Habitat fragmentation and the distribution of amphibians: patch and landscape correlates in farmland

1999 ◽  
Vol 77 (8) ◽  
pp. 1288-1299 ◽  
Author(s):  
Mary B Kolozsvary ◽  
Robert K Swihart
Keyword(s):  
Plethodon Cinereus ◽  
Hyla Versicolor ◽  
Pitfall Traps ◽  
Bufo Americanus ◽  
Forest Patches ◽  
Forest Patch ◽  
Pseudacris Crucifer ◽  
Chorus Frogs ◽  
Nonrandom Distribution ◽  
Landscape Level

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.

Predation on Hyla versicolor and Pseudacris crucifer during Reproduction

1990 ◽  
Vol 24 (2) ◽  
pp. 196 ◽  
Author(s):  
Steven H. Hinshaw ◽  
Brian K. Sullivan
Keyword(s):  
Hyla Versicolor ◽  
Pseudacris Crucifer

scholarly journals Exploring the Relationship between Forest Structure and Health

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1264
Author(s):  
Jinki Kim ◽  
Duk-Byeong Park ◽  
Jung Il Seo
Keyword(s):  
Mental Health ◽  
Physical Activity ◽  
Landscape Metrics ◽  
Forest Structure ◽  
Normal Growth ◽  
Urban Neighborhood ◽  
Forest Patches ◽  
Forest Patch ◽  
Irregular Shapes ◽  
And Function

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.

scholarly journals Adaptive Framework for the Delineation of Homogeneous Forest Areas Based on LiDAR Points

2019 ◽  
Vol 11 (2) ◽  
pp. 189 ◽  
Author(s):  
Moritz Bruggisser ◽  
Markus Hollaus ◽  
Di Wang ◽  
Norbert Pfeifer
Keyword(s):  
Laser Scanning ◽  
Water Cycle ◽  
Canopy Structure ◽  
Point Clouds ◽  
Forest Patches ◽  
Forest Patch ◽  
Flexible Framework ◽  
Foliage Density ◽  
The One ◽  
Forest Conditions

We propose a flexible framework for automated forest patch delineations that exploits a set of canopy structure features computed from airborne laser scanning (ALS) point clouds. The approach is based on an iterative subdivision of the point cloud using k-means clustering followed by an iterative merging step to tackle oversegmentation. The framework can be adapted for different applications by selecting relevant input features that best measure the intended homogeneity. In our study, the performance of the segmentation framework was tested for the delineation of forest patches with a homogeneous canopy height structure on the one hand and with similar water cycle conditions on the other. For the latter delineation, canopy components that impact interception and evapotranspiration were used, and the delineation was mainly driven by leaf area, tree functional type, and foliage density. The framework was further tested on two scenes covering a variety of forest conditions and topographies. We demonstrate that the delineated patches capture well the spatial distributions of relevant canopy features that are used for defining the homogeneity. The consistencies range from R 2 = 0 . 84 to R 2 = 0 . 86 and from R 2 = 0 . 80 to R 2 = 0 . 91 for the most relevant features in the delineation of patches with similar height structure and water cycle conditions, respectively.

The biology of Trypanosoma andersoni n. sp. and Trypanosoma grylli Nigrelli, 1944 (Kinetoplastida) from Hyla versicolor LeConte, 1825 (Anura)

1982 ◽  
Vol 60 (2) ◽  
pp. 116-123 ◽  
Author(s):  
Brian O. Reilly ◽  
P. T. K. Woo
Keyword(s):  
Rana Pipiens ◽  
Rana Catesbeiana ◽  
Rana Sylvatica ◽  
Hyla Versicolor ◽  
Bufo Americanus ◽  
Hyla Cinerea ◽  
Southern Ontario ◽  
Osteopilus Septentrionalis ◽  
Centrifugation Technique ◽  
Acris Gryllus

From May 1979 to July 1980, the blood of 196 mature Hyla versicolor LeConte from six sites in southern Ontario and southeastern Manitoba was examined for trypanosomes using the haematocrit centrifugation technique. Trypanosoma andersoni n. sp. and Trypanosoma grylli Nigrelli were found in 5.2 and 5.6% of the frogs examined. Three frogs (1.5%) were infected with both species of trypanosomes. Blood trypomastigotes of both species were monomorphic. Blood trypomastigotes of T. andersoni n. sp. were long and slender, tapering at both ends, whereas those of T. grylli were pyriform with a rounded posterior and tapered anterior.Both blood and culture forms of these trypanosomes were infective to laboratory-raised H. versicolor and Hyla crucifer Wied. Trypanosoma grylli was also infective to a field-collected Acris gryllus (LeConte). Neither trypanosome was infective to laboratory-raised Rana catesbeiana Shaw, Rana clamitans Rafinesque tadpoles, Rana pipiens Schreber, Rana sylvatica LeConte, or Xenopus laevis Daudin. Trypanosoma andersoni n. sp. was also not infective to laboratory-raised Bufo americanus Holbrook, Pseudacris triseriata (Wied), or to field-collected Hyla cinerea (Schneider) and Osteopilus septentrionalis Dumeril and Bibron. Neither species was infective to field-collected Notophthalmus viridescens (Rafinesque).

scholarly journals Recovery within a population of the Critically Endangered citron-crested cockatoo Cacatua sulphurea citrinocristata in Indonesia after 10 years of international trade control

Oryx ◽  
2006 ◽  
Vol 40 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Alexis J. Cahill ◽  
Jonathan S. Walker ◽  
Stuart J. Marsden
Keyword(s):  
International Trade ◽  
Forest Cover ◽  
Population Data ◽  
Small Population ◽  
Forest Patches ◽  
Field Methods ◽  
Forest Patch ◽  
Forest Sites ◽  
Before And After ◽  
Trade Control

Moratoria on international trade are frequently used to protect threatened species but few studies have examined their effectiveness in allowing populations to recover. We present population data collected before and after a moratorium on trade in the citron-crested cockatoo Cacatua sulphurea citrinocristata, a distinctive subspecies of the yellow-crested cockatoo endemic to Sumba, Indonesia. Before legal trade ceased in 1993 numbers of cockatoos leaving Sumba averaged c. 1,600 per year, and the 1992 population, estimated at 3,200, surely could not sustain such a level of trade. We surveyed cockatoos in four forest patches on Sumba in 1992, and then surveyed these same forest patches 10 years later, using the same field methods. Forest cover within the four patches was similar between years. We recorded a statistically significant increase in overall cockatoo density, from c. 2 birds per km2 in 1992 to >4 per km2 in 2002. Group sizes were also larger in 2002 than in 1992. Densities at two forest sites had increased considerably, at another the population was stable, but at one small forest patch a small population in 1992 had probably decreased. While the population has made a modest recovery, densities remain low compared to cockatoo populations elsewhere. Illegal trade is known to persist and its volume should be monitored closely.

scholarly journals Domestic dogs in a fragmented landscape in the Brazilian Atlantic Forest: abundance, habitat use and caring by owners

2010 ◽  
Vol 70 (4) ◽  
pp. 987-994 ◽  
Author(s):  
PC. Torres ◽  
PI. Prado
Keyword(s):  
Atlantic Forest ◽  
Domestic Dogs ◽  
Domestic Dog ◽  
Fragmented Landscape ◽  
Brazilian Atlantic Forest ◽  
Forest Patches ◽  
Forest Patch ◽  
Questionnaire Surveys ◽  
Responsible Ownership ◽  
Patch Edge

This study aimed at estimating the population size and attitudes of residents towards caring for domestic dogs, through questionnaire surveys, as well as the frequency of these animals in different habitats (anthropic and forest patch), using scent stations. The study was conducted in a severely fragmented area of the Brazilian Atlantic Forest. A large number of unrestricted dogs was recorded, averaging 6.2 ind/km². These dogs have owners and are regularly fed. Dog records decreased from the anthropogenic matrix to the forest patch edge, which suggests that dogs act as an edge effect on forest patches. Encounters between domestic dog and wild animals can still be frequent in severely fragmented landscapes, mainly at the forest edges. However the fact that most dogs have an owner and are more frequent in the anthropic habitat suggests that their putative effects are less severe than expected for a carnivore of such abundance, but the reinforcement of responsible ownership is needed to further ameliorate such effects.

Does physical or acoustical disturbance cause male pickerel frogs, Rana palustris, to vocalize underwater?

2008 ◽  
Vol 29 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Mac Given
Keyword(s):  
Test Period ◽  
Advertisement Call ◽  
Vocal Repertoire ◽  
Bufo Americanus ◽  
Physical Disturbance ◽  
Pseudacris Crucifer ◽  
Aggressive Calls

Abstract Male pickerel frogs (Rana palustris) vocalize both above water and underwater. Males have a complex vocal repertoire consisting of an advertisement call and two additional call types (i.e., aggressive calls) that can be elicited by the playback of a conspecific advertisement call. Additionally, in a previous study, males in these playbacks often dove and vocalized underwater for a few minutes before returning to the surface. The purpose of this study was to investigate whether physical or acoustical disturbance cause male pickerel frogs to call underwater. Experimental manipulations were performed with resident males that, initially, were calling above water. In the first, 16 males were physically disturbed with the intent to make them dive underwater. Eleven of these began to call underwater within 10 to 95 seconds and continued for up to four minutes before returning to calling above water. The second experiment involved playbacks in which males were disturbed acoustically by two minutes of continuous advertisement calling from either one Bufo americanus or Pseudacris crucifer male. Only one of 15 males dove and then called underwater in response to B. americanus calls even though most subjects emitted aggressive calls during the test period, and no male called underwater in response to P. crucifer calls (n = 13). In conclusion, male pickerel frogs will shift to underwater calling in response to a physical disturbance, but do not shift in response to the sounds of one heterospecific caller.

scholarly journals Gamebird responses to anthropogenic forest fragmentation and degradation in a southern Amazonian landscape

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3442 ◽  
Author(s):  
Fernanda Michalski ◽  
Carlos A. Peres
Keyword(s):  
Forest Fragmentation ◽  
Census Data ◽  
Forest Disturbance ◽  
Selective Logging ◽  
Forest Birds ◽  
Line Transect ◽  
Forest Patches ◽  
Forest Patch ◽  
Species Persistence ◽  
Gamebird Species

Although large-bodied tropical forest birds are impacted by both habitat loss and fragmentation, their patterns of habitat occupancy will also depend on the degree of forest habitat disturbance, which may interact synergistically or additively with fragmentation effects. Here, we examine the effects of forest patch and landscape metrics, and levels of forest disturbance on the patterns of persistence of six gamebird taxa in the southern Brazilian Amazon. We use both interview data conducted with long-term residents and/or landowners from 129 remnant forest patches and 15 continuous forest sites and line-transect census data from a subset of 21 forest patches and two continuous forests. Forest patch area was the strongest predictor of species persistence, explaining as much as 46% of the overall variation in gamebird species richness. Logistic regression models showed that anthropogenic disturbance—including surface wildfires, selective logging and hunting pressure—had a variety of effects on species persistence. Most large-bodied gamebird species were sensitive to forest fragmentation, occupying primarily large, high-quality forest patches in higher abundances, and were typically absent from patches <100 ha. Our findings highlight the importance of large (>10,000 ha), relatively undisturbed forest patches to both maximize persistence and maintain baseline abundances of large neotropical forest birds.

scholarly journals CHORUSING PATTERNS OF A DIVERSE ANURAN COMMUNITY, WITH AN EMPHASIS ON SOUTHERN CRAWFISH FROGS (LITHOBATES AREOLATUS AREOLATUS)

2016 ◽  
pp. 1-10
Author(s):  
Donald T. McKnight ◽  
Day B. Ligon
Keyword(s):  
Life History ◽  
Critical Role ◽  
Hyla Versicolor ◽  
Hyla Cinerea ◽  
Life History Data ◽  
Chorus Frogs ◽  
Lithobates Areolatus ◽  
Calling Patterns ◽  
Gastrophryne Carolinensis ◽  
Green Treefrogs

Wildlife surveys have a critical role in conservation efforts and the collection of life history data. For anuran amphibians these surveys often focus on calling males. In order to further our understanding of anuran ecology, we used automated recording systems to monitor the calling activities of the anuran communities at two beaver-formed lakes and one cattle pond in southeastern Oklahoma. We documented 14 anuran species between 5 February and 28 April 2012. Temperature had a significant effect on the calling patterns of Eastern Narrow-mouthed Toads (Gastrophryne carolinensis), Green Treefrogs (Hyla cinerea), Gray Treefrogs (Hyla versicolor), Southern Crawfish Frogs (Lithobates areolatus areolatus), and Cajun Chorus Frogs (Pseudacris fouquettei). Temperature did not have a significant effect on the calling patterns of Dwarf American Toads (Anaxyrus americanus charlesmithi), American Bullfrogs (Lithobates catesbeianus), or Green Frogs (Lithobates clamitans). There was not a significant relationship between rainfall and calling for L. a. areolatus. The presence of several of these species, including L. a. areolatus and Hurter’s Spadefoots (Scaphiopus hurterii) was unusual because these anurans typically breed in ephemeral, fishless pools, but the beaver lakes are permanent and sustain populations of carnivorous fishes.

scholarly journals Spaceborne potential for examining taiga–tundra ecotone form and vulnerability

2016 ◽  
Vol 13 (13) ◽  
pp. 3847-3861 ◽  
Author(s):  
Paul M. Montesano ◽  
Guoqing Sun ◽  
Ralph O. Dubayah ◽  
K. Jon Ranson
Keyword(s):  
Forest Structure ◽  
Vegetation Change ◽  
Structural Changes ◽  
Vertical Component ◽  
Tree Cover ◽  
Maximum Height ◽  
Forest Patches ◽  
Forest Patch ◽  
Forest Height ◽  
Patch Scale

Abstract. In the taiga–tundra ecotone (TTE), site-dependent forest structure characteristics can influence the subtle and heterogeneous structural changes that occur across the broad circumpolar extent. Such changes may be related to ecotone form, described by the horizontal and vertical patterns of forest structure (e.g., tree cover, density, and height) within TTE forest patches, driven by local site conditions, and linked to ecotone dynamics. The unique circumstance of subtle, variable, and widespread vegetation change warrants the application of spaceborne data including high-resolution (< 5 m) spaceborne imagery (HRSI) across broad scales for examining TTE form and predicting dynamics. This study analyzes forest structure at the patch scale in the TTE to provide a means to examine both vertical and horizontal components of ecotone form. We demonstrate the potential of spaceborne data for integrating forest height and density to assess TTE form at the scale of forest patches across the circumpolar biome by (1) mapping forest patches in study sites along the TTE in northern Siberia with a multi-resolution suite of spaceborne data and (2) examining the uncertainty of forest patch height from this suite of data across sites of primarily diffuse TTE forms. Results demonstrate the opportunities for improving patch-scale spaceborne estimates of forest height, the vertical component of TTE form, with HRSI. The distribution of relative maximum height uncertainty based on prediction intervals is centered at  ∼  40 %, constraining the use of height for discerning differences in forest patches. We discuss this uncertainty in light of a conceptual model of general ecotone forms and highlight how the uncertainty of spaceborne estimates of height can contribute to the uncertainty in identifying TTE forms. A focus on reducing the uncertainty of height estimates in forest patches may improve depiction of TTE form, which may help explain variable forest responses in the TTE to climate change and the vulnerability of portions of the TTE to forest structure change.

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