Species richness and parasitism in a fragmented landscape: experiments and field studies with insects on Vicia sepium

Oecologia ◽  
2000 ◽  
Vol 122 (1) ◽  
pp. 129-137 ◽  
Author(s):  
A. Kruess ◽  
T. Tscharntke
Keyword(s):  
Species Richness ◽  
Field Studies ◽  
Fragmented Landscape

The butterfly fauna of the Griffith district, a fragmented semi-arid landscape in inland southern New South Wales

2006 ◽  
Vol 12 (2) ◽  
pp. 140 ◽  
Author(s):  
Michael F. Braby ◽  
Ted D. Edwards
Keyword(s):  
Species Richness ◽  
Arid Zone ◽  
New South ◽  
New South Wales ◽  
Summer Rainfall ◽  
Wagga Wagga ◽  
Fragmented Landscape ◽  
South Wales ◽  
Butterfly Fauna ◽  
Semi Arid

Thirty-three species of butterflies are recorded from the Griffith district in the semi-arid zone of inland southern New South Wales. The butterfly community comprises the following structure: 19 species (58%) are resident; 7 (21 %) are regular immigrants; 2 (6%) are irregular immigrants; 5 (15%) are vagrants. Except for a few migratory species, most occur in relatively low abundance. Lack of similar studies elsewhere in western New South Wales precludes generalizations regarding the species richness, composition and structure of semi-arid butterfly communities. Comparison of the butterfly fauna with that from five other inland regions on the slopes and foothills of the Great Diving Range, revealed that the Griffith district is most similar in species richness and composition to that of Deniliquin and to a lesser extent Wagga Wagga and Cowra in the south, than with two regions in the higher summer rainfall area of the north of the State (Coonabarabran-Mendooran, Narrabri-Bellata). Overall, the butterfly fauna of inland New South Wales (total of 73 species, of which 49 occur in the southern regions) is depauperate compared with that recorded from the coastal/subcoastal areas east of the Great Dividing Range. Attention is drawn to the conservation significance of several vegetation types and habitat remnants in the Griffith district. Much of the native vegetation in the district has been extensively modified since European settlement due to excessive clearing for agriculture, resulting in a highly fragmented landscape for the conservation of native flora and fauna. With the exception of the lycaenid Candalides hyacinthinus Simplex, which is considered threatened locally, there is a general absence of narrow range endemic butterflies associated with mallee-heathland or mallee-woodland, possibly as a result of widespread land clearing practices of mallee vegetation in the past.

Extrapolations from field studies and known faunas converge on dramatically increased estimates of global microgastrine parasitoid wasp species richness (Hymenoptera: Braconidae)

2012 ◽  
Vol 6 (4) ◽  
pp. 530-536 ◽  
Author(s):  
Josephine J. Rodriguez ◽  
Jose L. Fernández-Triana ◽  
M. Alex Smith ◽  
Daniel H. Janzen ◽  
Winnie Hallwachs ◽  
...  
Keyword(s):  
Species Richness ◽  
Parasitoid Wasp ◽  
Field Studies ◽  
Wasp Species

Partitioning the role of climate, pollution and old-growth woodland in the composition and richness of lichen epiphytes in Scotland

2010 ◽  
Vol 42 (5) ◽  
pp. 601-614 ◽  
Author(s):  
Christopher J. ELLIS ◽  
Brian J. COPPINS
Keyword(s):  
Species Richness ◽  
Regional Scale ◽  
Environmental Data ◽  
Fragmented Landscape ◽  
Least Squares Regression ◽  
Old Growth ◽  
Explanatory Variables ◽  
Species Response ◽  
The Difference

AbstractThis paper presents a study to partition the role of three regional-scale drivers – woodland extent and continuity, pollution regime, and climatic setting – in explaining the composition and richness of lichen epiphytes in Scotland. To do this we used partial canonical correspondence analysis and multiple least squares regression, to examine lichen communities across 170 study sites. First, our results demonstrate the importance of climate in explaining species composition. This highlights the relatively clean-air environment of Scotland within a European setting, and emphasizes the important consideration of regional context in the development of bioclimatic species-response models. This result contrasts with a previous similar study which collapsed complex environmental data into summary gradients, and which therefore discounted climate as a key factor. Second, we show a functional decoupling between composition and species richness, which was optimally explained by old-growth woodland extent and pollution, and only weakly explained by climate. The difference in explanatory variables between composition and richness is a focal issue in determining the processes by which species compositional change, driven by rapid and deep climate change, may indirectly impact species richness. For example, this impact may occur through an imbalance in rates of species extinction (for sensitive range-edge species) and establishment in a fragmented landscape (for dispersal-limited colonists), though operating against the ‘stabilizing effect’ of microclimatic setting.

scholarly journals Rapid survey of bats (Chiroptera) in the Atlantic Forest in eastern Sergipe, Brazil: unexpected diversity in a fragmented landscape

2020 ◽  
Vol 15 (3) ◽  
pp. 317-332
Author(s):  
Mônica A. Pedroso ◽  
Arivania S. Pereira ◽  
Helon S. Oliveira ◽  
J. Weverton S. Souza ◽  
Francis L.S. Caldas ◽  
...  
Keyword(s):  
Species Richness ◽  
Atlantic Forest ◽  
Northeastern Brazil ◽  
Fragmented Landscape ◽  
Forest Reserve ◽  
Alternative Strategies ◽  
Active Search ◽  
First Time

Despite advances in recent decades, the Atlantic Forest of northeastern Brazil is still one of the least studied regions of the country, regarding, for instance, the bat fauna. The present study reports on the results of a rapid survey of the bat fauna of a fragmented landscape in the Atlantic Forest of eastern Sergipe, in the legal forest reserve of Fazenda Santana, a commercial sugarcane plantation located in the adjoining municipalities of Japoatã and Pacatuba. We recorded 272 bats belonging to 23 species and four families, from which 265 individuals from 18 species from two families (Phyllostomidae and Vespertilionidae) were captured in the mist-nets, and seven individuals of six species from four families (Emballonuridae, Molossidae, Phyllostomidae and Vespertilionidae) were recorded during the active searches. This species richness was higher than that found in previous studies in the Atlantic Forest of northeastern Brazil. Lasiurus blossevillii and Micronycteris minuta were recorded in Sergipe for the first time, increasing to 57 the number of bat species known to occur in this state. The use of alternative strategies (such as active search and sampling one night per point, seeking to areas with greater availability of resources) in rapid surveys may contribute to the compilation of a more robust sampling, reinforcing the usefulness of this approach for the inventory of the bat fauna of a given region.

scholarly journals Correlates of hornbill distribution and abundance in rainforest fragments in the southern Western Ghats, India

2003 ◽  
Vol 13 (3) ◽  
pp. 199-212 ◽  
Author(s):  
T.R. Shankar Raman ◽  
Divya Mudappa
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Western Ghats ◽  
Fragmented Landscape ◽  
Coffee Plantations ◽  
Point Count ◽  
Point Counts ◽  
Tree Species Richness ◽  
Southern Western Ghats ◽  
Line Transects

The distribution and abundance patterns of Malabar Grey Hornbill Ocyceros griseus and Great Hornbill Buceros bicornis were studied in one undisturbed and one heavily altered rainforest landscape in the southern Western Ghats, India. The Agasthyamalai hills (Kalakad-Mundanthurai Tiger Reserve, KMTR) contained over 400 km2 of continuous rainforest, whereas the Anamalai hills (now Indira Gandhi Wildlife Sanctuary, IGWS) contained fragments of rainforest in a matrix of tea and coffee plantations. A comparison of point-count and line transect census techniques for Malabar Grey Hornbill at one site indicated much higher density estimates in point-counts (118.4/km2) than in line transects (51.5/km2), probably due to cumulative count over time in the former technique. Although line transects appeared more suitable for long-term monitoring of hornbill populations, point-counts may be useful for large-scale surveys, especially where forests are fragmented and terrain is unsuitable for line transects. A standard fixed radius point-count method was used to sample different altitude zones (600–1,500 m) in the undisturbed site (342 point-counts) and fragments ranging in size from 0.5 to 2,500 ha in the Anamalais (389 point-counts). In the fragmented landscape, Malabar Grey Hornbill was found in higher altitudes than in KMTR, extending to nearly all the disturbed fragments at mid-elevations (1,000–1,200 m). Great Hornbill persisted in the fragmented landscape using all three large fragments (> 200 ha). It was also recorded in four of five medium-sized fragments (25–200 ha) and one of five small fragments (< 25 ha), which was adjacent to shade coffee plantations. Abundance of Malabar Grey Hornbill declined with altitude and increased with food-tree species richness. Great Hornbill abundance increased with food-tree species richness, suggesting that maintenance of high diversity of hornbill food species in fragments is important for their persistence. It is likely that the smaller and less specialized Malabar Grey Hornbill will survive in disturbed and fragmented forest landscapes, while Great Hornbill is more vulnerable to habitat alteration. Protection and restoration of rainforest fragments and food-tree resources, besides protection of existing large fragments, will aid the conservation of hornbills in the region.

scholarly journals Species richness and relative abundance of birds in natural and anthropogenic fragments of Brazilian Atlantic forest

2004 ◽  
Vol 76 (2) ◽  
pp. 429-434 ◽  
Author(s):  
Luiz dos Anjos
Keyword(s):  
Species Richness ◽  
Atlantic Forest ◽  
Relative Abundance ◽  
Feeding Habits ◽  
Species Number ◽  
Fragmented Landscape ◽  
Forest Fragments ◽  
Forest Fragment ◽  
Forest Patches ◽  
Forest Remnants

Bird communities were studied in two types of fragmented habitat of Atlantic forest in the State of Paraná, southern Brazil; one consisted of forest fragments that were created as a result of human activities (forest remnants), the other consisted of a set of naturally occurring forest fragments (forest patches). Using quantitative data obtained by the point counts method in 3 forest patches and 3 forest remnants during one year, species richness and relative abundance were compared in those habitats, considering species groups according to their general feeding habits. Insectivores, omnivores, and frugivores presented similar general tendencies in both habitats (decrease of species number with decreasing size and increasing isolation of forest fragment). However, these tendencies were different, when considering the relative abundance data: the trunk insectivores presented the highest value in the smallest patch while the lowest relative abundance was in the smallest remnant. In the naturally fragmented landscape, time permitted that the loss of some species of trunk insectivores be compensated for the increase in abundance of other species. In contrast, the remnants essentially represented newly formed islands that are not yet at equilibrium and where future species losses would make them similar to the patches.

scholarly journals Local and Regional Effects of Pedestrians on Forest Birds in a Fragmented Landscape

The Condor ◽  
2000 ◽  
Vol 102 (2) ◽  
pp. 247-255 ◽  
Author(s):  
Esteban Fernández-Juricic
Keyword(s):  
Species Richness ◽  
Fragment Size ◽  
Species Turnover ◽  
Bird Species ◽  
Fragmented Landscape ◽  
Short Term ◽  
Regional Effects ◽  
Sturnus Unicolor ◽  
Breeding Seasons ◽  
The City

Abstract I assessed the effects of pedestrians on the distribution of forest bird species in wooded parks in the city of Madrid within and between fragments. Within fragments, increasing levels of pedestrians reduced species richness and overall abundance of individuals within circular plots. The abundance of foraging individuals of four species (Magpies Pica pica, Blackbirds Turdus merula, Starlings Sturnus unicolor, and Woodpigeon Columba palumbus) diminished when pedestrians walked near sampling plots, as well as their breeding densities in relation to increasing disturbance levels. Between fragments, after controlling for fragment size effects, pedestrian rate was negatively related to species richness in two breeding seasons. Species turnover was positively associated to mean pedestrian rate and inter-annual variability in pedestrian rate. At the species level, pedestrian rate negatively affected the probabilities of fragment occupation of 16 species beyond the effects of fragment size and isolation. Locally, the short-term behavioral responses to visitors may reduce the suitability of highly disturbed parks in such a way as to decrease breeding densities and the probabilities of fragment occupation and persistence. The effects of human disturbance in fragmented landscapes should be incorporated into management decisions as another relevant factor that may reduce habitat quality.

scholarly journals Avian diversity in a fragmented landscape of central Indian forests (Bhopal Forest Circle)

2021 ◽  
Vol 13 (5) ◽  
pp. 18177-18188
Author(s):  
Amit Kumar ◽  
Yogesh Dubey ◽  
Advait Edgaonkar
Keyword(s):  
Species Richness ◽  
Anthropogenic Disturbance ◽  
Forest Cover ◽  
Community Dynamics ◽  
Bird Species ◽  
Vital Role ◽  
Fragmented Landscape ◽  
Forest Fragments ◽  
Forest Patches ◽  
The Impact

With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern.  Therefore, this study intends to assess avifaunal biodiversity in fragmented forests.  Forest patches between the sizes of 10ha and 700ha were identified in Bhopal Forest Circle (BFC), which covers the Vindhyan plateau.  Forest patches were classified based on their size and degree of isolation.  A sample of 21 forest fragments was selected using proportional sampling.  Bird surveys were conducted using the point count method at each site.  Three replicates were taken at each site.  Avian species richness of each patch was calculated.  The results suggest that species richness is positively associated with the size of the forest patches.  Larger forest patches such as Binapur (166ha, Chao 1= 73), Sayar (107ha, Chao 1= 78) and Kalyanpura (133ha, Chao 1= 80) had relatively high species richness, except for patches including Narsinghgarh (393ha, Chao 1= 28) and Singota (184ha, Chao 1= 45) with high levels of anthropogenic disturbance.  Smaller forest patches were found to have fewer bird species, although small forest patches with lesser degrees of anthropogenic disturbance such as Lalghati (99ha, Chao 1 = 62), Lasudli (16ha, Chao 1 = 65), Ghot (36ha, Chao 1 = 53), and Nasipur (23ha, Chao 1 =52) were more diverse than other patches.  These patches were more protected due to being sacred groves (Lalghati and Lasudli) or under private ownership (Ghot and Nasipur).  A total of 131 bird species were recorded from all the sampled forest patches.  These results suggest that forest patches embedded in an agrarian landscape play a vital role in conserving biodiversity, hence conservation efforts should also be focused on these forest fragments.

scholarly journals River Floodplains as Habitat and Bio-Corridors for Distribution of Land Snails: Their Past and Present

2015 ◽  
Vol 8 (3) ◽  
pp. 23-39 ◽  
Author(s):  
Jitka Horáčková ◽  
Štěpánka Podroužková ◽  
Lucie Juřičková
Keyword(s):  
Species Richness ◽  
Vegetation Type ◽  
Natural Habitat ◽  
Geographical Location ◽  
Land Snails ◽  
Soil Reaction ◽  
Fragmented Landscape ◽  
Impatiens Glandulifera ◽  
River Floodplains ◽  
The Impact

Abstract River floodplains of Czech rivers serve as refugia to woodland or hydrophilous gastropods, in current intensively agriculturally utilised, urbanised and largely fragmented landscape. This habitat often form one of the last refuge and replace the natural habitat of these species. River floodplains also represent linear bio-corridors in landscape and allow gastropods to spread through the landscape in both directions, up and down the stream. We showed based on available fossil mollusc successions that development of the floodplain mollusc fauna took place quite different way in various river floodplains, depending on their specifics and geographical location, because especially the ones situated in the chernozem area of the Czech Republic had very different history in comparison with those in higher altitudes. The species richness and composition of recent floodplain malacofauna arises from historical development of particular area/site and depends also on environmental factors such as an elevation, humidity gradient, vegetation type and its biomass, light conditions of the site and soil reaction. Recently, the invasive plants represent a serious problem for current floodplain ecosystems; species richness and abundances of terrestrial mollusc floodplain assemblages are changing due to their effect. The impact on gastropods is species-specific and was described for the following species: Impatiens glandulifera, Fallopia japonica subsp. japonica, F. sachalinensis, F. ×bohemica.

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