Bird assemblages in wildlife habitat strips in a Tasmanian plantation matrix

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.

2019 ◽  
Vol 5 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jukka Suhonen ◽  
Jukka Jokimäki

Abstract Temporal dynamics of local assemblages depend on the species richness and the total abundance of individuals as well as local departure and arrival rates of species. We used urban bird survey data collected from the same 31 study plots and methods during three winters (1991–1992; 1999–2000 and 2009–2010) to analyze the temporal relationship between bird species richness and total number of individuals (abundance). We also evaluated local departures and arrivals of species in each assemblage. In total, 13,812 individuals of 35 species were detected. The temporal variation in bird species richness followed the variation in the total number of individuals. The numbers of local departure and arrival events were similar. Also, the mean number of individuals of the recently arrived species (8.6) was almost the same as the mean number of individuals of the departed species (8.2). Risk of species departure was inversely related to number of individuals. Local species richness increased by one species when the total abundance of individuals increased by around 125 individuals and vice versa. Our results highlight the important role of local population departures and arrivals in determining the local species richness-abundance dynamics in human-dominated landscapes. Local species richness patterns depend on the total number of individuals as well as both the departure-arrival dynamics of individual species as well as the dynamics of all the species together. Our results support the more individuals hypothesis, which suggests that individual-rich assemblages have more species.


2011 ◽  
Vol 38 (6) ◽  
pp. 482 ◽  
Author(s):  
Susan F. Gould

Context Rehabilitation is increasingly being promoted as a strategy for minimising and even reversing biodiversity loss. Many rehabilitation strategies that aim to provide habitat focus entirely on establishing vegetation. Successful vegetation establishment, however, does not necessarily provide habitat that is ecologically equivalent to that removed by vegetation clearing. Quantitative understanding of faunal responses to rehabilitation is required if rehabilitation techniques are to be refined and deliver desired biodiversity outcomes. Aims I aimed to assess the extent to which post-mining rehabilitation restores bird habitat equivalent to that removed in the mining process on the Weipa bauxite plateau. Methods The composition, abundance and richness of bird assemblages were compared between native forest sites and a 23-year chronosequence of post-mining rehabilitation sites. Native forest sites were made up of three Weipa bauxite plateau land units, including the land unit that represents pre-mining native forest, and two land units that are considered to be potential analogues for the post-mining landscape. Key results Bird abundance and bird species richness increased with rehabilitation age. Bird species richness in the two oldest age classes of mine rehabilitation was similar to values obtained from pre-mining native forest and post-mining landscape analogue sites. The composition of bird assemblages, however, was significantly different. Of all the bird species observed, 25% occurred exclusively in native forest sites, 19% occurred exclusively in mine-rehabilitation sites, and the remaining 56% were recorded in both native forest and mine-rehabilitation sites. Site bird-detection rates were significantly related to site vegetation structure, with inter-specific differences in bird response. Conclusions Post-mining rehabilitation at Weipa has partially made up for the loss of habitat caused by clearing for mining. Twenty-three years after rehabilitation commenced, however, a clear residual impact on biodiversity remains, with a third of native forest birds absent from mine rehabilitation, including several native forest specialists. Implications Rehabilitation can partially make up for biodiversity losses caused by the initial loss of habitat. There is no evidence, however, that rehabilitation can achieve ‘no net loss’. Reliance on rehabilitation to achieve conservation outcomes does not address the fact that many fauna species require resources that are found only in mature forest.


2021 ◽  
Author(s):  
Festus Oluwatimileyin Adegbola ◽  
Taiye Adeniyi Adeyanju ◽  
Soladoye B. Iwajomo ◽  
Ibukunoluwa Augustine Ayodele

Urbanisation is considered as one of the most profound threat to wildlife, with habitat loss and fragmentation being predominant. This study assessed the impacts of urbanisation on richness, abundance of bird species within Ibadan metropolis, Nigeria. A uniform grid of 500 square meters was installed on the map of Ibadan Metropolis using QGIS to produce 499 grid points distributed across the five urban local governments. 100 grids were selected randomly, identified with mapinR software application and surveyed with 5 point counts within each gird, established at 200m interval to avoid double counting. Each point count was observed for 5 minutes using a pair of 8x42mm binoculars within a 50m radius. Habitat variables like number of buildings, trees, paved roads, communication masts were also recorded. A total number of 56 species of birds were observed at the end of the assessment, classified into 30 families. The test of statistics showed that there was no statistically significant difference in bird species richness between the Local Governments. The test of statistics showed that there was no statistically significant difference in bird species abundance between the local governments. The test of between-subjects effects revealed that there were no statistical significant effects when all the habitat variables were computed in the model on species richness. The number of paved roads and number of vehicles showed a significant effect on bird species abundance while others variables in the model did not exact statistically significant effects on bird species abundance. The study therefore concluded that habitat actions due to urbanisation have not affected the richness and abundance of birds species found in all the local governments. The only habitat variables that have currently exacted significant effect on species abundance within the metropolis are number of vehicles and paved roads.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Tatiana Lemos da Silva ◽  
Edilaine Lemes Marques ◽  
Edson Guilherme

The present study evaluated the characteristics of the understory bird fauna of four fragments ofterra firmeforest in eastern Acre, Brazil, that were impacted by wildfires in 2005. The study investigated the species richness and the composition of trophic guilds using mist-netting on eight transects (four in burned plots and four in control plots in the same forest fragments). Eight plots (0.12 ha) were also established parallel to each transect to record the number of live trees (DBH ≥ 10 cm), palms, and dead trees. Bamboo stems were quantified in 0.024 ha subplots. No significant difference was found between burned and control plots in the species richness or abundance of birds, nor was any significant pattern found in the NMDS ordination of the composition of the communities or guilds. The Principal Components Analysis (PCA) found that the burned plots were physiognomically distinct, due principally to the number of bamboo stems and dead trees. Multiple regressions based on the PCA scores and bird species richness and abundance found no significant trends. The findings of the present study indicate that the understory bird assemblage of the areas affected by a single wildfire in 2005 had almost totally recuperated eight years after this event.


2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.


2021 ◽  
Vol 127 ◽  
pp. 107774
Author(s):  
Martina L. Hobi ◽  
Laura S. Farwell ◽  
Maxim Dubinin ◽  
Dmitrij Kolesov ◽  
Anna M. Pidgeon ◽  
...  

2008 ◽  
Vol 54 (No. 4) ◽  
pp. 189-193
Author(s):  
M. Żmihorski

Clearcuts are one of the results of forest management. The aim of this study was to assess the effect of clearcuts on bird communities in a managed forest in Western Poland. I applied the method of point transect counts. 20 points were located near clearcuts (less than 100 m from the nearest clearcut) and 25 points in the forest interior. In total, 36 bird species were recorded. On average, I found 9.20 bird species at points located near clearcuts and 6.72 species at points situated in the forest interior, and the difference was significant. The cumulative number of bird species for a given number of sampling points in the vicinity of clearcuts was higher than in the forest interior. The obtained results indicate that in managed, even-aged forests the generation of clearcuts can lead to an increase in local bird species richness.


Biologia ◽  
2014 ◽  
Vol 69 (2) ◽  
Author(s):  
Lenka Hajzlerová ◽  
Jiří Reif

AbstractImpacts of invasive alien plant species are threatening biodiversity worldwide and thus it is important to assess their effects on particular groups of organisms. However, such impacts were studied mostly in case of plant or invertebrate communities and our understanding the response of vertebrate species to plant invasions remains incomplete. To improve our knowledge in this respect, we studied bird communities in riparian vegetation along the rivers with different levels of Reynoutria spp. invasion in the Czech Republic. These findings will be interesting for basic ecology enhancing our knowledge of consequences of plant invasions, as well as for conservation practice. We surveyed understory bird species in 26 vegetation blocks along parts of three rivers running from the Beskydy Mountains in spring 2011. We used principal component analysis to assess vegetation structure of particular blocks and the first axis ordinated the blocks according to the degree of invasion by Reynoutria spp. Using generalized linear mixed-effects models we found that counts of Motacilla cinerea, Cinclus cinclus and Sylvia borin, as well as the total bird species richness, significantly decreased with increasing degree of Reynoutria spp. invasion, while Acrocephalus palustris showed the opposite pattern. These results suggest that Reynoutria spp. impacts negatively on the species strictly bond with river banks and habitats specialists, whereas habitat generalist species like Sylvia atricapilla were not affected. Preference of Acrocephalus palustris for Reynoutria spp. corroborates affinity of this species to large invasive herbs observed also in other studies. Our study showed that Reynoutria spp. invasion can reduce species richness of understory birds in riparian communities. Although the distribution of this plant species is still quite limited in central Europe, our results suggest that its more widespread occurrence could potentially threat some river bank bird species. Therefore, we urge for development of management actions that will act counter the Reynoutria spp. invasion.


2014 ◽  
Vol 369 (1643) ◽  
pp. 20130197 ◽  
Author(s):  
Véronique St-Louis ◽  
Anna M. Pidgeon ◽  
Tobias Kuemmerle ◽  
Ruth Sonnenschein ◽  
Volker C. Radeloff ◽  
...  

Applications of remote sensing for biodiversity conservation typically rely on image classifications that do not capture variability within coarse land cover classes. Here, we compare two measures derived from unclassified remotely sensed data, a measure of habitat heterogeneity and a measure of habitat composition, for explaining bird species richness and the spatial distribution of 10 species in a semi-arid landscape of New Mexico. We surveyed bird abundance from 1996 to 1998 at 42 plots located in the McGregor Range of Fort Bliss Army Reserve. Normalized Difference Vegetation Index values of two May 1997 Landsat scenes were the basis for among-pixel habitat heterogeneity (image texture), and we used the raw imagery to decompose each pixel into different habitat components (spectral mixture analysis). We used model averaging to relate measures of avian biodiversity to measures of image texture and spectral mixture analysis fractions. Measures of habitat heterogeneity, particularly angular second moment and standard deviation, provide higher explanatory power for bird species richness and the abundance of most species than measures of habitat composition. Using image texture, alone or in combination with other classified imagery-based approaches, for monitoring statuses and trends in biological diversity can greatly improve conservation efforts and habitat management.


Ecosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
A. Andrikou‐Charitidou ◽  
G. Boutsis ◽  
E. Karadimou ◽  
A. S. Kallimanis

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