action plan to bridge these gaps is also outlined. Hopefully, addressing these challenges in the immediate future could facilitate the documentation, conservation and sustainable use of plant resources in this region, so as to steer this 'Himalayan Paradise' towards the path of sustainable development.
Alien flora of the Czech Republic is presented. In Appendix 1, 1378 alien taxa (33.4% of the total flora) are listed with information on the taxonomic position, origin, invasive status (casual, naturalized, invasive; a new category post-invasive is introduced), time of immigration (archaeophytes vs. neophytes), habitat type invaded (natural, seminatural, human-made), vegetation invaded (expressed as occurence in phytosociological alliances), mode of introduction into the country (accidental, deliberate), and date of the first record. Number of phytogeographical as well as biological and ecological attributes were compiled for each species in the database; its structure is presented in Appendix 2 as a suggestion for similar work elsewhere. Czech alien flora consists of 24.1% of taxa which arrived before 1500 (archaeophytes) and 75.9% neophytes. There are 891 casuals, 397 naturalized and 90 invasive species. Of introduced neophytes, 21.9% became naturalized, and 6.6% invasive. Hybrids contribute with 13.3% to the total number of aliens, and the hybridization is more frequent in archaeophytes (18.7%) than in neophytes (11.7%). If the 184 hybrids are excluded from the total number of aliens, there are 270 archaeophytes and 924 neophytes in the Czech flora, i.e. total of 1195 taxa. Accidental arrivals account for 53.4% of all taxa and deliberate introduction for 46.6%; the ratio is reversed for neophytes considered separately (45.5 vs. 54.5%). Majority of aliens (62.8%) are confined to human-made habitats, 11.0% were recorded exclusively in natural or seminatural habitats, and 26.2% occur in both types of habitat. Archaeophytes and neophytes occur in 66 and 83 alliances, respectively, of the phytosociological system. Flora is further analysed with respect to origin, life histories, life forms and strategies. Only 310 species (22.4% of the total number of all alien taxa) are common or locally abundant; others are rare, based on a single locality or no longer present. The following 19 taxa are reported as new for the Czech alien flora: Agrostis scabra, Alhagi pseudalhagi, Allium atropurpureum, Bromus hordeaceus subsp. pseudothominii, Carduus tenuiflorus, Centaurea xgerstlaueri, Centaurea nigra x phrygia, Cerastium xmaureri, Gilia capitata, Helianthus strumosus, Hieracium pannosum, Hordeum leporinum, Oenothera coronifera, Papaver atlanticum subsp. mesatlanticum, Parietaria pennsylvanica, Polypogon fugax, Rodgersia aesculifolia, Sedum pallidum var. bithynicum, Sedum stoloniferum; these represent results of our own field research as well as of herbaria search, and unpublished data from colleagues. Other 44 taxa are reported as escaping from cultivation for the first time. Twenty two archaeophytes are listed in the Red List of the Czech flora.
The genus Ranunculus L. in India is taxonomically revised, based on morphological and phytogeographacial patterns. Forty-five taxa (41 species and 4 varieties) of Ranunculus have been recognized, of these, the taxonomic complexicity among the Ranunuculs cantoniensis DC., R. diffusus DC., R. hyperboreus Rottb. and R. pulchellus C.A.Mey. have been resolved in this treatment, and also several taxa were treated as synonymous to these species by the earlier workers, have been segregated either as infra-specific taxa or were merged under the species proper. Efforts have been made to check and study each and every taxon of Ranunculus known from India, represented in all the Indian and European herbaria and from the literature. Sixteen species of Ranunculus show a very meager representation in the herbaria and in the field as well. The present work also includes the lectotypification of eight species (article submitted for publication). A key to the species, nomenclatural citation of each species, their synonyms, details of type, taxonomic description, phenology, distribution in India and worldwide, exsiccata, ecological and taxonomical notes if any, have been provided. Line drawings of the habit and details of each species have been drawn wherever possible, based on the availability of the materials.The distribution of all the species in India has been shown on the maps.
Species moved by human activities beyond the limits of their native geographic ranges into areas in which they do not naturally occur (termed aliens) can cause a broad range of significant changes to recipient ecosystems; however, their impacts vary greatly across species and the ecosystems into which they are intro-duced. There is therefore a critical need for a standardised method to evaluate, compare, and eventually predict the magnitudes of these different impacts. Here, we propose a straightforward system for classifying alien species according to the magnitude of their environmental impacts, based on the mechanisms of impact used to code species in the International Union for Conservation of Nature (IUCN) Global Invasive Species Database, which are presented here for the first time. The classification system uses five semi-quantitative scenarios describing im-pacts under each mechanism to assign species to different levels of impact— ranging from Minimal to Massive—with assignment corresponding to the highest level of deleterious impact associated with any of the mechanisms. The scheme also includes categories for species that are Not Evaluated, have No Alien Population, or are Data Deficient, and a method for assigning uncertainty to all the classifications. We show how this classification system is applicable at different levels of ecological complexity and different spatial and temporal scales, and embraces existing impact metrics. In fact, the scheme is analogous to the already widely adopted and accepted Red List approach to categorising extinc-tion risk, and so could conceivably be readily integrated with existing practices and policies in many regions.
Knowledge on the main spatiotemporal trends in plant invasions of habitats is essential for a better understanding of the process of these invasions. The aim of this study was to determine the level of plant invasion, represented by relative richness and total cover of archaeophytes and neophytes, in 45 EUNIS habitat types along with spatiotemporal changes in invasion level with increasing altitude and time in Slovakia. In general, the most invaded habitats are those which are highly influenced by human activities. Generalized linear models and generalized linear mixed models were used to assess the associations between habitat-specific invasion level, altitude and time, respectively. There is a general decrease in the relative richness and total cover of archaeophytes and neophytes with increasing altitude in the invaded habitats. There is also an observable temporal trend in archaeophytes shifting from anthropogenic towards more natural habitats. Importantly, the relative neophyte richness has recently been increasing, predominantly in semi-natural and natural habitats, which brings about major concerns for nature conservation. This may be the manifestation of a lag phase in the dispersal of neophytes. However, accompanied with a significant increase in the relative richness of archaeophytes in some natural habitats, it may indicate more complex changes in the invaded habitats and be an early warning sign for ecological degradation of these habitats.
The wide knowledge gaps in invasion biology research that exist in the developing world are crucial impediments to the scientific
management and global policymaking on biological invasions. In an effort to fill such knowledge gaps, we present here an inventory
of the alien flora of India, based on systematic reviews and rigorous analyses of research studies (ca. 190) published over
the last 120 years (1890–2010 AD), and updated with field records of the last two decades. Currently, the inventory comprises
of 1,599 species, belonging to 842 genera in 161 families, and constitutes 8.5% of the total Indian vascular flora. The three
most species-rich families are Asteraceae (134 spp.), Papilionaceae (114 spp.) and Poaceae (106 spp.), and the three largest
genera are Eucalyptus (25 spp.), Ipomoea (22 spp.), and Senna (21 spp.). The majority of these species (812) have no report of escaping from cultivation. Of the remaining subset of 787
species, which have either escaped from intentional cultivation, or spread after unintentional introduction, casuals are represented
by 57 spp., casual/naturalised by 114 spp., naturalised by 257 spp., naturalised/invasive by 134 spp., and invasive by 225
spp. Biogeographically, more than one-third (35%) of the alien flora in India has its native ranges in South America, followed
by Asia (21%), Africa (20%), Europe (11%), Australia (8%), North America (4%); and cryptogenic (1%). The inventory is expected
to serve as the scientific baseline on plant invasions in India, with implications for conservation of global biodiversity.
Much attention has been paid to negative effects of alien species on resident communities but studies that quantify community‐level effects of a number of invasive plants are scarce. We address this issue by assessing the impact of 13 species invasive in the Czech Republic on a wide range of plant communities.
Vegetation in invaded and uninvaded plots with similar site conditions was sampled. All species of vascular plants were recorded, their covers were estimated and used as importance values for calculating the Shannon diversity index H′ , evenness J and Sørensen index of similarity between invaded and uninvaded vegetation.
With the exception of two invasive species, species richness, diversity and evenness were reduced in invaded plots. Species exhibiting the greatest impact reduced species numbers per plot and the total number of species recorded in the communities sampled by almost 90%. A strong reduction of species number at the plot scale resulted in a marked reduction in the total species number at the landscape scale, and in less similarity between invaded and uninvaded vegetation. The decrease in species richness in invaded compared to uninvaded plots is largely driven by the identity of the invading species, whereas the major determinants of the decrease in Shannon diversity and evenness are the cover and height of invading species, and differences between height and cover of invading and dominant native species, independent of species identity.
Synthesis. Management decisions based on impact need to distinguish between invasive species, as their effects on diversity and composition of resident vegetation differ largely. Tall invading species capable of forming populations with the cover markedly greater than that of native dominant species exert the most severe effects on species diversity and evenness. Since a strong impact on the community scale is associated with reduction in species diversity at higher scales, invaders with a high impact represent a serious hazard to the landscape.
A continuing lack of consensus on the operational characterisation of alien invasive species (AIS) in invasion biology has
hampered the integration of research results generated worldwide. This impedes our progress in devising sound management strategies
to stem the tide of biological invasions. In this regard, we here use the neutral terminology model of Colautti and MacIsaac
(Divers Distrib 10:135–141, 2004) (CM model) for the characterization of alien invasive flora of the Kashmir Himalaya, India;
and more emphatically, expound the utility of such a stage-based operational framework in the management of plant invasions.
Out of the total of 436 alien invasive plant species recorded in the region, the number of species belonging to invasion stages
II, III, IVa, IVb and V was 119, 107, 56, 77 and 77 species, respectively. In terms of relative proportion of species belonging
to the different invasion stages, trees dominated the Stage-V (31.25%), followed by aquatics, subshrubs, biennial herbs, perennial
herbs, annual herbs and shrubs, in descending order. Based on the results obtained in the present investigation, and in an
attempt to link the characterisation of AIS with the management of plant invasions, we here propose a hierarchical management
framework based on prediction, prevention, prescription, and public awareness. While the present study focuses on plants only,
the proposed management framework can be operationally used across different taxonomic groups, and within varied ecosystems,
with potentially immense management implications.
Compilation of alien flora from phytogeographically distinct regions is of immediate relevance not only for better understanding
the patterns of plant invasion but also for explicating the processes promoting invasion at local, regional or global scales.
Despite being at higher risk of invasion by plants because of its European colonial past, south Asia has received very little
attention in respect of characterization of its alien flora. This paucity of baseline data necessitated compilation of the
first catalogue of alien flora from the Kashmir Himalaya—a phytogeographically distinct south Asian region nestled in the
northwestern folds of Himalayan biodiversity hotspot. Total alien flora of the region is represented by 571 plant species,
belonging to 352 genera and 104 families. It constitutes a relatively higher (29%) proportion of the total flora of the region.
Families with largest number of alien representatives are Poaceae (60 species), Asteraceae (54 species), and Brassicaceae
(30 species). However, families such as Amaranthaceae (83%) and Chenopodiacae (71%) show higher percentage of aliens relative
to their total number of plant species in the region. Most of the alien plant species (38%) trace their origin to Europe,
followed by Asia (27%) and Africa (15%). Present study also reports, for the first time, occurrence of seven plant species
in this region. Each alien plant species is provided with information on the origin, habit, mode/purpose of introduction,
current invasion status, altitudinal range and the primary published source.
The turlough form of Ranunculus repens is subjected to several months' complete inundation with hard groundwater. Experimental flooding to the level of the soil surface had no effect on turlough or ruderal populations relative to drained controls. Experimental submergence resulted in direct tissue death of the ruderal population but did not affect the turlough population relative to drained controls. There was no detectable difference in the proportion of aerenchyma in drained, flooded and submerged roots of plants from either population. The proportion of aerenchyma increased with root age in the ruderal population. Up to twice the proportion of aerenchyma occurred in the lower third of the root in the turlough population relative to the middle and upper thirds. Submergence in artificially hardened tap water increased the amount of tissue death in the ruderal population, whereas it appeared to enhance the growth of plants from the turlough population relative to that of plants submerged in tap water. Only the ruderal population demonstrated a depth accommodation response in submerged conditions. Root concentrations of ethanol-soluble carbohydrates were up to three times higher in a field- collected turlough population during winter and autumn months than those in a ruderal population. Low levels of ethanol-insoluble carbohydrates were present in the turlough population but were absent from the ruderal population. Starch concentrations fluctuated greatly in the turlough population and were generally higher than those in the ruderal population. These results, together with those from previous investigations, suggest that the turlough population survives prolonged submergence by maintaining low levels of submerged photosynthesis, which may circulate oxygen within the plant tissues, and by utilizing storage carbohydrates for maintenance respiration.
In an era of Anthropocene, invasive alien species (IAS) are recognized as agents of global environmental change. Given the grave impacts of IAS on ecology, economy, health, and national security, scientific inventories of IAS have assumed urgent research priority. In this chapter, an annotated inventory of the invasive alien flora of India is presented. Taxonomically, a total of 145 invasive plant species belonging to 101 genera in 40 families have been documented with information about their distribution in 31 administrative states/union territories of India. The families richest in terms of invasive species are Asteraceae (27 species), Fabaceae (20 species), and Solanaceae (12 species). The highest and lowest numbers of invasive species are reported from Karnataka (117) and Sikkim (12), respectively. Biogeographically, majority of the invasive plant species in India as well as individual administrative states/union territories have Southern America as native range; annual and herb as the dominant lifespan and growth form categories, respectively. Hopefully, the chapter will serve as baseline data in developing the scientifically informed policy framework for management of plant invasions in India.
Questions
Due to the diverse abiotic conditions and the extensive, early‐autumn, manual mowing practiced once per few years, Molinia semi‐natural wet meadows are known due to their high plant species diversity. However, recent socio‐economic transformations and land use change (i.e. cessation of use) have been contributing to significant biodiversity loss in Molinia meadows. Thus, understanding the mechanisms of species co‐occurrence patterns operating on well‐developed Molinia meadows may be a precondition for the restoration or regeneration success of this type of vegetation. We aimed to identify community‐level coexistence patterns of the whole set of plant species typical of Molinia meadows, and to assess the role of co‐occurring vegetation in shaping the performance of individual species.
Location
Natura 2000 Special Area of Conservation “Łąki Dąbrowskie” (S Poland).
Methods
Using generalised multiple regression techniques, a set of vegetation traits and components of functional diversity, we assessed the role of different ecological mechanisms in shaping co‐occurrence patterns of the entire group of species typical of Molinia meadows, as well as individual species belonging to this group.
Results
When the entire group of Molinia meadow species was taken into account, niche differentiation emerged as the main mechanism influencing the co‐occurrence of plant species. When considering individual species, we revealed that their coexistence patterns were mostly species‐specific, pointing out the predominant role of either niche differentiation, competition, habitat filtering, or a combination of these three drivers in shaping assembly processes.
Conclusions
Our results showed that the variability of niches realised by target species typical of Molinia meadows was high. Therefore, conservation of well‐developed Molinia meadows should focus on both the community, and on a single species level, aiming to maintain a complex of specific microhabitat conditions. Considering small‐size patches of these meadows scattered in transformed, agricultural landscape, conservation of individual target species should be of the highest priority.
Question
Species of the genus Carpobrotus, or iceplant, are succulent mat‐forming perennial herbs often introduced for soil stabilization. They are common in coastal environments and may thus threaten island biodiversity. While their effects are well known on soils, plant communities and associated fauna, the effects of Carpobrotus control on vegetation recovery is poorly documented. The aim of the paper is to describe plant community trajectories after Carpobrotus removal.
Location
Bagaud: a 58‐ha Mediterranean island, southern France.
Methods
Carpobrotus and its litter were removed in 2011‐2012. Follow‐up controls of germinations and resprouts were carried out from then on. Plant communities were surveyed every year two years before and seven years after Carpobrotus removal: on two ca. 0.5‐ha sites (one coastal and one inland) and in three native plant communities used as potential references. Differences in resprouts, vegetation parameters, Bray–Curtis similarity indices between years were tested. Plant community dynamics was studied through a NMDS and two recovery indices.
Results
The removal of Carpobrotus and its litter led to the recovery of diverse native plant communities. To prevent Carpobrotus return and ensure success, follow‐up controls were necessary for a period of at least seven years, but the amount of work decreased with time. The plant community recovering on the coastal site quickly reached a composition and structure similar to that of non‐invaded coastal vegetation, although some slow‐growing native species remain under‐represented (e.g. Crithmum maritimum and Limonium pseudominutum). The plant community recovering on the inland site was still very different from the surrounding matorral vegetation because of its slow colonization dynamics, particularly in the presence of competitive herbaceous species.
Conclusion
Both sites now provide diverse native plant communities with a more diversified composition and structure (plant heights, litter, bare ground patches) than the plant communities which used to be associated with Carpobrotus mats.
In the present study, 4 gridded satellite precipitation data products for September 2014 flood, IMERG (Integrated Multi-satellitE Retrievals for GPM), GSMaP (Global Satellite Mapping of Precipitation), TRMM-3B42 (Tropical Rainfall Measuring Mission) and INSAT-3D-IMR (INSAT Multispectral Rain), were evaluated against the Indian Meteorological
Department rain-gauge data from Sep-1st to Sep-7th 2014. Three evaluation indices; Correlation coefficient (CC), the Relative bias (RB) and the NashSutcliffe coefficient (NSC), were used to evaluate the robustness of satellite precipitation estimates with actual rainfall measurements. IMERG precipitation product has a near perfect positive CC and NSC values of 0.94 and 0.99 respectively; while the CC and NSC values are 0.7 and 0.5 for GSMaP_Gauge; 0.69 and 0.05 for INSAT-3D-IMR; and 0.9 and 0.8 for TRMM-3B42 respectively. The RB estimates indicate that IMERG, with a bias of 2%, is a best-fit dataset when compared to the surface rain-gauge observations. In contrast, TRMM-3B42, GSMaP and INSAT-3D-IMR have underestimation biases of −31%, −58%, and − 86% respectively. Analysis of the indices indicates that IMERG precipitation product performed better than
other three satellite precipitation products owing to the closeness of values with surface gauge station data over Kashmir. Owing to scanty observation of rainfall in the region, IMERG has a potential to become a cost effective input data source for designing a flood early warning system (FEWS) for Kashmir. However, it is suggested to evaluate the robustness of different satellite derived precipitation estimates compared to rain gauge observations by incorporating more extreme events from different mountain regions globally for establishing the best satellite derived precipitation product.
Alien plant invasion and nutrient enrichment as a result of anthropogenic landscape modification seriously threaten native plant community diversity. It is poorly understood, however, whether these two disturbances interact with the functional identity of recipient native plants to drive community change. We performed a mesocosm experiment to examine whether the interactive effects of invasion by a stoloniferous turf-grass Stenotaphrum secundatum and nutrient enrichment vary across different plant growth forms of an endangered coastal plant community. Communities contained 18 species (drawn without replacement from a pool of 31 species) with either runner, tufted or woody growth forms. Species were well-established and reproductively mature prior to S. secundatum introduction. Species growth (% cover), reproductive output, soil temperature and light availability were monitored for two growing seasons. Invasion and nutrient enrichment (two levels: ‘natural control’ and ‘enriched’) had no effect on species richness, community composition, reproductive output, soil temperature or light penetration. There was no interactive effect of nutrients and invasion on community productivity (i.e. final biomass), such that invasion caused a reduction in community biomass at both natural and enriched nutrient levels. This was driven only by reduced biomass of functionally-similar native runner species, which share similar root morphologies and nutrient-acquisition strategies with S. secundatum. Our study indicates that impacts of invasion are dependent upon the functional identity of species within recipient communities, not the availability of resources. This shows that management cannot buffer invader effects by manipulating resource availability. Revegetation strategies should target functionally-similar natives for replacement following invader control.
In the last decade, habitat-oriented studies of plant invasions, performed at broad scales and using large data sets of vegetation plots, have focused on quantifying the representation of alien species in vegetation or habitat types, identifying factors underlying invasions, and exploring the pools of species available for invasion into particular habitats. In this essay we summarize what we have learned, discuss constraints associated with this kind of data and outline promising research topics to which a macroecological perspective of habitat invasions can contribute. Such topics include, among others: integrating species-specific information on invasion status, residence time in the region, biological and ecological traits and phylogenetic relationships into habitat invasion research to better capture the context-dependence of invasions; focusing on the functional role that alien species, relative to natives, play in plant communities; and obtaining insights into the role of pre-adaptation for invasion by comparing the functional composition of habitat species pools in the native range. There is still a strong geographic bias, with detailed assessments across broader ranges of habitat types in large regions available only from Europe, the United States and New Zealand, which call for extension of this research to other continents.
The paper provides the first estimate of the role of abiotic and anthropogenic variables driving both alien plant species richness and composition covering the whole region of the European Alps. To establish and spread in a new area, alien plants must be able to tolerate the prevailing climatic conditions. We therefore tested the hypothesis that climatic require-ments modified by bioclimatic origin and elevational distribution influence the distribution of alien plants in the Alps. Despite most alien plant species showing a relatively restricted distribution in the Alps, some regions, however, were already more strongly invaded. Most of these species were adapted to warmer conditions, probably constrained by climatic factors. Environmental heterogeneity was the most important predictor of alien plant species richness, followed by anthropogenic disturbance. Due to the political/artificial delineation of the administrative districts in the Alps (i.e., ignoring ecological condi-tions) we did not find a direct influence of climatic constraints on alien distribution. Anyway, northern Holarctic alien species showed a broader climatic tolerance and the capability to grow across a wide environmental range. Our results also reveal a strong influence of human pressure on warmer tropical
species, despite their low adaptability to anthropogenic habitats. To this aim, managers would profit from early warnings to prevent future invasions. Considering bioclimatic origin, our study can aid in identifying potentially invasive species in a more regional setting.
The literature on biological invasions is biased in favour of invasive species – those that spread and often reach high abundance following introduction by humans. It is, however, also important to understand previous stages in the introduction–naturalization–invasion continuum (‘the continuum’), especially the factors that mediate naturalization. The emphasis on invasiveness is partly because most invasions are only recognized once species occupy large adventive ranges or start to spread. Also, many studies lump all alien species, and fail to separate introduced, naturalized and invasive populations and species. These biases impede our ability to elucidate the full suite of drivers of invasion and to predict invasion dynamics, because different factors mediate progression along different sections of the continuum. A better understanding of the determinants of naturalization is important because all naturalized species are potential invaders. Processes leading to naturalization act differently in different regions and global biogeographical patterns of plant invasions result from the interaction of population‐biological, macroecological and human‐induced factors. We explore what is known about how determinants of naturalization in plants interact at various scales, and how their importance varies along the continuum. Research that is explicitly linked to particular stages of the continuum can generate new information that is appropriate for improving the management of biological invasions if, for example, potentially invasive species are identified before they exert an impact.
Contents
Summary
383
I.
Introduction
383
II.
The introduction–naturalization–invasion continuum for conceptualizing biological invasions
384
III.
The biogeographical background for studying naturalization: variation among populations and regions
385
IV.
Factors determining naturalization in plants
388
Acknowledgements
392
References
392
Much confusion exists in the English-language literature on plant invasions concerning the terms ‘naturalized’ and ‘invasive’ and their associated concepts. Several authors have used these terms in proposing schemes for conceptualizing the sequence of events from introduction to invasion, but often imprecisely, erroneously or in contradictory ways. This greatly complicates the formulation of robust generalizations in invasion ecology.
Based on an extensive and critical survey of the literature we defined a minimum set of key terms related to a graphic scheme which conceptualizes the naturalization/invasion process. Introduction means that the plant (or its propagule) has been transported by humans across a major geographical barrier. Naturalization starts when abiotic and biotic barriers to survival are surmounted and when various barriers to regular reproduction are overcome. Invasion further requires that introduced plants produce reproductive offspring in areas distant from sites of introduction (approximate scales: > 100 m over < 50 years for taxa spreading by seeds and other propagules; > 6 m/3 years for taxa spreading by roots, rhizomes, stolons or creeping stems). Taxa that can cope with the abiotic environment and biota in the general area may invade disturbed, seminatural communities. Invasion of successionally mature, undisturbed communities usually requires that the alien taxon overcomes a different category of barriers.
We propose that the term ‘invasive’ should be used without any inference to environmental or economic impact. Terms like ‘pests’ and ‘weeds’ are suitable labels for the 50–80% of invaders that have harmful effects. About 10% of invasive plants that change the character, condition, form, or nature of ecosystems over substantial areas may be termed ‘transformers’.
Ranunculus is a large genus with a worldwide distribution. Phylogenetic analyses of c. 200 species of Ranunculus s.l. based on sequences of the nrITS using maximum parsimony and Bayesian inference yielded high congruence with previous cpDNA restriction site analyses, but strongly contradict previous classifications. A large core clade including Ranunculus subg. Ranunculus, subg. Batrachium, subg. Crymodes p.p., Ceratocephala, Myosurus, and Aphanostemma is separated from R. subg. Ficaria, subg. Pallasiantha, subg. Coptidium, subg. Crymodes p.p., Halerpestes, Peltocalathos, Callianthemoides, and Arcteranthis. Within the core clade, 19 clades can be described with morphological and karyological features. Several sections are not monophyletic. Parallel evolution of morphological characters in adaptation to climatic conditions may be a reason for incongruence of molecular data and morphology-based classifications. In some mountainous regions, groups of closely related species may have originated from adaptive radiation and rapid speciation. Split decomposition analysis indicated complex patterns of relationship and suggested hybridization in the apomictic R. auricomus complex, R. subg. Batrachium, and the white-flowering European alpines. The evolutionary success of the genus might be due to a combination of morphological plasticity and adaptations, hybridization and polyploidy as important factors for regional diversification, and a broad range of reproductive strategies.
Herbarium handbook. Kew: Royal Botanic Gardens
- D M Bridson
- L Forman
Bridson DM, Forman L. 1998. Herbarium handbook. Kew: Royal Botanic
Gardens.
Native plant community recovery after Carpobrotus (ice plant) removal on an island-results of a 10-year project
- E Buisson
- J Braschi
- J Chenot-Lescure
- Mcm Hess
- C Vidaller
- D Pavon
- H Ramone
- E Cottaz
- C Passetti
Buisson E, Braschi J, Chenot-Lescure J, Hess MCM, Vidaller C, Pavon D,
Ramone H, Amy-Krebs E, Cottaz C, Passetti A, et al. 2021. Native plant
community recovery after Carpobrotus (ice plant) removal on an island-results of a 10-year project. Appl Veg Sci. 24(1):e12524.
Invasive species compendium
- Cabi
CABI. 2021. Invasive species compendium. Wallingford, UK: CABI. www.
cabi.org/isc.
Darjiling hills, West Bengal (India)
- A P Das
Das AP. 2002. Darjiling hills, West Bengal (India). J Econ Taxon Bot.
26(1):31-37.
Diversity and distribution of buttercups (Ranunculus L.) in Kashmir valley of J&K
- F A Lone
- G H Dar
Lone FA, Dar GH. 2016. Diversity and distribution of buttercups
(Ranunculus L.) in Kashmir valley of J&K, India. Pleione. 10(2):209-225.
Plants of the world online
- Powo
POWO. 2019. Plants of the world online. Kew: Royal Botanic Gardens;
[accessed 2021 Aug 2]. http://www.plantsoftheworldonline.org/.
Impacts of erratic snowfall on apple orchards in Kashmir Valley
- I Rashid
- U Majeed
- S Aneaus
- Jab Cánovas
- M Stoffel
- N A Najar
- I A Bhat
- S Lotus
Rashid I, Majeed U, Aneaus S, Cánovas JAB, Stoffel M, Najar NA, Bhat
IA, Lotus S. 2020. Impacts of erratic snowfall on apple orchards in
Kashmir Valley, India. Sustainability. 12(21):9206.