scholarly journals Global distribution and drivers of language extinction risk

2014 ◽  
Vol 281 (1793) ◽  
pp. 20141574 ◽  
Author(s):  
Tatsuya Amano ◽  
Brody Sandel ◽  
Heidi Eager ◽  
Edouard Bulteau ◽  
Jens-Christian Svenning ◽  
...  
Keyword(s):  
Economic Growth ◽  
Extinction Risk ◽  
Small Population ◽  
Global Distribution ◽  
Human Populations ◽  
Small Range ◽  
Geographical Patterns ◽  
Socioeconomic Drivers ◽  
Population Sizes ◽  
The Tropics

Many of the world's languages face serious risk of extinction. Efforts to prevent this cultural loss are severely constrained by a poor understanding of the geographical patterns and drivers of extinction risk. We quantify the global distribution of language extinction risk—represented by small range and speaker population sizes and rapid declines in the number of speakers—and identify the underlying environmental and socioeconomic drivers. We show that both small range and speaker population sizes are associated with rapid declines in speaker numbers, causing 25% of existing languages to be threatened based on criteria used for species. Language range and population sizes are small in tropical and arctic regions, particularly in areas with high rainfall, high topographic heterogeneity and/or rapidly growing human populations. By contrast, recent speaker declines have mainly occurred at high latitudes and are strongly linked to high economic growth. Threatened languages are numerous in the tropics, the Himalayas and northwestern North America. These results indicate that small-population languages remaining in economically developed regions are seriously threatened by continued speaker declines. However, risks of future language losses are especially high in the tropics and in the Himalayas, as these regions harbour many small-population languages and are undergoing rapid economic growth.

Population viability analysis on a native Danish cattle breed

2016 ◽  
Vol 59 ◽  
pp. 105-112 ◽  
Author(s):  
Morten Hertz ◽  
Iben Ravnborg Jensen ◽  
Laura Østergaard Jensen ◽  
Iben Vejrum Nielsen ◽  
Jacob Winde ◽  
...  
Keyword(s):  
Bos Taurus ◽  
Extinction Risk ◽  
Population Viability Analysis ◽  
Cattle Breed ◽  
Population Viability ◽  
Small Population ◽  
Viability Analysis ◽  
Probability Of Survival ◽  
Population Sizes ◽  
Breeding Pool

SummaryMany domestic breeds face challenges concerning genetic variability, because of their small population sizes along with a high risk of inbreeding. Therefore, it is important to obtain knowledge on their extinction risk, along with the possible benefits of certain breeding strategies. Since many domestic breeds face the same problems, results from such studies can be applied across breeds and species. Here a Population Viability Analysis (PVA) was implemented to simulate the future probability of extinction for a population of the endangered Danish Jutland cattle (Bos taurus), based on the software Vortex. A PVA evaluates the extinction risk of a population by including threats and demographic values. According to the results from the PVA the population will go extinct after 122 years with the current management. Four scenarios were created to investigate which changes in the breeding scheme would have the largest effect on the survival probabilities, including Scenario 1: More females in the breeding pool, scenario 2: More males in the breeding pool, scenario 3: Increased carrying capacity, and scenario 4: Supplementing males to the population through artificial insemination using semen from bulls used in the populations in past generations. All scenarios showed a positive effect on the population's probability of survival, and with a combination of the different scenarios, the population size seems to be stabilized.

Biology and conservation of Coptis teeta Wall. – an endemic and endangered medicinal herb of Eastern Himalaya

1998 ◽  
Vol 25 (3) ◽  
pp. 262-272 ◽  
Author(s):  
M. K. PANDIT ◽  
C. R. BABU
Keyword(s):  
Scientific Information ◽  
Small Population ◽  
Vital Role ◽  
Eastern Himalaya ◽  
Evolutionary Divergence ◽  
External Threats ◽  
Population Sizes ◽  
Over Exploitation ◽  
Endangered Medicinal Herb ◽  
The Tropics

Medicinal plants are a valuable resource for regional economic development in the tropics, and the Eastern Himalaya in particular harbours many such species. Extensive deforestation and over-exploitation in this region have brought several species to the brink of extinction, and Coptis teeta is such an endangered species; yet scientific information for its conservation is lacking. Investigations on the distribution range, demography, ecology, cytology, reproductive biology and population genetic structure of C. teeta were carried out; it was found to be endemic to a small area, to occupy a very narrow habitat and to be highly dispersed with very small population sizes. Edaphic factors were found to have played a vital role in ecological preference, natural distribution and evolutionary divergence of the species. The species exhibits a ‘K’ strategy, high male sterility, low reproductive success and efficiency, inadequate seed dispersal, and little genetic variability. A combination of these genetic hurdles and external threats in the form of habitat disturbance and over-exploitation for commercial purposes could result in its extinction. The species was found to have highly specific microsite requirements that cannot be met in other habitats. It is argued that in situ conservation measures would be the best strategy for the continued survival of this species. For effective management of the species it is recommended that its habitat be declared a protected area with the active cooperation of local inhabitants including the sharing of benefits of conservation.

scholarly journals Population extinctions driven by climate change, population size, and time since observation may make rare species databases inaccurate

2018 ◽  
Author(s):  
Thomas Kaye ◽  
Matt A Bahm ◽  
Andrea S Thorpe ◽  
Erin C Gray ◽  
Ian Pfingsten ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Size ◽  
Rare Species ◽  
Biological Diversity ◽  
Extinction Risk ◽  
Climate Change Impacts ◽  
Small Population ◽  
Population Extinction ◽  
Population Sizes ◽  
Potential Signal

Loss of biological diversity through population extinctions is a global phenomenon that threatens many ecosystems. Managers often rely on databases of rare species locations to plan land use actions and conserve at-risk taxa, so it is crucial that the information they contain is accurate and dependable. However, climate change, small population sizes, and long gaps between surveys may be leading to undetected extinctions of many populations. We used repeated survey records for a rare but widespread orchid, Cypripedium fasciculatum (clustered lady's slipper), to model population extinction risk based on elevation, population size, and time between observations. Population size was negatively associated with extinction, while elevation and time between observations interacted such that low elevation populations were most vulnerable to extinction, but only over larger time spans. We interpret population losses at low elevations as a potential signal of climate change impacts. We used this model to estimate the probability of persistence of populations across California and Oregon, and found that 31%-56% of the 2415 populations reported in databases from this region are likely extinct. Managers should be aware that the number of populations of rare species in their databases is potentially an overestimate, and consider resurveying these populations to document their presence and condition, with priority given to older reports of small populations, especially those at low elevations or in other areas with high climate vulnerability.

scholarly journals The Last Two Remaining Populations of the Critically Endangered Estuarine Pipefish Are Inbred and Not Genetically Distinct

2022 ◽  
Vol 8 ◽  
Author(s):  
Sven-Erick Weiss ◽  
Arsalan Emami-Khoyi ◽  
Horst Kaiser ◽  
Paul D. Cowley ◽  
Nicola C. James ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Extinction Risk ◽  
Significant Risk ◽  
Small Population ◽  
Environmental Stochasticity ◽  
Critically Endangered ◽  
Conservation Strategy ◽  
Genome Wide Data ◽  
Significant Genetic Structure ◽  
Population Sizes

The critically endangered estuarine pipefish, Syngnathus watermeyeri, is one of Africa’s rarest fish species and currently faces a significant risk of extinction. A combination of anthropogenic and natural factors threaten submerged macrophyte beds in the two South African estuaries (Bushmans and Kariega) in which the species’ only two known remaining populations reside. Here, we genotyped 34 pipefish from both populations using genome-wide data to determine whether the two estuaries harbour distinct genetic diversity, such that translocating individuals between them might improve the genetic health of both. Our results show that both populations are highly inbred, and no statistically significant genetic structure was found between them. Moreover, individuals both within and between estuaries were very closely related to each other. These results indicate that the remaining populations of the estuarine pipefish suffer from the adverse genetic effects of small population sizes. Even though recent surveys have estimated population sizes in the order of thousands of individuals, these may fluctuate considerably. Although the translocation of genetically similar individuals between habitats will not increase local genetic diversity, the creation of additional populations across the species’ historical range may be a suitable conservation strategy to prevent further loss of genetic diversity, and to minimise the overall extinction risk posed by environmental stochasticity.

Conservation translocation – an increasingly viable option for managing threatened plant species

2019 ◽  
Vol 67 (7) ◽  
pp. 501 ◽  
Author(s):  
Heidi C. Zimmer ◽  
Tony D. Auld ◽  
Peter Cuneo ◽  
Catherine A. Offord ◽  
Lucy E. Commander
Keyword(s):  
Plant Species ◽  
Extinction Risk ◽  
Small Population ◽  
Viable Option ◽  
Threatened Plants ◽  
Threatened Plant ◽  
Management Actions ◽  
Threatened Plant Species ◽  
Population Sizes ◽  
Extinction Risk Assessment

Translocation is the establishment and augmentation of plant populations using ex situ material, and can reduce extinction risk. Historically, translocation has been considered to be high cost and high risk, but today, translocation is increasingly recognised as a necessary option for managing many threatened plant species. To examine the viability of translocation as a management action, we analysed the frequency of it being a recommended management action, its estimated cost over time, and its perceived likelihood of success as compared with other management actions. We did this using the 368 threatened plant species in the New South Wales state register of threatened species management strategies (the Saving our Species (SOS) database). Translocation was recommended as a management action for 30% of threatened plants (112 species), mostly in response to demographic threats (i.e. threats affecting species with small population sizes/restricted distributions, for example, environmental and demographic stochasticity or low genetic diversity). The estimated cost of translocation per species was similar to other common management actions. However, expert elicitation data (in the SoS database) indicated that translocation was less certain of a beneficial outcome, compared with almost all other management actions. Based on these findings, we create a decision framework, which uses the principles of extinction risk assessment to assist conservation managers in determining when translocation is most likely to be beneficial. We suggest that the use of translocation to mitigate the risk of extinction associated with small population sizes/restricted ranges is supported by the principles of extinction risk assessment. With a growing knowledge base, and costs comparable to other management actions, translocation is becoming an increasingly viable option for the conservation management of threatened plants, provided best practice guidelines are followed.

scholarly journals Range size dynamics can explain why evolutionarily age and diversification rate correlate with contemporary extinction risk in plants

2017 ◽  
Author(s):  
Andrew J. Tanentzap ◽  
Javier Igea ◽  
Matthew G. Johnston ◽  
Matthew J. Larcombe
Keyword(s):  
Biodiversity Conservation ◽  
Extinction Risk ◽  
Range Size ◽  
Potential Range ◽  
Small Range ◽  
Conifer Species ◽  
Diversification Rates ◽  
Age Dependent ◽  
Threatened Taxa ◽  
Population Sizes

AbstractExtinction threatens many species, yet few factors predict this risk across the plant Tree of Life (ToL). Taxon age is one factor that may associate with extinction if occupancy of geographic and adaptive zones varies with time, but evidence for such an association has been equivocal. Age-dependent occupancy can also influence diversification rates and thus extinction risk where new taxa have small range and population sizes. Here we analysed 509 well-sampled genera from across the plant ToL. We found that a greater proportion of species were threatened by extinction in younger and faster-diversifying genera. Repeating our analyses in two large, well-sampled groups, we found that extinction risk increased with evolutionary age in conifer species but not palms. Potential range size decreased in older, non-threatened conifers more strongly than in threatened taxa, suggesting that range size dynamics may explain differing patterns of extinction risk across the ToL with consequences for biodiversity conservation.

scholarly journals Fern diversity and distribution in the UBD campus

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Daniele Cicuzza ◽  
Muhammad Adib Hidayatullah Ahmad ◽  
Ahmad Rafi’uddin Bin Jipli ◽  
Dk Noorul Suhailah Binti Pg Sapudin ◽  
Nor Syukriah Akmal Bte Awg Hj Ismail
Keyword(s):  
Small Population ◽  
Forest Fragments ◽  
Infrastructure Development ◽  
Brunei Darussalam ◽  
Forested Areas ◽  
Population Sizes ◽  
Conservation Projects ◽  
The Tropics ◽  
Flora Diversity ◽  
Small Forest

Green areas and parks are important for maintaining local biodiversity in urbanised habitats. Recent studies have demonstrated that the biodiversity retained in these areas is also important for engaging citizen scientists in conservation projects. Most of the documentation on biodiversity is from temperate regions, whereas in the tropics this field is still in its infancy. This study documented the fern and fern allies richness and abundance within the Universiti Brunei Darussalam (UBD) campus, Brunei Darussalam. We found 39 species in total, belonging to 20 families and 28 genera. Although the total richness did not differ between forest and open plots, ordination showed that forested areas retained a different species composition. Although none of the identified species were IUCN listed, nearly half of the species were recorded once or twice, indicating small population sizes and the biological value of small forest fragments. Our study contributes to understanding the flora diversity of the UBD campus. These results can be used to minimise environmental degradation during infrastructure development on the UBD campus.

scholarly journals Eco-evolutionary feedbacks, adaptive dynamics and evolutionary rescue theory

2013 ◽  
Vol 368 (1610) ◽  
pp. 20120081 ◽  
Author(s):  
Regis Ferriere ◽  
Stéphane Legendre
Keyword(s):  
Extinction Risk ◽  
Adaptive Dynamics ◽  
Population Viability ◽  
Small Population ◽  
Adaptive Process ◽  
Evolutionary Rescue ◽  
The Face ◽  
Population Sizes ◽  
Evolutionary Suicide ◽  
Dynamics Models

Adaptive dynamics theory has been devised to account for feedbacks between ecological and evolutionary processes. Doing so opens new dimensions to and raises new challenges about evolutionary rescue. Adaptive dynamics theory predicts that successive trait substitutions driven by eco-evolutionary feedbacks can gradually erode population size or growth rate, thus potentially raising the extinction risk. Even a single trait substitution can suffice to degrade population viability drastically at once and cause ‘evolutionary suicide’. In a changing environment, a population may track a viable evolutionary attractor that leads to evolutionary suicide, a phenomenon called ‘evolutionary trapping’. Evolutionary trapping and suicide are commonly observed in adaptive dynamics models in which the smooth variation of traits causes catastrophic changes in ecological state. In the face of trapping and suicide, evolutionary rescue requires that the population overcome evolutionary threats generated by the adaptive process itself. Evolutionary repellors play an important role in determining how variation in environmental conditions correlates with the occurrence of evolutionary trapping and suicide, and what evolutionary pathways rescue may follow. In contrast with standard predictions of evolutionary rescue theory, low genetic variation may attenuate the threat of evolutionary suicide and small population sizes may facilitate escape from evolutionary traps.

Estimating the exposure of carnivorous plants to rapid climatic change

2018 ◽  
Author(s):  
Matthew C. Fitzpatrick ◽  
Aaron M. Ellison
Keyword(s):  
Climatic Change ◽  
Habitat Suitability ◽  
Species Distributions ◽  
Dispersal Limitation ◽  
Small Population ◽  
Carnivorous Plant ◽  
Carnivorous Plants ◽  
Habitat Specialization ◽  
Population Sizes ◽  
Suitable Habitats

Climatic change likely will exacerbate current threats to carnivorous plants. However, estimating the severity of climatic change is challenged by the unique ecology of carnivorous plants, including habitat specialization, dispersal limitation, small ranges, and small population sizes. We discuss and apply methods for modeling species distributions to overcome these challenges and quantify the vulnerability of carnivorous plants to rapid climatic change. Results suggest that climatic change will reduce habitat suitability for most carnivorous plants. Models also project increases in habitat suitability for many species, but the extent to which these increases may offset habitat losses will depend on whether individuals can disperse to and establish in newly suitable habitats outside of their current distribution. Reducing existing stressors and protecting habitats where numerous carnivorous plant species occur may ameliorate impacts of climatic change on this unique group of plants.

scholarly journals Biological and extrinsic correlates of extinction risk in Chinese lizards

2021 ◽  
Author(s):  
Yuxi Zhong ◽  
Chuanwu Chen ◽  
Yanping Wang
Keyword(s):  
Body Size ◽  
Extinction Risk ◽  
Species Traits ◽  
Geographic Range ◽  
Range Size ◽  
Habitat Specialization ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Small Range ◽  
Extrinsic Factors

Abstract China is a country with one of the most species rich reptile faunas in the world. However, nearly a quarter of Chinese lizard species assessed by the China Biodiversity Red List are threatened. Nevertheless, to date, no study has explicitly examined the pattern and processes of extinction and threat in Chinese lizards. In this study, we conducted the first comparative phylogenetic analysis of extinction risk in Chinese lizards. We addressed the following three questions: 1) What is the pattern of extinction and threat in Chinese lizards? 2) Which species traits and extrinsic factors are related to their extinction risk? 3) How can we protect Chinese lizards based on our results? We collected data on ten species traits (body size, clutch size, geographic range size, activity time, reproductive mode, habitat specialization, habitat use, leg development, maximum elevation, and elevation range) and seven extrinsic factors (mean annual precipitation, mean annual temperature, mean annual solar insolation, normalized difference vegetation index (NDVI), human footprint, human population density, and human exploitation). After phylogenetic correction, these variables were used separately and in combination to assess their associations with extinction risk. We found that Chinese lizards with small geographic range, large body size, high habitat specialization, and living in high precipitation areas were vulnerable to extinction. Conservation priority should thus be given to species with the above extinction-prone traits so as to effectively protect Chinese lizards. Preventing future habitat destruction should also be a primary focus of management efforts because species with small range size and high habitat specialization are particularly vulnerable to habitat loss.

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