Distribution of arthropods in relation to forest patch size, edge, and stand characteristics

1998 ◽  
Vol 28 (7) ◽  
pp. 1068-1072 ◽  
Author(s):  
Jukka Jokimäki ◽  
Esa Huhta ◽  
Juhani Itämies ◽  
Pekka Rahko

We studied the abundance of arthropods in relation to forest patch size, edge orientation, distance from the forest - open-land edge, and stand characteristics in pine-dominated forests in northern Finland. Arthropod samples were collected using the sweep-net method. The total catch of arthropods, catches from the field layer and deciduous shrubs, the numbers of flying arthropods, small (<1 mm) arthropods, and the numbers of seven different arthropod taxa (viz. Linyphiidae (Arachnida), Cicadellidae (Homoptera), Diptera, Brachycera (Diptera), Nematocera (Diptera), and Hymenoptera and Ichneumonidae (Hymenoptera)) were lower in large forest patches (>5 ha) than in small patches (5 ha). The edge orientation and the type of adjacent open area (clearcut area or treeless mire) had no impact on the abundance of arthopods in the patches. The distance from the forest edge affected the total abundance of arthropods, small arthropods, flying arthropods, and Coleoptera (especially Cantharidae) in that all decreased in number from the forest edge to the interior of the forest stand. The abundance of many arthropod taxa correlated positively with the numbers of saplings, deciduous shrubs, and spruces. It was clear that the existence of these vegetation characteristics mainly explained the observed differences in the abundance of arthropods between forest patches of different sizes and also between forest edges and stand interiors.

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 338
Author(s):  
David Hladnik ◽  
Andrej Kobler ◽  
Janez Pirnat

In the presented research, we studied the forest edge structure of urban and peri-urban forests on the outskirts of Ljubljana (Slovenia) consisting of a number of patches covering the collective surface of 1884 ha. They differ from each other according to the degree of fragmentation and by the share of the interior forest area. On the basis of LiDAR data, we conducted an analysis of the edges of the persistent forest patches and estimated them with regard to the land use they bordered on. The horizontal estimation of forest edges and the changes of forest edges, in the last decades, were estimated using digital orthophoto images of cyclic aerial surveys of Slovenia, from 1975 to 2018. The data, provided by LiDAR, were used to obtain an accurate estimate of forest edges and the metrics of their vertical canopy structure. On the basis of the canopy height model (CHM), we determined the height classes, the heights of the tallest trees, and indices of canopy height diversity (CHD) as variables subjected to a k-means cluster analysis. To determine the forest edge and trees stability, their heights and diameters at breast height (DBH) were measured and their canopy length and h/d (height/diameter) dimension ratios were estimated. In the study area of the Golovec forest patch, more than half of the forest edge segments (56%) border on residential buildings. After the construction of buildings, 54% of the newly formed forest edges developed a high and steep structure. Unfavorable h/d dimension ratio was estimated for 16% of trees, more among the coniferous than among the deciduous trees. Similar characteristics of newly formed forest edges bordering on built-up areas were determined in other sub-urban forest patches, despite the smaller share of such forest edges (19% and 10%, respectively). Tools and methods presented in the research enable the implementation of concrete silvicultural practices in a realistic time period and extend to ensure that adequate forestry measures are taken to minimize possible disturbances.


2014 ◽  
Vol 30 (6) ◽  
pp. 579-590 ◽  
Author(s):  
Dharmalingam Mohandass ◽  
Alice C. Hughes ◽  
Mason Campbell ◽  
Priya Davidar

Abstract:We investigate the effect of patch size on liana diversity and distribution in 19 patches of montane evergreen forest in the Nilgiri hills, Western Ghats, southern India. Additionally, we examined how liana species richness and community assemblage in both edge (within 10 m of the forest edge) and interior regions of forest patches respond to patch size, in order to infer the impact of forest expansion or reduction on the liana communities. A total of 1276 woody liana individuals of 15 species were identified, belonging to 10 genera and nine families. Total species richness of lianas was significantly positively related to forest-patch area, both when analysed for the entire patch, in addition to both core and edge regions when examined separately. Species richness of larger lianas also showed a significant positive relationship with increasing forest patch area. Community assemblage varied with respect to forest edge, with shade-dependent species only occurring in interior patch regions, shade-averse species in edge regions, and shade-tolerant species occurring throughout. Disturbance also played a role in determining the response of liana diversity to patch size, with heavily disturbed patches showing no relationship between patch size and diversity, whereas positive relationships exist in low to moderately disturbed patches. The most significant result is the change in liana community composition between small and larger fragments. Many species present in smaller patches are also present in edge zones of larger fragments. This suggests that lianas are important structural components of montane forest ecosystems, and their compositional patterns are possibly driven by succession. Moreover, this study reveals the importance of edge effect and patch size in influencing liana species richness and compositional patterns.


2008 ◽  
Vol 141 (10) ◽  
pp. 2585-2596 ◽  
Author(s):  
Eva Gaublomme ◽  
Frederik Hendrickx ◽  
Hilde Dhuyvetter ◽  
Konjev Desender

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 595-600 ◽  
Author(s):  
D. Ryan Norris ◽  
Bridget J. M. Stutchbury ◽  
Trevor E. Pitcher

Abstract We tested whether Hooded Warblers (Wilsonia citrina) avoided abrupt forest edges by radiotracking males breeding in small, isolated forest patches (0.5–2.0 ha) in northwest Pennsylvania. Because territory edges were synonymous with abrupt forest edges in all cases, we compared space use patterns with males radiotracked in a nearby continuous forest (150 ha), where we defined edge from territorial boundaries. Based on the proportion of edge to core area, males in both habitats avoided the area within 20 m of the edge, implying that males responded to the presence of territory edge rather than forest edge. Surprisingly, however, males in isolated fragments used the edge area significantly more than males in continuous forest, even when measured against the relative amount of edge area within each territory. Elevated levels of edge use were not related to distance of nests to edges, nest stage, or time of day. We conclude that the presence of physical edges is not the sole determinant of territorial space use in this species and there are likely additional social factors influencing occupancy rates in small, isolated woodlots. Therefore, definitions of forest-interior species based on edge use need to be reconsidered.


Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1264
Author(s):  
Jinki Kim ◽  
Duk-Byeong Park ◽  
Jung Il Seo

There is abundant evidence that green space in urban neighborhood is associated with physical activity and it is well known that physical activity contributes to human health. Physical activity fosters normal growth and development, can reduce the risk of chronic diseases, and can make people feel better and function better. Evidences also show that exposure to natural places can lead to positive mental health outcomes, whether a view of nature from a window, being within natural places, or exercising in these environments. The study aims to identify the factors of forest structure and socioeconomic characteristics influencing adults’ physical activity and health. A sample of 148,754 respondents from the Korea Community Health Survey, conducted in 2016, was analyzed. Measures included frequency of physical activity, stress, depression, and landscape metrics of forest patch. Hierarchical multiple regression analysis, controlling for socio-demographic characteristics, revealed that larger forest patches and the more irregular shapes were associated with more physical activity. The study also showed that the shape of forest patch and slope were associated with less mental health complaints, whereas composition related landscape metrics were not.


2017 ◽  
Vol 83 ◽  
pp. 1-14 ◽  
Author(s):  
Dharmalingam Mohandass ◽  
Mason J. Campbell ◽  
Alice C. Hughes ◽  
Christos Mammides ◽  
Priya Davidar

1999 ◽  
Vol 77 (8) ◽  
pp. 1288-1299 ◽  
Author(s):  
Mary B Kolozsvary ◽  
Robert K Swihart

We studied the effects of agriculturally induced fragmentation of forests and wetlands on amphibian assemblages and their distribution in a landscape of the midwestern United States. Potential breeding pools and upland areas in 30 forest patches of various sizes and degrees of isolation were intensively sampled for amphibians during April through August 1996 and March through August 1997 in Indiana. Species presence was documented using pitfall traps, anuran vocalization surveys, and cover-board sampling for adults and minnow traps and dip nets for larvae. Amphibian, anuran, and salamander assemblages were nonrandomly distributed across the landscape. American toads (Bufo americanus) and gray treefrogs (Hyla versicolor) were ubiquitous, whereas the distributions of several other species were ordered in a predictable manner. Logistic regression was used to develop predictive models of probabilities of occurrence for species in response to forest and wetland patch and landscape variables. Occurrence of redback salamanders (Plethodon cinereus) was positively associated with the area of a forest patch. Occurrence of ranid frogs was positively associated with proximity of wetlands for three of four species, and occurrences of smallmouth salamanders (Ambystoma texanum), spring peepers (Pseudacris crucifer), and western chorus frogs (Pseudacris triseriata) were related to the degree of wetland permanency. Multiple linear regression revealed that species richness was greatest for wetlands with intermediate degrees of permanency. The observed nonrandom distribution exhibited by several amphibians suggests that they respond to landscape-level attributes. Moreover, species differed substantially in the nature of their responses to fragmentation, consistent with differences in their life history and ecology.


2020 ◽  
Vol 66 (6) ◽  
Author(s):  
Sarah A. Mueller ◽  
Tobias E. Reiners ◽  
Katharina Steyer ◽  
Alina von Thaden ◽  
Annika Tiesmeyer ◽  
...  

AbstractFollowing severe population decline and local extinction due to massive habitat destruction and persecution, wildcats have recently reappeared in several parts of Germany’s low mountain region. It remains unknown how this reemergence occurred, specifically if local populations have been overlooked at low densities or if the species has successfully spread across the highly fragmented anthropogenic landscape. In the central German Rhön Mountains, for instance, wildcats were believed to be extinct during most of the twentieth century, however, the species was recently detected and subsequent genetic monitoring found the presence of a sizeable population. In this study, we used microsatellite and SNP genotypes from 146 wildcat individuals from 2008 to 2017 across a ~ 15,000 km2 area in the central German low mountain region to understand the population re-establishment of wildcats in the region. Bayesian clustering and subsequent analyses revealed that animals in the Rhön Mountains appear to be a mix from the two adjacent populations in the North and South of the area, suggesting a recent range expansion from two different directions. Both populations meet in the Rhön Biosphere Reserve, leading to an admixture of the northern, autochthonous, and the southern reintroduced wildcat population. While we cannot completely exclude the possibility of undetected population persistence, the high genetic homogeneity in the central German wildcat population and the lack of any signatures of past population decline in the Rhön favor a scenario of natural expansion. Our findings thus suggest that wildcats are well capable of rapid range expansion across richly structured landscape mosaics consisting of open land, settlements, and forest patches and document the potential of massive non-invasive genetic sampling when aiming to reconstruct the complex population and range dynamics of wildlife.


2002 ◽  
Vol 8 (2) ◽  
pp. 82 ◽  
Author(s):  
Michael A. MacDonald ◽  
Robert J. Taylor ◽  
Steven G. Candy

In Tasmania, a system of 100 m wide strips of native forest, referred to as wildlife habitat strips, is retained within production forest, including plantations. Thirty-nine points in 18 wildlife habitat strips within both eucalypt and pine plantations (which were not differentiated for the purposes of the present study) were paired with points in nearby extensive native forest and surveyed for birds. At non-riparian sites (upper slopes and ridges), bird species richness and total abundance were both significantly lower in habitat strips than in controls. This difference is quantitative rather than qualitative, as ordination did not distinguish strip sites and controls, and no species were obviously absent from habitat strips. Riparian zones showed no significant difference in species richness and total abundance between habitat strips and controls. Species richness and total abundance relative to controls increased as wildlife habitat strip length increased over the measured range (0.4-2.1 km). It is thought that this may be because birds perceive strips as linear forest patches rather than corridors, so that there may be a habitat area effect. Other strip characteristics such as width and plantation age were not significant in riparian areas, but may be important on upper slopes and ridges, and the former will affect strip area. Wildlife habitat strips appear to be a valuable component of a conservation programme for birds in production forests in Tasmania.


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