scholarly journals Historical and current distribution ranges and loss of mega-herbivores and carnivores of Asia

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10738
Author(s):  
Tariq Mahmood ◽  
Tuong Thuy Vu ◽  
Ahimsa Campos-Arceiz ◽  
Faraz Akrim ◽  
Shaista Andleeb ◽  
...  
Keyword(s):  
Current Distribution ◽  
Ecosystem Functioning ◽  
Human Impacts ◽  
Spatially Explicit ◽  
Large Mammals ◽  
Southwest Asia ◽  
Conservation Policies ◽  
Asiatic Lion ◽  
Distribution Ranges ◽  
Historical Distribution

Ecosystem functioning is dependent a lot on large mammals, which are, however, vulnerable and facing extinction risks due to human impacts mainly. Megafauna of Asia has been declining for a long, not only in numbers but also in their distribution ranges. In the current study, we collected information on past and current occurrence and distribution records of Asia’s megafauna species. We reconstructed the historical distribution ranges of the six herbivores and four carnivores for comparison with their present ranges, to quantify spatially explicit levels of mega-defaunation. Results revealed that historically the selected megafauna species were more widely distributed than at current. Severe range contraction was observed for the Asiatic lion, three rhino species, Asian elephant, tigers, and tapirs. Defaunation maps generated have revealed the vanishing of megafauna from parts of the East, Southeast, and Southwest Asia, even some protected Areas losing up to eight out of ten megafaunal species. These defaunation maps can help develop future conservation policies, to save the remaining distribution ranges of large mammals.

scholarly journals Impacts of Land-Use Changes on Vegetation and Ecosystem Functioning: Old-Field Secondary Succession

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 990
Author(s):  
Javier Pérez-Hernández ◽  
Rosario G. Gavilán
Keyword(s):  
Plant Communities ◽  
Ecosystem Functioning ◽  
Secondary Succession ◽  
Species Coexistence ◽  
Human Impacts ◽  
Soil Seed Bank ◽  
Land Use Changes ◽  
Dispersal Limitation ◽  
Point Of View ◽  
Old Field

The study of ecological succession to determine how plant communities re-assemble after a natural or anthropogenic disturbance has always been an important topic in ecology. The understanding of these processes forms part of the new theories of community assembly and species coexistence, and is attracting attention in a context of expanding human impacts. Specifically, new successional studies provide answers to different mechanisms of community assemblage, and aim to define the importance of deterministic or stochastic processes in the succession dynamic. Biotic limits, which depend directly on biodiversity (i.e., species competition), and abiotic filtering, which depends on the environment, become particularly important when they are exceeded, making the succession process more complicated to reach the previous disturbance stage. Plant functional traits (PFTs) are used in secondary succession studies to establish differences between abandonment stages or to compare types of vegetation or flora, and are more closely related to the functioning of plant communities. Dispersal limitation is a PFT considered an important process from a stochastic point of view because it is related to the establishing of plants. Related to it the soil seed bank plays an important role in secondary succession because it is essential for ecosystem functioning. Soil compounds and microbial community are important variables to take into account when studying any succession stage. Chronosequence is the best way to study the whole process at different time scales. Finally, our objective in this review is to show how past studies and new insights are being incorporated into the basis of classic succession. To further explore this subject we have chosen old-field recovery as an example of how a number of different plant communities, including annual and perennial grasslands and shrublands, play an important role in secondary succession.

Did prehistoric landscape management retard the post-glacial spread of woodland in Southwest Asia?

Antiquity ◽  
2002 ◽  
Vol 76 (294) ◽  
pp. 1002-1010 ◽  
Author(s):  
Neil Roberts
Keyword(s):  
Bronze Age ◽  
Human Impacts ◽  
Landscape Management ◽  
Southwest Asia ◽  
Mediterranean Environment ◽  
East Mediterranean ◽  
Late Season ◽  
Pollen Diagrams ◽  
New Evidence ◽  
Trees And Shrubs

Pre-Bronze Age human impacts on the East Mediterranean environment have been hard to detect in pollen diagrams and other off-site contexts. New evidence shows that despite a relatively rapid post-glacial wetting-up of the climate, the re-advance of oak woodland across Southwest Asia was slow. Among the factors likely to have contributed to the apparent disjunction between climate and vegetation is Neolithic landscape management, particularly through regular use of late-season ground fires to encourage grasses at the expense of trees and shrubs.

scholarly journals Climate warming and humans played different roles in triggering Late Quaternary extinctions in east and west Eurasia

2017 ◽  
Vol 284 (1851) ◽  
pp. 20162438 ◽  
Author(s):  
Xinru Wan ◽  
Zhibin Zhang
Keyword(s):  
Climate Change ◽  
Late Pleistocene ◽  
Climate Warming ◽  
Human Impacts ◽  
Late Quaternary ◽  
Extinction Risk ◽  
Early Holocene ◽  
Large Mammals ◽  
Predominant Factor ◽  
Late Pleistocene To Holocene

Climate change and humans are proposed as the two key drivers of total extinction of many large mammals in the Late Pleistocene and Early Holocene, but disentangling their relative roles remains challenging owing to a lack of quantitative evaluation of human impact and climate-driven distribution changes on the extinctions of these large mammals in a continuous temporal–spatial dimension. Here, our analyses showed that temperature change had significant effects on mammoth (genus Mammuthus ), rhinoceros (Rhinocerotidae), horse (Equidae) and deer (Cervidae). Rapid global warming was the predominant factor driving the total extinction of mammoths and rhinos in frigid zones from the Late Pleistocene and Early Holocene. Humans showed significant, negative effects on extirpations of the four mammalian taxa, and were the predominant factor causing the extinction or major extirpations of rhinos and horses. Deer survived both rapid climate warming and extensive human impacts. Our study indicates that both the current rates of warming and range shifts of species are much faster than those from the Late Pleistocene to Holocene. Our results provide new insight into the extinction of Late Quaternary megafauna by demonstrating taxon-, period- and region-specific differences in extinction drivers of climate change and human disturbances, and some implications about the extinction risk of animals by recent and ongoing climate warming.

scholarly journals The future of seagrass meadows

2002 ◽  
Vol 29 (2) ◽  
pp. 192-206 ◽  
Author(s):  
Carlos M. Duarte
Keyword(s):  
Human Impacts ◽  
Marine Ecosystem ◽  
Monitoring Network ◽  
Global Ocean ◽  
Major Barrier ◽  
Tropical Regions ◽  
Conservation Policies ◽  
Positive Effects ◽  
Seagrass Meadows ◽  
The Future

Seagrasses cover about 0.1–0.2% of the global ocean, and develop highly productive ecosystems which fulfil a key role in the coastal ecosystem. Widespread seagrass loss results from direct human impacts, including mechanical damage (by dredging, fishing, and anchoring), eutrophication, aquaculture, siltation, effects of coastal constructions, and food web alterations; and indirect human impacts, including negative effects of climate change (erosion by rising sea level, increased storms, increased ultraviolet irradiance), as well as from natural causes, such as cyclones and floods. The present review summarizes such threats and trends and considers likely changes to the 2025 time horizon. Present losses are expected to accelerate, particularly in South-east Asia and the Caribbean, as human pressure on the coastal zone grows. Positive human effects include increased legislation to protect seagrass, increased protection of coastal ecosystems, and enhanced efforts to monitor and restore the marine ecosystem. However, these positive effects are unlikely to balance the negative impacts, which are expected to be particularly prominent in developing tropical regions, where the capacity to implement conservation policies is limited. Uncertainties as to the present loss rate, derived from the paucity of coherent monitoring programmes, and the present inability to formulate reliable predictions as to the future rate of loss, represent a major barrier to the formulation of global conservation policies. Three key actions are needed to ensure the effective conservation of seagrass ecosystems: (1) the development of a coherent worldwide monitoring network, (2) the development of quantitative models predicting the responses of seagrasses to disturbance, and (3) the education of the public on the functions of seagrass meadows and the impacts of human activity.

scholarly journals Bycatch mitigation could prevent strong changes in the ecological strategies of seabird communities across the globe

2021 ◽  
Author(s):  
Cerren Richards ◽  
Robert S. C. Cooke ◽  
Diana E. Bowler ◽  
Kristina Boerder ◽  
Amanda E. Bates
Keyword(s):  
Spatial Variation ◽  
Ecosystem Functioning ◽  
Species Traits ◽  
Fishing Effort ◽  
Population Declines ◽  
Ecological Strategies ◽  
Mass Generation ◽  
Management Actions ◽  
Distribution Ranges ◽  
Fisheries Bycatch

Fisheries bycatch, the incidental mortality of non-target species, is a major threat to seabirds worldwide. Mitigating bycatch is an important factor to reduce seabird population declines and consequent changes in ocean trophic dynamics and ecosystem functioning. However, it remains an open question how and where mitigating bycatch at a global scale may conserve seabird traits and the ecological strategies that traits represent. Here we combine a dataset of species traits and distribution ranges for 341 seabirds with spatially resolved fishing effort data for gillnet, longline, trawl, and purse seine gears to: (1) understand spatial variation in seabird community traits; and (2) test whether mitigating fisheries bycatch may prevent shifts in traits of seabird communities and loss of ecological strategies. We find distinct spatial variation in the community weighted mean of five seabird traits (clutch size, body mass, generation length, foraging guild, and diet guild). Furthermore, our analysis suggests that successful bycatch mitigation could prevent strong shifts in the traits of seabird communities across the globe particularly in the North Atlantic and Southern Oceans. Specifically, changes in dominant foraging and diet guilds, and shifts towards communities with faster reproductive speeds (larger clutch sizes and shorter generation lengths) and smaller body masses could be avoided. Therefore, bycatch mitigation may have important indirect benefits for sustaining ecosystem functioning, as mediated by species traits. Incorporating species traits into management actions will provide valuable tools for marine spatial planning and when evaluating the success of conservation initiatives.

scholarly journals Distribution of mountain hawkweeds (Hieracium s. str.) in the Hrubý Jeseník Mountains

2017 ◽  
Vol 66 (3) ◽  
pp. 193-229
Author(s):  
Jiří Kocián ◽  
Jindřich Chrtek
Keyword(s):  
Population Size ◽  
Current Distribution ◽  
Factors Influencing ◽  
Historical Distribution ◽  
New Localities ◽  
Field Revision

Abstract Field revision of current distribution of mountain hawkweeds (Hieracium s. str.) in the Hrubý Jeseník Mts was undertaken. Hieracium atratum, H. chlorocephalum, H. engleri, H. grabowskianum and H. plumbeum, whose last occurrence was documented many decades or even a century ago, were rediscovered. H. plumbeum was even found in new localities. The occurrence of H. alpinum, H. bifidum, H. chrysostyloides, H. inuloides, H. nigritum, H. prenanthoides, H. silesiacum, H. stygium and H. villosum was ascertained at many of their historical localities and a few new localities were found too. A neophyte species H. mixtum was discovered. Hieracium moravicum was not found. Accurate locality description and population size are provided for each finding. Herbarium revision and excerption of crucial literature were performed to provide historical distribution. Distributional changes as well as threatening and beneficial factors influencing Hieracium species in the Hrubý Jeseník Mts are discussed.

scholarly journals Global mycorrhizal plant distribution linked to terrestrial carbon stocks

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Nadejda A. Soudzilovskaia ◽  
Peter M. van Bodegom ◽  
César Terrer ◽  
Maarten van’t Zelfde ◽  
Ian McCallum ◽  
...  
Keyword(s):  
Ecosystem Functioning ◽  
Carbon Stocks ◽  
Plant Distribution ◽  
Spatially Explicit ◽  
Mycorrhizal Plant ◽  
Terrestrial Carbon ◽  
Mycorrhizal Associations ◽  
Soil Carbon Stocks ◽  
Quantitative Analyses ◽  
Fungal Associations

Abstract Vegetation impacts on ecosystem functioning are mediated by mycorrhizas, plant–fungal associations formed by most plant species. Ecosystems dominated by distinct mycorrhizal types differ strongly in their biogeochemistry. Quantitative analyses of mycorrhizal impacts on ecosystem functioning are hindered by the scarcity of information on mycorrhizal distributions. Here we present global, high-resolution maps of vegetation biomass distribution by dominant mycorrhizal associations. Arbuscular, ectomycorrhizal, and ericoid mycorrhizal vegetation store, respectively, 241 ± 15, 100 ± 17, and 7 ± 1.8 GT carbon in aboveground biomass, whereas non-mycorrhizal vegetation stores 29 ± 5.5 GT carbon. Soil carbon stocks in both topsoil and subsoil are positively related to the community-level biomass fraction of ectomycorrhizal plants, though the strength of this relationship varies across biomes. We show that human-induced transformations of Earth’s ecosystems have reduced ectomycorrhizal vegetation, with potential ramifications to terrestrial carbon stocks. Our work provides a benchmark for spatially explicit and globally quantitative assessments of mycorrhizal impacts on ecosystem functioning and biogeochemical cycling.

Genetically defining populations is of limited use for evaluating and managing human impacts on gene flow

2012 ◽  
Vol 39 (4) ◽  
pp. 290 ◽  
Author(s):  
Adam J. Stow ◽  
William E. Magnusson
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Human Impacts ◽  
Statistical Tests ◽  
In Situ Conservation ◽  
Spatially Explicit ◽  
Genetic Studies ◽  
Genetic Detection ◽  
Sampling Procedures

Partitioning genetic variation into panmictic units is one of the most commonly used techniques in genetic studies of wild organisms. For conservation, the rationale is to identify units for management, most often referred to as populations. Describing these populations provides a measure of genetic differentiation, but they are only management units in relation to specific objectives. In situ conservation activities are mostly constrained to landscape (or ‘seascape’) units. With continuing habitat fragmentation, maintaining gene flow and genetic variation is an underlying objective for many conservation activities. Spatially explicit genetic approaches can describe how gene flow varies across a landscape, but the popular approach of identifying populations has limited and specific application. The statistical tests and sampling procedures used seldom allow for the spatial extent of genetic panmixia to be precisely defined. Gene flow, genetic variation and genetic detection of individual movements can be estimated without reference to populations. Furthermore, the term ‘population’ is used inconsistently in the literature and is often poorly defined. Formulating appropriate questions for management requires that the unit of study is clearly described, and often this could be organisms inhabiting defined areas of the landscape. Resources for conservation management are limited, so geneticists working on gene flow in wild organisms need to frame questions relevant to specific management needs and carefully consider the language and approaches employed.

scholarly journals Where Might We Find Ecologically Intact Communities?

2021 ◽  
Vol 4 ◽  
Author(s):  
Andrew J. Plumptre ◽  
Daniele Baisero ◽  
R. Travis Belote ◽  
Ella Vázquez-Domínguez ◽  
Soren Faurby ◽  
...  
Keyword(s):  
Land Surface ◽  
Human Impacts ◽  
Ecological Integrity ◽  
Initial Assessment ◽  
Distribution Data ◽  
Species Loss ◽  
Large Mammals ◽  
Human Footprint ◽  
The World ◽  
A Site

Conservation efforts should target the few remaining areas of the world that represent outstanding examples of ecological integrity and aim to restore ecological integrity to a much broader area of the world with intact habitat and minimal species loss while this is still possible. There have been many assessments of “intactness” in recent years but most of these use measures of anthropogenic impact at a site, rather than faunal intactness or ecological integrity. This paper makes the first assessment of faunal intactness for the global terrestrial land surface and assesses how many ecoregions have sites that could qualify as Key Biodiversity Areas (KBAs – sites contributing significantly to the global persistence of biodiversity) based on their outstanding ecological integrity (under KBA Criterion C). Three datasets are combined on species loss at sites to create a new spatially explicit map of numbers of species extirpated. Based on this map it is estimated that no more than 2.9% of the land surface can be considered to be faunally intact. Additionally, using habitat/density distribution data for 15 large mammals we also make an initial assessment of areas where mammal densities are reduced, showing a further decrease in surface area to 2.8% of the land surface that could be considered functionally intact. Only 11% of the functionally intact areas that were identified are included within existing protected areas, and only 4% within existing KBAs triggered by other criteria. Our findings show that the number of ecoregions that could qualify as Criterion C KBAs could potentially increase land area up to 20% if their faunal composition was restored with the reintroduction of 1–5 species. Hence, if all necessary requirements are met in order to reintroduce species and regain faunal integrity, this will increase ecological integrity across much of the area where human impacts are low (human footprint ≤4). Focusing restoration efforts in these areas could significantly increase the area of the planet with full ecological integrity.

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