Woodland reserves within an urban agglomeration as important refuges for small mammals

Abstract

The aim of the study was to determine the species richness (S, Chao- 1 index) and diversity (Shannon-Wiener H’ index, diversity profiles) of small mammal assemblages in woodland reserves in an urban agglomeration and to compare the similarity of assemblages (with the use of Ward’s method) in terms of proportions of small mammals connected to the habitats of different level of naturalness. The work was conducted from 2004-2015 at 9 woodland reserves in Warsaw (Poland). On the basis of the analysis of pellets of tawny owls Strix aluco, 2792 individuals were identified (24 species). Reserves supported from 7 to 16 of the small mammal species, the highest overall number of species estimated (Chao-1) was 19. Species present in every reserve were Apodemus flavicollis, A. agrarius, Rattus norvegicus, Sorex araneus and Talpa europaea. Least frequent were Microtus agrestis and M. subterraneus. Seven species of bats were detected. Species diversity was lower in the biggest forest complexes, where forest rodents dominated small mammal assemblage. The heterogeneity of habitats within reserve and in the surroundings, in combination with limited human-interference, resulted in an increase in the species diversity. Overall, the reserves under study were an important refuge for small mammals within the Warsaw agglomeration. However, safeguarding of adjacent areas against excessive anthropogenic change is needed and ecological corridors that link different areas need to be retained.

Pressures and Threats to Nature Related to Human Activities in European Urban and Suburban Forests

“…Poland [55,56,58,59], Slovenia [61], Turkey [49], Europe [6], Globally [62] HF Greater proportion of forest edge (reduction of the area of the forest interior, with a specific microclimate) Poland [58,59], Finland [37,60] 1 Directions of negative relations: HF-"humans to forests", HH-"humans to humans".…”

“…A necessary condition for the survival of animals is the presence of shelters in the forest [152], food, water, and tranquility, especially during breeding. Urban development and increasing traffic, as well as the intensification of the human use of urban and suburban forests, strongly affect wildlife (Table 3), causing decreases in animal diversity, distribution, and the composition of communities [56,124,[153][154][155][156]. Poland [53,59,151], Globally [160] HF Threats to animals from the garbage in forests (for example, as a trap) Poland [99] HF, HH…”

“…Germany [35], Poland [54,161] HF Scaring wild animal in their refuges (urban and suburban nature reserves, national parks) Poland [21,36,56,[162][163][164][165], Austria [166] HF, HH Frequent presence of dogs accompanying the visitors (especially unleashed dogs), which can scare and attack wild animals (high losses of animals recorded in winter when the snow cover is thick)…”

“…Similarly to the case of plants, habitat devastation is related to deforestation [63,170] and fragmentation [16,32,136] but also to urbanization close to/in the forest, the lack of foraging sites, and isolation, which is troublesome both for the movement and dispersal of individuals [16,32]. This is why wildlife corridors are necessary, especially in urban and suburban areas [3,50,56,61,179]. On the European Union scale, the protection of ecological corridors is planned in the Natura 2000 network; however, from the point of view of the needs of species associated with urban and suburban forests, this may be insufficient.…”

Management and Social Problems Linked to the Human Use of European Urban and Suburban Forests

“…Each forest has such a value for the society ( [19,20], e.g., in the United Kingdom [21], Finland [9,22,23], Austria [24,25], Switzerland [12], Poland (e.g., [4,7,[26][27][28]), Slovenia [29], Sweden [6,30], the Netherlands [31], and Norway [31]). Urban and suburban forests are often habitats of diverse (also rare and valuable) species of plants, fungi, and animals (e.g., [32][33][34][35]). The high environmental value of selected forests inspires some of the visitors or forest managers to undertake conceptual or/and practical measures aimed at their protection (e.g., [9,27,36,37]).…”