Factors determining mammal species richness on habitat islands and isolates: habitat diversity, disturbance, species interactions and guild assembly rules

2000 ◽  
Vol 9 (1) ◽  
pp. 19-37 ◽  
Author(s):  
Barry J. Fox ◽  
Marilyn D. Fox
Author(s):  
Susan Glenn ◽  
Brian Chapman ◽  
Rebecca Rudman ◽  
Ian Butler

The equilibrium theory of island biogeography proposes that on an island of a given area, there exists an equilibrium number of species when the rates of immigration and local extinction of species are equal (MacArthur and Wilson 1967). This theory has been applied to park systems because parks may act as functional islands when surrounding unprotected land is cleared of natural vegetation. Alteration of these surrounding habitats isolates these parks and reduces the effective area, causing a decrease in the equilibrium number of species. In animal communities, this process is called faunal collapse (Soule et al. 1979).The effects of park isolation and faunal collapse have been studied for mammals in Rocky Mountain parks (Picton 1979, Newmark 1986, Glenn and Nudds 1989). In western U.S. parks, extinctions were more numerous in smaller or older parks (Newmark 1987). Area, topographic diversity, and habitat diversity have been correlated with mammal species richness in western North American parks (Picton 1979, Newmark 1986). Initial population size was also related to the extinction probability of a species (Newmark 1986). It has been proposed that all parks in a region are subject to similar factors influencing local extinctions, and therefore a similar suite of species should become locally extinct in all parks (Patterson and Atmar 1986, Patterson 1987). This means that a nested subset pattern is produced, where parks with low species richness contain mainly species already present in parks with high species richness. This pattern was not found for Canadian parks, where even small parks contained different species assemblages (Glenn 1990). The objectives of this three-year study are to: (i) identify mammal species that have become locally extinct in each of the Rocky Mountain National Parks; (ii) distinguish between hypotheses regarding the causes of these local extinctions in National Parks; (iii) determine if the same species become locally extinct in all parks; and (iv) identify potential sites for future protection of species prone to extinction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng Gong ◽  
Liangtao Li ◽  
Jan C. Axmarcher ◽  
Zhenrong Yu ◽  
Yunhui Liu

AbstractIn the intensively farmed, homogenous agricultural landscape of the North China Plain, family graveyards form distinct cultural landscape features. In addition to their cultural value, these graveyards represent semi-natural habitat islands whose potential roles in biodiversity conservation and ecological functioning has remained poorly understood. In this study, we investigated plant species richness on 199 family graveyards of different ages and sizes. In accordance with biogeography theory, both overall and insect-pollinated plant species richness increased with area and age of graveyards. Even small graveyards show a strong potential for conserving local plant richness, and a mosaic of both large and small family graveyards could play an important role in the conservation of farmland biodiversity and related ecosystem functions. The launch of agri-environmental measures that conserve and create semi-natural habitats, in turn benefitting agricultural biodiversity and ecological functioning, has proven difficult in China due to the shortage of dispensable arable land. Given the great value of family graveyards as semi-natural habitats reflected in our study, we propose to focus preliminary efforts on conserving these landscape features as existing, widespread and culturally important semi-natural habitat islands. This would represent an effective, complementary policy to a subsequent re-establishment of other semi-natural habitats for the conservation of biodiversity and ecological functioning in agricultural landscapes.


Author(s):  
Jiawei Feng ◽  
Yifei Sun ◽  
Hailong Li ◽  
Yuqi Xiao ◽  
Dandan Zhang ◽  
...  

2008 ◽  
Vol 59 (10) ◽  
pp. 940 ◽  
Author(s):  
Liesbet Boven ◽  
Bram Vanschoenwinkel ◽  
Els R. De Roeck ◽  
Ann Hulsmans ◽  
Luc Brendonck

Large branchiopods are threatened worldwide by the loss and degradation of their temporary aquatic habitats owing to drainage and intensive agriculture. Sound ecological knowledge of their diversity and distribution is a prerequisite to formulate effective conservation measures. In the present study, large branchiopods were collected from 82 temporary freshwater pools belonging to five habitat types in Kiskunság (Hungary). Dormant propagule bank analysis complemented the field survey. Eleven species were found, with large branchiopods occurring in more than half of the study systems. The high regional species richness and occurrence frequency of large branchiopods make Kiskunság a true ‘hot spot’ of large branchiopod diversity. The local environment was more important than spatial factors (isolation) in explaining the presence of the most common species. Dispersal was most likely not limiting for the large branchiopods in the study area and colonisation success of different species was differentially affected by local conditions, possibly invertebrate predation risk and hydroperiod. Meadow pools and wheel tracks contributed most to regional species richness through the presence of rare and exclusive species. To conserve branchiopod diversity, we stress the importance of high habitat diversity in the landscape and the need to conserve neglected habitats such as wheel tracks.


2016 ◽  
Vol 32 (6) ◽  
pp. 760-769 ◽  
Author(s):  
J. Tyler Faith ◽  
Joe Dortch ◽  
Chelsea Jones ◽  
James Shulmeister ◽  
Kenny J. Travouillon

2022 ◽  
Vol 220 ◽  
pp. 104337
Author(s):  
Aaron M. Grade ◽  
Paige S. Warren ◽  
Susannah B. Lerman

2012 ◽  
Vol 2012 ◽  
pp. 1-13
Author(s):  
Ana L. Márquez ◽  
Raimundo Real ◽  
Marta S. Kin ◽  
José Carlos Guerrero ◽  
Betina Galván ◽  
...  

We analysed the main geographical trends of terrestrial mammal species richness (SR) in Argentina, assessing how broad-scale environmental variation (defined by climatic and topographic variables) and the spatial form of the country (defined by spatial filters based on spatial eigenvector mapping (SEVM)) influence the kinds and the numbers of mammal species along these geographical trends. We also evaluated if there are pure geographical trends not accounted for by the environmental or spatial factors. The environmental variables and spatial filters that simultaneously correlated with the geographical variables and SR were considered potential causes of the geographic trends. We performed partial correlations between SR and the geographical variables, maintaining the selected explanatory variables statistically constant, to determine if SR was fully explained by them or if a significant residual geographic pattern remained. All groups and subgroups presented a latitudinal gradient not attributable to the spatial form of the country. Most of these trends were not explained by climate. We used a variation partitioning procedure to quantify the pure geographic trend (PGT) that remained unaccounted for. The PGT was larger for latitudinal than for longitudinal gradients. This suggests that historical or purely geographical causes may also be relevant drivers of these geographical gradients in mammal diversity.


Parasitology ◽  
1989 ◽  
Vol 98 (1) ◽  
pp. 145-150 ◽  
Author(s):  
S. S. J. Montgomery ◽  
W. I. Montgomery

SummaryMean species richness and diversity of the helminth infracommunity of Apodemus sylvaticus in woodland areas of Co. Down, Northern Ireland, varied in time and space. Variation in infracommunity structure among individual hosts, however, always accounted for more than 60% of the variation in the data from different places or different times. Helminth species richness increased with increasing population density, the percentage of the host population 16 weeks old or older, and the proportion of the host population with animal material in their stomachs, at two sites monitored over 33 months. The basis for spatial variation in infracommunity structure is less certain but host dynamics and differences in diet are likely to play some role. It is concluded that analysis at the infracommunity level focuses closely on the potential for species interactions and overlap in resource utilization. Infracommunity structure, at least in the case of A. sylvaticus, varies markedly in time and space and between individual hosts. Such variation should not be ignored in comparative studies.


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