Edges and gaps in mature karri forest, south-western Australia: logging effects on bird species abundance and diversity.

Forests provide bird communities with various resources, including food and habitats. Thus, forest attributes, such as size, structure, and species composition, influence the distribution and dynamics of bird species. This study was conducted to examine the association between forest condition, bird species abundance, and diversity within Chungcheongnam Province, South Korea. Zero-inflated binomial regression models were used to analyze a total of 1646 sampling points of abundance and diversity. Forest area, distance to forest edge, and tree size class were selected as covariates. Negative associations between forest area and overall bird abundance and species richness were indicated, whereas distance to forest edge was not a significant factor. This insignificance may be attributed to the relatively small, fragmented, and homogenous forest areas across the studied region. Results for individual bird species indicated that six out of the 35 major bird species had significant associations to the forest edge and three species showed a preference for the interior of the forest. The results of this study imply that other factors, such as food availability and biotic interaction, are more important when determining habitat preference in a relatively homogenous area with a long history of human disturbance.

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Patterns in diversity and composition of the microbenthos of subarctic intertidal beaches with different morphodynamics

Marine Ecology Progress Series ◽

10.3354/meps13419 ◽

2020 ◽

Vol 648 ◽

pp. 19-38

Author(s):

AI Azovsky ◽

YA Mazei ◽

MA Saburova ◽

PV Sapozhnikov

Keyword(s):

Species Abundance ◽

Abundance Ratio ◽

Wave Action ◽

Coarse Grained ◽

Sediment Properties ◽

Β Diversity ◽

Α Diversity ◽

Wide Range ◽

Similar Mode ◽

Abundance And Diversity

Diversity and composition of benthic diatom algae and ciliates were studied at several beaches along the White and Barents seas: from highly exposed, reflective beaches with coarse-grained sands to sheltered, dissipative silty-sandy flats. For diatoms, the epipelic to epipsammic species abundance ratio was significantly correlated with the beach index and mean particle size, while neither α-diversity measures nor mean cell length were related to beach properties. In contrast, most of the characteristics of ciliate assemblages (diversity, total abundance and biomass, mean individual weight and percentage of karyorelictids) demonstrated a strong correlation to beach properties, remaining low at exposed beaches but increasing sharply in more sheltered conditions. β-diversity did not correlate with beach properties for either diatoms or ciliates. We suggest that wave action and sediment properties are the main drivers controlling the diversity and composition of the intertidal microbenthos. Diatoms and ciliates, however, demonstrated divergent response to these factors. Epipelic and epipsammic diatoms exhibited 2 different strategies to adapt to their environments and therefore were complementarily distributed along the environmental gradient and compensated for each other in diversity. Most ciliates demonstrated a similar mode of habitat selection but differed in their degree of tolerance. Euryporal (including mesoporal) species were relatively tolerant to wave action and therefore occurred under a wide range of beach conditions, though their abundance and diversity were highest in fine, relatively stable sediments on sheltered beaches, whereas the specific interstitial (i.e. genuine microporal) species were mostly restricted to only these habitats.

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Tree Species Preferences of Foraging Birds in Jarrah Forest in Western Australia.

Wildlife Research ◽

10.1071/wr9850461 ◽

1985 ◽

Vol 12 (3) ◽

pp. 461 ◽

Cited By ~ 9

Author(s):

I Abbott ◽

PV Heurck

Keyword(s):

Western Australia ◽

Tree Species ◽

Bird Species ◽

Selective Logging ◽

Jarrah Forest ◽

Eucalyptus Marginata ◽

Silvicultural Treatments ◽

Species Preferences

A study of foraging by 10 bird species suggests that selective logging of large Eucalyptus marginata will only have affected Melithreptus lunatus, but that proposed silvicultural treatments, including removal of Banksia grandis, may affect several other bird species.

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How, when, and where relic DNA biases estimates of microbial diversity

10.1101/131284 ◽

2017 ◽

Cited By ~ 5

Author(s):

JT Lennon ◽

ME Muscarella ◽

SA Muscarella ◽

BK Lehmkuhl

Keyword(s):

Microbial Diversity ◽

Dna Sequences ◽

Species Abundance ◽

Rrna Gene ◽

Bacterial Dna ◽

Soil Sediment ◽

Species Abundance Distributions ◽

Abundance And Diversity ◽

Dna Pool ◽

Biased Estimates

Extracellular or “relic” DNA is one of the largest pools of nucleic acids in the mbiosphere1,2. Relic DNA can influence a number of important ecological and evolutionary processes, but it may also bias estimates of microbial abundance and diversity, which has implications for understanding environmental, engineered, and host-associated ecosystems. We developed models capturing the fundamental processes that regulate the size and composition of the relic DNA pools to identify scenarios leading to biased estimates of biodiversity. Our models predict that bias increases with relic DNA pool size, but only when the species abundance distributions (SAD) of relic and intact DNA are distinct from one another. We evaluated our model predictions by quantifying relic DNA and assessing its contribution to bacterial diversity using 16S rRNA gene sequences collected from different ecosystem types, including soil, sediment, water, and the mammalian gut. On average, relic DNA made up 33 % of the total bacterial DNA pool, but exceeded 80 % in some samples. Despite its abundance, relic DNA had no effect on estimates of taxonomic and phylogenetic diversity, even in ecosystems where processes such as the physical protection of relic DNA are common and predicted by our models to generate bias. Rather, our findings are consistent with the expectation that relic DNA sequences degrade in proportion to their abundance and therefore may contribute minimally to estimates of microbial diversity.

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Preferred temperature and thermal breadth of birds wintering in peninsular Spain – the limited effect of temperature on species distribution

10.7287/peerj.preprints.1880 ◽

2016 ◽

Author(s):

Luis M. Carrascal ◽

Sara Villén-Pérez ◽

David Palomino

Keyword(s):

Species Abundance ◽

Bird Species ◽

Effect Of Temperature ◽

Response Curves ◽

Large Variability ◽

Preferred Temperature ◽

Mean Temperature ◽

The Mean ◽

Thermal Preferences ◽

Peninsular Spain

Background. Availability of environmental energy, as measured by temperature, is expected to limit the abundance and distribution of endotherms wintering at temperate latitudes. A prediction of this hypothesis is that birds should attain their highest abundances in warmer areas. However, there may be a spatial mismatch between species preferred habitats and species preferred temperatures, so some species might end-up wintering in sub-optimal thermal environments. Methods. We model the influence of minimum winter temperature on the relative abundance of 106 terrestrial bird species wintering in peninsular Spain, at 10x10 Km2 resolution, using 95%-quantile regressions. We analyze general trends across species on the shape of the response curves, the environmental preferred temperature (at which the species abundance is maximized), the mean temperature in the area of distribution and the thermal breadth (area under the abundance-temperature curve). Results. There is a large interspecific variability on the thermal preferences and specialization of species. Despite this large variability, there is a preponderance of positive relationships between species abundance and temperature, and on average species attain their maximum abundances in areas 1.9 ºC warmer than the average temperature available in peninsular Spain. The mean temperature in the area of distribution is lower than the thermal preferences of the species, although both parameters are highly correlated. Discussion. Most species prefer the warmest environments to overwinter, which suggests that temperature imposes important restrictions to birds wintering in the Iberian Peninsula. However, most individuals overwinter in locations colder than the species thermal preferences, probably reflecting a limitation of environments combining habitat and thermal preferences. Beyond these general trends, there is a high inter-specific variation in the versatility of species using the available thermal space .

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Changes in the status and distribution of four species of parrot in the south of Western Australia during 1970-90

Pacific Conservation Biology ◽

10.1071/pc960191 ◽

1995 ◽

Vol 2 (2) ◽

pp. 191 ◽

Cited By ~ 4

Author(s):

Peter R. Mawson ◽

John L. Long

Keyword(s):

Western Australia ◽

Bird Species ◽

Fire Regimes ◽

Common Species ◽

Winter Rainfall ◽

Mail Surveys ◽

Dietary Preferences ◽

Ecological Requirements ◽

South West ◽

The Status

Mail surveys were sent to field staff of the Agriculture Protection Board of Western Australia to assess the distribution and status of four species of parrot in the agricultural region of south-west Western Australia in 1970, 1980 and 1990. The surveys indicated that the populations of the Regent Parrot (Polytelis anthopeplus) and the Western Rosella (Platycercus icterotis) have declined in range considerably since 1970. The populations of the Red-capped Parrot (Purpureicephalus spurius) and the Port Lincoln Ringneck (Barnardius zonarius) have suffered little or not at all during the same period. Factors which appear to have contributed to the observed changes in distribution and status include clearing for agriculture, dietary preferences, physiology, habitat requirements, altered fire regimes, grazing by exotic herbivores and reduced winter rainfall. These surveys have shown that species which were formerly considered common and widespread have declined with little comment having been made of these changes. The implications of this are serious, both for these formerly common species and for rarer bird species which have similar ecological requirements. The technique of mail surveys has considerable merit for quickly assessing the status of some species of birds, but will be limited by the expertise of the respondents and the degree to which the species in question can be observed.

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The Influence of Proximity of Plantation Edge on Diversity and Abundance of bird species in an exotic pine plantation in north-eastern New South Wales

Wildlife Research ◽

10.1071/wr9910299 ◽

1991 ◽

Vol 18 (3) ◽

pp. 299 ◽

Cited By ~ 25

Author(s):

GN Curry

Keyword(s):

New South ◽

Structural Characteristics ◽

New South Wales ◽

Bird Species ◽

Native Forest ◽

Feeding Guild ◽

South Wales ◽

North Eastern ◽

Plantation Life ◽

Abundance And Diversity

Data were collected in summer and winter in a 15-year-old plantation of Pinus taeda, at Clouds Creek, north-eastern New South Wales. In summer, diversity and abundance of bird species declined over a distance of 900 m into the plantation. However, in winter this progressive decline in bird densities was limited to within the first 200 m of the plantation periphery. At greater distances into the plantation, the floristic and structural characteristics of the vegetation (including windrows) were of more importance than the proximity of the plantation edge in accounting for variations in the abundance and diversity of birds. Food for insectivorous birds (the dominant feeding guild) is probably restricted in the plantation because few local species of invertebrates are likely to be adapted to living on exotic pines; invertebrate mobility as well as abundance is probably less in winter, so that fewer invertebrates enter the plantation from adjacent native forest. Windrows are an important habitat feature contributing to the diversity and abundance of birds within plantations, probably serving as 'corridors' through the alien habitat of exotic pines, thus enabling birds to range further into plantations. For approximately 40 per cent of the plantation life cycle, the influence of proximity of plantation edge on diversity and abundance of bird species is probably of limited importance, particularly in winter. Reducing plantation size in order to increase the diversity and abundance of bird species is not realistic, because plantations would have to be very small. Instead, emphasis should be placed on increasing the structural and floristic diversity of plantations by creating a broad range of successional stages throughout the plantation complex, by enhancing the habitat value of windrows, and by retaining native vegetation within and near plantations.

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Comparison of Bird Populations in Remnants of Wandoo Woodland and in Adjacent Farmland.

Wildlife Research ◽

10.1071/wr9870331 ◽

1987 ◽

Vol 14 (3) ◽

pp. 331 ◽

Cited By ~ 6

Author(s):

GW Arnold ◽

RA Maller ◽

R Litchfield

Keyword(s):

Western Australia ◽

Seasonal Changes ◽

Bird Species ◽

Bird Populations ◽

Scattered Trees ◽

Open Woodland

Data were obtained during 2 yr at Baker's Hill, Western Australia, in farmland with no trees, scattered trees or clumps of trees and 3 types of open woodland. There were differences in the number of bird species found in each habitat, ranging from 25 in woodland habitats to 11 in open farmland. In autumn, there were more aerial feeders in open farmland and farmland with few trees than in farmland with many trees and woodland, but fewer in spring. There were more ground-feeding seed-eaters in farmland with trees than elsewhere, except in autumn. There were large seasonal reciprocal changes in the numbers of thornbills in farmland with many trees and woodland, indicating movement between habitats. Within the woodland habitats there were only small seasonal changes, but there were large differences in numbers of some groups between the 3 habitats.

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