The influence of environmental factors on the dynamics of the size and spatial structure of the chamois (Rupicapra rupicapra caucasica) population on the Caucasian Reserve

The size and structure of the chamois (Rupicapra rupicapra caucasica) population as well as the influence of anthropogenic factors on it were studied on the Caucasian Reserve (Western Caucasus). The negative effect of the snow cover, the thickness of which differed from the usual level, is shown. The effect of winters with thick snow cover is confirmed by the relation between these factors and the proportion of yearlings in the population one year after the winter. An increased death rate of animals in winters with a deep snow cover is observed in the case when their density exceeds the optimal one. Wolf predation does not affect the chamois population on the reserve. The number of wolves increases with an increase in the chamois population density to 15–20 ind./1000 ha. The adverse impact of humans on the chamois population is manifested in the regions with motor roads. The chamois, as compared to the deer, suffers from poachers to a lesser degree because it inhabits inaccessible areas and its trophy value is low.     

Influence of environmental factors on number dynamics and spatial structure of the tur (Capra caucasica) population in the Caucasian Reserve

The number and structure of the tur (Capra caucasica Guldenstaedt et Pallas 1783) population on the territory of Caucasian Reserve (Western Caucasus), as well as peculiarities of the effect of natural and anthropogenic factors on the population, were studied based on ideas of meta-population species dynamics. Fourteen local tur groupings were united into three groups by the similarity of long-term number dynamics. A negative effect of winter, which deviated from the average long-term winter by the level of snowiness, on the tur population was detected. Snowy winters damage not only males (that frequently die in avalanches), but also affect the birth rate subsequently; the portion of females, in spite of the male death, decreases anyway two years after winter, as well as the portion of underyearlings. It was demonstrated that the snowy winter effect is manifested only when the animal density is rather high. The following tendency was detected for the tur population: the greater the density before the winter, the larger the decrease in the animal density after it (and this tendency weakens one year after the winter). Wolf predation has no negative effect on the tur population in the reserve. A maximal association between the tur density and wolf density was found at a tur density up to 50 individuals/1000 hectares. With a further increase in the victim density, the wolf density changes independently of the tur density. Turs in the reserve are not easily accessible to poachers due to habitat peculiarities, and therefore, the role of poaching in the dynamics of their numbers is not significant.     

Assessing the Effects of Multiple Stressors on the Recruitment of Fruit Harvested Trees in a Tropical Dry Forest,Western Ghats,India

The harvest of non-timber forest products (NTFPs), together with other sources of anthropogenic disturbance, impact plant populations greatly. Despite this, conservation research on NTFPs typically focuses on harvest alone, ignoring possible confounding effects of other anthropogenic and ecological factors. Disentangling anthropogenic disturbances is critical in regions such as India’s Western Ghats, a biodiversity hotspot with high human density. Identifying strategies that permit both use and conservation of resources is essential to preserving biodiversity while meeting local needs. We assessed the effects of NTFP harvesting (fruit harvest from canopy and lopping of branches for fruit) in combination with other common anthropogenic disturbances (cattle grazing, fire frequency and distance from village), in order to identify which stressors have greater effects on recruitment of three tropical dry forest fruit tree species. Specifically, we assessed the structure of 54 populations of Phyllanthus emblica, P. indofischeri and Terminalia chebula spread across the Nilgiri Biosphere Reserve, Western Ghats to ask: (1) How are populations recruiting? and (2) What anthropogenic disturbance and environmental factors, specifically forest type and elevation, are the most important predictors of recruitment status? We combined participatory research with an information-theoretic model-averaging approach to determine which factors most affect population structure and recruitment status. Our models illustrate that for T. chebula, high fire frequency and high fruit harvest intensity decreased the proportion of saplings, while lopping branches or stems to obtain fruit increased it. For Phyllanthus spp, recruitment was significantly lower in plots with more frequent fire. Indices of recruitment of both species were significantly higher for plots in more open-canopy environments of savanna woodlands than in dry forests. Our research illustrates an approach for identifying which factors are most important in limiting recruitment of NTFP populations and other plant species that may be in decline, in order to design effective management strategies.     

Environmental factors affecting population level genetic divergence of the striped field mouse (<Emphasis Type="Italic">Apodemus agrarius</Emphasis>) in South Korea

The cognizing of connectivity among small mammal populations across heterogeneous landscapes is complicated due to complex influences of landscape and anthropogenic factors on gene flow. A landscape genetics approach offers inferences on how landscape features drive population structure. Through a landscape genetics approach, we investigated influences of geographical, environmental, and anthropogenic features on populations of Apodemus agrarius, the striped field mouse, the prime vector of hemorrhagic fever by a landscape genetic approach. We identified landscape features that might affect the population structure of striped field mice by analyzing microsatellite markers of 197 striped field mice from 21 populations throughout South Korea. We developed Maximum-likelihood population effects models based on landscape distances and resistance matrices and pairwise F_ST values for meta-populations of striped field mouse. We also conducted Mantel and partial Mantel tests to investigate geographic patterns of genetic similarities. In Mantel and partial Mantel tests, the F_ST was significantly correlated with all three models of movement; movement cost, Euclidian distance and least-cost distance, although the magnitudes of correlations varied. The 4 top-ranked models included three variables; temperature, precipitation and one human disturbance factor (population). We did not attain a significant effect for anthropogenic factors on genetic similarities among populations in the Korean striped field mouse, but we confirmed a significant association for genetic similarity with climatic features (temperature and precipitation).     

人为干扰对乌海市四合木小灌木景观的影响

以乌海市四合木(Tetraena mongolica Maxim)为研究对象,利用2009年Quickbird高分辨率影像,结合四合木群落野外调查数据,对乌海市四合木分布区在不同人为干扰强度下的景观格局和群落进行研究。结果表明:人为干扰越强烈,四合木生境破碎化程度越严重。在植株生理年龄相近,生境相同时,四合木的高度、冠幅以及重要值随人为干扰加剧,变化趋势明显。受人为干扰程度越强地区,其物种丰富度指数越小,生物多样性越低。干扰强度发生变化时,Pielou均匀度指数均在0.77—0.90间。     

Genetic structure as a response to anthropogenic and extreme weather disturbances of a coastal dune dwelling spider,Arctosa sanctaerosae

The continued increase in the number of tourists visiting the Northern Gulf Coast (NGC), USA, in the last century, and the resulting sprawl of large cities along the coast, has degraded and fragmented the available habitat of Arctosa sanctaerosae, a wolf spider endemic to the secondary dunes of the white sandy beaches of the NGC. In addition to anthropogenic disturbance to this coastal region, hurricanes are an additional and natural perturbation to the ecosystem. The data presented here explore the status of populations of this species spanning the entire known range and the factors influencing population demography including anthropogenic disturbance and severe tropical storms. Using microsatellite markers, we were able to document the genetic structure of A. sanctaerosae, including current and historic patterns of migration. These results combined with ecological and census data reveal the characteristics that have influenced population persistence: ecological variables affecting the recovery of the population clusters after severe tropical storms, genetic fragmentation due to anthropogenic disturbance, and their interaction. These findings demonstrate the significance that the high traffic beach communities of the NGC and their impact on the once intact contiguous dune ecosystem have on recovery after severe tropical storms. Contemporary modeling methods that compare current and historic levels of gene flow suggest A. sanctaerosae has experienced a single, contiguous population subdivision, and the isolates reduced in size since the onset of commercial development of the NGC. These results point to the need for monitoring of the species and increased protection for this endangered habitat.     

Patterns of Deep-Sea Genetic Connectivity in the New Zealand Region: Implications for Management of Benthic Ecosystems

Patterns of genetic connectivity are increasingly considered in the design of marine protected areas (MPAs) in both shallow and deep water. In the New Zealand Exclusive Economic Zone (EEZ), deep-sea communities at upper bathyal depths (<2000 m) are vulnerable to anthropogenic disturbance from fishing and potential mining operations. Currently, patterns of genetic connectivity among deep-sea populations throughout New Zealand’s EEZ are not well understood. Using the mitochondrial Cytochrome Oxidase I and 16S rRNA genes as genetic markers, this study aimed to elucidate patterns of genetic connectivity among populations of two common benthic invertebrates with contrasting life history strategies. Populations of the squat lobster Munida gracilis and the polychaete Hyalinoecia longibranchiata were sampled from continental slope, seamount, and offshore rise habitats on the Chatham Rise, Hikurangi Margin, and Challenger Plateau. For the polychaete, significant population structure was detected among distinct populations on the Chatham Rise, the Hikurangi Margin, and the Challenger Plateau. Significant genetic differences existed between slope and seamount populations on the Hikurangi Margin, as did evidence of population differentiation between the northeast and southwest parts of the Chatham Rise. In contrast, no significant population structure was detected across the study area for the squat lobster. Patterns of genetic connectivity in Hyalinoecia longibranchiata are likely influenced by a number of factors including current regimes that operate on varying spatial and temporal scales to produce potential barriers to dispersal. The striking difference in population structure between species can be attributed to differences in life history strategies. The results of this study are discussed in the context of existing conservation areas that are intended to manage anthropogenic threats to deep-sea benthic communities in the New Zealand region.     

Characterization of copepod Scottomyzon gibberum scott population on Asterias rubens L. starfishes under different anthropogenic load conditions

This articles describes copepod Scottomyzon gibberum population on Asterias rubens starfishes collected during the 2012 growth period. The population increases from mid-June to late September. Heterogeneity in the population was also shown, which can be related with anthropogenic load. The population of copepods on the starfishes is higher in regions with increased anthropogenic load conditions. An increase in the copepods population on the starfishes with depth was observed.     

Influence of Holocene environmental change and anthropogenic impact on the diversity and distribution of roe deer

Extant patterns of population structure and levels of diversity are a consequence of factors that vary in both space and time. Our objective in this study is to investigate a species that has responded to both natural and anthropogenic changes in ways that have shaped modern populations and provide insight into the key processes. The roe deer (Capreolus capreolus) is one of the two species of deer native to Britain. During the last glacial maximum (LGM), the British habitat was largely under ice and there was a land bridge to mainland Europe. As the Earth warmed during the early Holocene, the land bridge was lost. Subsequent hunting on the British mainland left the southern region extirpated of roe deer, whereas a refugial population remained in the north. Later reintroductions from Europe led to population expansion, especially in southern United Kingdom. Here, we combine data from ancient and modern DNA to track population dynamics and patterns of connectivity, and test hypotheses about the influence of natural and anthropogenic environmental change. We find that past expansion and divergence events coincided with a warming environment and the subsequent closure of the land bridge between Europe and the United Kingdom. We also find turnover in British roe deer haplotypes between the late-Holocene and modern day that have likely resulted from recent human disturbance activities such as habitat perturbation, overhunting and restocking.     

Anthropogenic and Climatic Effects on the Distribution of <Emphasis Type="Italic">Eulemur</Emphasis> Species: An Ecological Niche Modeling Approach

Several factors can influence primate distributions, including evolutionary history, interspecific competition, climate, and anthropogenic impacts. In Madagascar, several small spatial scale studies have shown that anthropogenic habitat modification affects the density and distribution of many lemur species. Ecological niche models can be used to examine broad-scale influences of anthropogenic impacts on primate distributions. In this study, we examine how climate and anthropogenic factors influence the distribution of 11 Eulemur species using ecological niche models. Specifically, we created one set of models only using rainfall and temperature variables. We then created a second set of models that combined these climate variables with three anthropogenic factors: distance to dense settlements, villages, and croplands. We used MaxEnt to generate all the models. We found that the addition of anthropogenic variables improved the climate models. Also, most Eulemur species exhibited reduced predicted geographic distributions once anthropogenic factors were added to the model. Distance to dense settlements was the most important anthropogenic factor in most cases. We suggest that including anthropogenic variables in ecological niche models is important for understanding primate distributions, especially in regions with significant human impacts. In addition, we identify several Eulemur species that were most affected by anthropogenic factors and should be the focus of increased conservation efforts.     

Differences in body mass, health status and genetic variation between insular and mainland brown hares (Lepus europaeus) in Sweden

Introduced populations can be affected by random processes such as genetic drift, deterministic processes given by the local environmental conditions and anthropogenic factors such as hunting and management. Geographically constrained populations are particularly exposed to these processes, and altogether, these factors may result in rapid differentiation from the ancestral populations. The introduced European brown hare (Lepus europaeus) population on the island Ven is isolated from the Swedish and Danish mainland. Undocumented observations suggest that the hares on the island have been increasingly diseased in recent years and also decreased in body size. To test the substance of these observations, as well as the potential for inbreeding depression in this geographically constrained population, a total of 321 hares from Ven and three reference populations on the Swedish mainland were analysed with respect to body mass, general health status and genetic variation. The results confirm that the hares on Ven have lower body mass than hares on the mainland, but there are no indications of health deficits. We argue that the difference in body mass primarily is an island effect of stress and/or nutritional shortage, possibly induced by high population density, anthropogenic selection regimes and absence of mammalian meso-predators. Further, the genetic data indicate that the insular population is substructured, and subadults from these two subpopulations differ in body mass. This apparent substructuring could be due to chance effects, but may also be related to assortative mating or presence of sustained populations with different ancestry.     

Efficacy of population size structure as a bioassessment tool in freshwaters

Bioassessments are used to measure system health and assess disturbance. While fish-based freshwater bioassessments are cost-effective and perform well in speciose systems, such bioassessments remain difficult to implement in species-poor Mediterranean regions. Population size structure metrics may provide meaningful biological information where depauperate communities preclude the richness and composition measures generally used. We focus our assessments of population size structure responses to anthropogenic perturbation on one of the most widespread native stream fish (Squalius laietanus). We explore a number of population size statistics as metrics for a Mediterranean region, where current bioassessments perform poorly. Our sampling encompassed 311 sites across Catalonia (NE Spain) where we characterized anthropogenic perturbation using a summary of impacts, including local data on stream condition and landscape indicators of degradation, via a principal component analysis. Anthropogenic perturbation in streams was collinear with altitudinal gradients and highlights the importance of appropriate statistical techniques. Of the population size structure metrics explored, average length was the most sensitive to anthropogenic perturbation and generally increased along the disturbance gradient. Although we expected to find consistent changes in variance, kurtosis, and skewness, the observed relationships were weak. River basin mediated responses suggest the importance of environmental landscape factors. The unexpected increases of mean S. laietanus body size with anthropogenic perturbation, strong effects of river basin, collinearity with spatial gradients and the species-specific nature of responses preclude the direct application of size structure in freshwater bioassessments. Although its application in fish-based freshwater bioassessments appears difficult, population size structure can provide insights in species-specific applications and management.     

Estimating the rate of increase for the finless porpoise with special attention to predictions for the Inland Sea population in Japan

The finless porpoise Neophocaena asiaeorientalis inhabits coastal waters and rivers in East Asia and is exposed to various human activities. This species is listed on the IUCN Red List of Threatened Species due to a reduction in abundance. Although human-induced mortality can be a threat to porpoise populations, future anthropogenic impacts have not been quantitatively evaluated due to lack of demographic information. Adequate future population projections are needed to form the basis for conservation measures before the population declines to critical levels. We conducted a population viability analysis for the population of finless porpoise in the Inland Sea, Japan using a Leslie matrix model composed of age-specific survival and fertility rates. We described the uncertainty in the annual rate of increase (λ) for the finless porpoise using randomly sampled estimates of survival rate for other cetaceans with similar life histories. Plausible median estimates of λ ranged from 1.041 (age at first reproduction [AFR] = 7) to 1.056 (AFR = 5). Future population changes and extinction probabilities were predicted after combining these estimates with a predicted human-induced mortality rate (M) and available abundance estimates. The extinction probability after 100 years was 0 %. However, the probability of the quasi-extinction (<100 individuals) was as high as 79.0 % after 100 years. The results also suggest that the persistence of the finless porpoise population could be achieved with a small effort to reduce anthropogenic mortality.     

Comparative analysis of external factors affecting the population of wild reindeer in Taimyr

This paper surveys external ecological factors that have an impact on the population of wild reindeer on the Taimyr Peninsula. These factors are estimated according to their influence on the abundance of the reindeer population. The key factors are examined with relation to bioenergetics. The population conservation strategy in view of the potential resumption of anthropogenic influence due to further industrial development of Taimyr is proposed.     

Informing conservation strategies with museum genomics: Long‐term effects of past anthropogenic persecution on the elusive European wildcat

Like many carnivore species, European wildcats (Felis silvestris) have suffered severe anthropogenic population declines in the past, resulting in a strong population bottleneck at the beginning of the 20th century. In Germany, the species has managed to survive its near extinction in small isolated areas and is currently recolonizing former habitats owing to legal protection and concerted conservation efforts. Here, we SNP‐genotyped and mtDNA‐sequenced 56 historical and 650 contemporary samples to assess the impact of massive persecution on genetic diversity, population structure, and hybridization dynamics of wildcats. Spatiotemporal analyses suggest that the presumed postglacial differentiation between two genetically distinct metapopulations in Germany is in fact the result of the anthropogenic bottleneck followed by re‐expansion from few secluded refugia. We found that, despite the bottleneck, populations experienced no severe genetic erosion, nor suffered from elevated inbreeding or showed signs of increased hybridization with domestic cats. Our findings have significant implications for current wildcat conservation strategies, as the data analyses show that the two presently recognized wildcat population clusters should be treated as a single conservation unit. Although current populations appear under no imminent threat from genetic factors, fostering connectivity through the implementation of forest corridors will facilitate the preservation of genetic diversity and promote long‐term viability. The present study documents how museum collections can be used as essential resource for assessing long‐term anthropogenic effects on natural populations, for example, regarding population structure and the delineation of appropriate conservation units, potentially informing todays'' species conservation.     

Modeling the effects of anthropogenic exploitation and climate change on an endemic stag beetle,Lucanus miwai (Lucanidae), of Taiwan

Loss of biodiversity is a worldwide phenomenon and conservation of endemic species is becoming a pressing issue. However, species differ in life history characteristics, causing the best strategy for conservation to vary among species. Lucanus miwai is an endemic stag beetle of Taiwan, but the natural history and the conservation status of L. miwai have not been fully studied. Lucanus miwai adults live in forest-edge grassland habitats and are experiencing threats from anthropogenic exploitation. Additionally, climate change may threaten its long-term survival because of its specific habitat preference. Results from this study clearly indicate the need for more studies on the natural history of L. miwai and demonstrate that contemporary intensity of anthropogenic exploitation can have a negative effect on population size of this species. Future habitat loss because of global climate change, in addition, can be another major factor leading to population decline. Moreover, increasing demands on L. miwai because of population decline may lead to population extinction. In addition to protecting adult males from being collected, conservation strategies should also focus on discovering habitats utilized by individuals from different life stages, investigating the connectivity between populations, and maintaining the long-term availability of suitable habitats for L. miwai.     

Anthropogenic causes of the western Steller sea lion Eumetopias jubatus population decline and their threat to recovery

• 1 The western Steller sea lion Eumetopias jubatus population has experienced a chronic decline since the 1960s. The causes are likely multifactorial and a combination of anthropogenic and natural factors. A draft revised recovery plan for the Steller sea lion has been published by the US National Marine Fisheries Service, listing both anthropogenic and natural factors that may have contributed to the observed decline or which may be a threat to the recovery of the western Steller sea lion population. The purpose of this review is to consider the anthropogenic threats to this stock.
• 2 Anthropogenic sources of mortality include fisheries competition resulting in nutritional stress, mortality incidental to commercial fisheries (i.e. fisheries by‐catch), subsistence hunts, legal and illegal shooting, commercial hunts, anthropogenic‐related contamination, and research‐induced mortalities.
• 3 We present evidence that the following anthropogenic factors likely contributed to the decline of the western Steller sea lion population over the last 40 years: (i) mortality incidental to commercial fisheries (i.e. by‐catch); (ii) commercial hunting of western Steller sea lions; and (iii) legal and illegal shooting; whereas the subsistence hunts for western Steller sea lions and mortality incidental to research were not likely to be contributors to the observed decline.
• 4 Further, we present evidence that the following can be excluded as significant anthropogenic threats to the recovery of the western Steller sea lion population: (i) mortality incidental to commercial fishing; (ii) legal and illegal shooting; (iii) commercial hunts of Steller sea lions; (iv) subsistence hunting; and (v) mortality incidental to research.
• 5 Competition with fisheries resulting in nutritional stress, and the potential impacts of contaminants, are two anthropogenic factors that should continue to be a priority for the various organizations currently doing research on this population.

     

Assessing the effects of sewage effluents in a Mediterranean creek: fish population features and biotic indices

Sewage effluents are one of the main anthropogenic stressors in Mediterranean rivers. The establishment of a cause?Ceffect relationship is hindered in natural systems by the existence of confounding factors (i.e. biotic interactions). Here we analysed the effects that anthropogenic stressors have on a mono-specific fish community (Iberian redfin barbel population, Barbus haasi) inhabiting the northern edge of its distribution range. In Spring 2004, a total of 40 consecutive sampling sites were surveyed in Vallvidrera creek, and 1,331 specimens were measured and weighed. A principal component analysis was performed to synthesize the information provided by 22 environmental variables. Analysis of variance, bivariate correlation analyses and multiple linear regressions were then used to determine the influence of the environmental gradients built (water quality, hydromorphology, woods and macrophytes, and degree of silting) on fish population features (fish size, body condition status, density and biomass). The findings revealed that water quality was the most significant environmental gradient for this fish population. In particular, fish density decreases and fish length increases in those sites exposed to sewage. Additionally, our results showed the best body condition of those specimens inhabiting fast flow reaches which confirms the rheophilous condition of B. haasi. However, these findings were unnoticed for the current version of the index of biotic integrity using fish as bioindicators in Catalonia. Resource managers need to refine diagnostic tools in order to detect subtle deleterious changes on fish communities before they become evident at population scale. Conservation measures should be focused in these small streams in where the best preserved native fish populations usually inhabit. This study suggests the need to change water management policies in Mediterranean rivers to improve the water quality of sewage effluents and increase the dilution power of these rivers.     

Developmental instability of the organism as a result of pessimization of environment under anthropogenic transformation of natural landscapes

The value of fluctuating asymmetry is considered to be an indicator of the developmental instability of the organism. The consequences of activities of the mining industry facilities, which are characterized by alienation and transformation of large areas of natural landscapes, are analyzed as an anthropogenic factor. The objects of study were small mammals (northern red-backed (Clethrionomys rutilus) and gray red-backed (Clethrionomys rufocanus) voles, tundra vole (Microtus oeconomus), Laxmann’s (Sorex caecutiens) and tundra (S. tundrensis) shrews) and trees (Japanese white birch (Betula platyphylla), Betula divaricate, Betula exilis, Duschekia fruticosa, and busket willow (Salix viminalis)). In total, 3500 skulls and approximately 30000 leaves collected in the taiga zone of Yakutia were studied. The index of fluctuating asymmetry, as well as population parameters and composition of small mammal communities, were analyzed. The data on the value of the fluctuating asymmetry in the studied species in natural habitats are given. It is shown that, in natural conditions, this parameter can rise with deterioration in living conditions, particularly at the ecological periphery of the range. Anthropogenic transformation of natural landscapes creates an “anthropogenic periphery” and causes changes similar to the adaptive responses at the northern limit of the distribution of species. It was found that, through pollution and disruption of ecosystems, the mining industry affects all levels of organization of the living matter, but the population and cenotic parameters give an unambiguous response only at macroanthropogenic transformations. Increase in the level of fluctuating asymmetry is the most sensitive indicator of anthropogenic impact and it should also be taken into account that disruptions in the developmental stability of an organism reflect the destructive processes occurring in the population and community.