Effect of the Weed Chrysanthemoides monilifera (Bitou Bush) on Bird Communities

1997 ◽  
Vol 24 (6) ◽  
pp. 727 ◽  
Author(s):  
Kristine French ◽  
Anita Zubovic
Keyword(s):  
Species Richness ◽  
Resource Use ◽  
Bird Communities ◽  
Differential Impact ◽  
Site Use ◽  
Species Richness And Abundance ◽  
Foraging Guild ◽  
The Impact ◽  
Positive Effect ◽  
Bitou Bush

Bird communities in native coastal woodland were compared with those in woodland infested with Chrysanthemoides monilifera rotundata (bitou bush) in order to determine the impact of infestations of this weed on birds. Little evidence was found to suggest that bitou bush negatively affected the bird communities as a whole. Overall, the total number of birds in each type of habitat did not differ while numbers of species differed only at one area. Weed infestations have a differential impact on foraging groups. Canopy-feeding generalists and understorey insectivores showed differences in abundance and species richness in a few areas, with greater numbers in weed sites than in native sites. Temporal variation in weed-site use was also evident for canopy foragers. For these groups, weed infestations are providing at least some resources, although the details of resource use need to be investigated further. Species richness and abundance of birds relying almost exclusively on plant material were negatively affected by weed infestations, indicating that this foraging guild may not be provided with adequate resources in weed-infested habitats. Similarly, although numbers were low, scavengers and raptors also showed lower abundances and species richness in weed-infested habitats. For these foraging groups, management programmes to rehabilitate weed-infested habitats are likely to have a positive effect on numbers.

Potential impacts of fire and grazing in an endangered ecological community: plant composition and shrub and eucalypt regeneration in Cumberland Plain Woodland

2004 ◽  
Vol 52 (1) ◽  
pp. 23 ◽  
Author(s):  
Sarah J. Hill ◽  
Kristine French
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Species Interactions ◽  
Ecological Community ◽  
Plant Composition ◽  
Shrub Species ◽  
Pre Treatment ◽  
Species Richness And Abundance ◽  
The Impact ◽  
Canopy Species

Exclosure plots were used to determine the effect of fire and grazing on the structure of a grassy-woodland community. Eighteen months after fire and fence treatments were applied, the species richness, cover and composition of shrubs, trees, herbs and grasses were assessed and compared to pre-treatment censuses. Unburned plots had fewer shrub species and a lower abundance of shrubs, indicating the importance of fire in promoting regeneration of shrub species. Eucalypt species were more abundant and richer following the wildfire burn in summer, suggesting timing of fires is an important aspect in the establishment of the canopy species. Interactions between fire and grazing were found for the abundance of eucalypts (although weak) and resprouting eucalypts, suggesting a subtle interaction between fire and grazing shortly after fire. There was no effect of grazing and no interaction effect between fire and grazing on shrub species richness and abundance or tree species richness and seedling abundance.All plots showed a change in species composition despite treatment, and 46 species (32% of total richness) were recorded only in the final survey. The high rainfall during the 18-month study is likely to be an important factor in facilitating the establishment of species following all disturbances. This may have ameliorated the impact of grazing as abundant food was available throughout the woodland. The interaction between fire and grazing may be more important in structuring these grassy communities during periods of lower rainfall.

scholarly journals Impact of Horizontal Edge–Interior and Vertical Canopy–Understory Gradients on the Abundance and Diversity of Bark and Woodboring Beetles in Survey Traps

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 573 ◽  
Author(s):  
Jon Sweeney ◽  
Cory Hughes ◽  
Vincent Webster ◽  
Chantelle Kostanowicz ◽  
Reginald Webster ◽  
...  
Keyword(s):  
Species Richness ◽  
Field Trapping ◽  
Horizontal Edge ◽  
Forest Gaps ◽  
Forest Insects ◽  
Trap Location ◽  
Abundance And Diversity ◽  
Species Richness And Abundance ◽  
The Impact ◽  
Gradient Effects

Semiochemical-baited intercept traps are important tools used to collect information about the presence/absence and population dynamics of forest insects. The performance of these tools is influenced by trap location along both horizontal edge–interior and vertical understory–canopy gradients. Consequently, the development of survey and detection programs requires both the development of effective traps and semiochemical lures but also deployment protocols to guide their use. We used field trapping experiments to examine the impact of both horizontal edge–interior and vertical understory–canopy gradients and their interactions with the species richness and abundance of Buprestidae, Cerambycidae and Curculionidae. Both gradients had significant effects on the diversity and abundance of all three families collected in traps and the pattern of gradient effects differed between the two experiments. In the first experiment, traps were deployed along transects involving large (>100 m) forest gaps and in the second experiment traps transected small (ca. 15 m) forest gaps. These results were consistent with the idea that gradient effects on the abundance and diversity of these three families of forest Coleoptera are context dependent. The results of this study suggest that monitoring programs for bark and woodboring beetles should deploy traps at multiple locations along both vertical understory–canopy and horizontal edge–interior gradients.

scholarly journals Local and landscape features constrain the trait and taxonomic diversity of urban bees

2021 ◽  
Author(s):  
Hamutahl Cohen ◽  
Monika Egerer ◽  
Summer-Solstice Thomas ◽  
Stacy M. Philpott
Keyword(s):  
Species Richness ◽  
Taxonomic Diversity ◽  
Phenotypic Traits ◽  
Urban Landscapes ◽  
Wild Bees ◽  
Landscape Features ◽  
Landscape Scales ◽  
Impact Of Urbanization ◽  
Species Richness And Abundance ◽  
The Impact

Abstract Context There is concern that urbanization threatens bees, a diverse group of economic importance. The impact of urbanization on bees is likely mediated by their phenotypic traits. Objectives We examine how urban cover and resource availability at local and landscape scales influences both species taxonomic and functional diversity in bees. Methods We used a combination of aerial netting and pan traps across six sampling periods to collect wild bees in 18 urban gardens spanning more than 125 km of the California central coast. We identified 3537 specimens to genus and, when possible, to species to obtain species richness and abundance at each site. For each species we measured a suite of bee traits, including body size, sociality, nesting location, nesting behavior, pollen-carrying structure, parasitism, and lecty. Results We found that increased garden size was positively associated with bee species richness and abundance. Somewhat counterintuitively, we found that urban cover surrounding gardens (2 km) was positively associated with bee species richness. Urban cover was also associated with the prevalence of certain bee traits, such as bees that excavate nests over those who rent, and bees with non-corbiculate structures. We suggest that urban habitats such as gardens can host a high number of bee species, but urbanization selects for species with specific traits. Conclusions These findings illustrate that local and landscape features both influence bee abundance, species richness, and the frequency of specific traits. We highlight the importance of trait-based approaches for assessing biodiversity in urban landscapes, and suggest conceptualizing urbanization as a process of habitat change rather than habitat loss.

Changes in woodland bird communities as replanted woodland matures

2017 ◽  
Vol 23 (4) ◽  
pp. 359 ◽  
Author(s):  
S. J. S. Debus ◽  
W. K. Martin ◽  
J. M. Lemon
Keyword(s):  
Species Richness ◽  
Agricultural Land ◽  
New South ◽  
Bird Communities ◽  
Agricultural Fields ◽  
Woodland Birds ◽  
Nectar Feeding ◽  
South Wales ◽  
Manorina Melanocephala ◽  
Species Richness And Abundance

Small patches of woodland were progressively established on degraded agricultural land near Gunnedah, northern New South Wales, on the heavily cleared Liverpool Plains. Birds were resurveyed in the plantings, and in agricultural fields (cropping and pasture) and remnant woodland, in 2011–12, 10 years after initial surveys in 2000–01. The plantings in the later survey were 60, 18, 16 and 13 years old, with a shrub layer included in the three youngest cohorts. The survey sites (total 14 ha planted, all within 200 m of remnant woodland) were paired 1-ha plots in each vegetation category. Birds were surveyed by 30-min area searches of each plot eight times over all seasons, using the same plots, procedure and observer as before. In all, 73 species were recorded in the later survey (versus 72 in the earlier survey), for a total of 87 species over both survey periods, with 58 species in 2011–12 (versus 54 in 2000–01) in the plantings; eight of 15 new species visited or colonised the maturing plantings. Avian species richness and abundance increased from the cleared agricultural plots through the progressively older plantings to resemble those in the remnant woodland. Between the first and second surveys, bird communities in the younger plantings converged with those in the older plantings and woodland. The nectar-feeding, foliage-feeding and ground-feeding insectivore guilds benefitted most, having increased in frequency in, or moved into, the younger cohorts of plantings (>13 years old), or both. Several threatened and other declining woodland birds visited, increased in or colonised the plantings. However, noisy miners (Manorina melanocephala) progressively occupied a few plots and excluded some other birds.

Avian recolonization of eastern Canadian bogs after peat mining

1998 ◽  
Vol 76 (6) ◽  
pp. 989-997 ◽  
Author(s):  
André Desrochers ◽  
Line Rochefort ◽  
Jean-Pierre L Savard
Keyword(s):  
Species Richness ◽  
Vegetation Structure ◽  
Bird Species ◽  
Safety Net ◽  
Bird Communities ◽  
Percent Cover ◽  
Bird Species Richness ◽  
Peat Mining ◽  
Mining History ◽  
Species Richness And Abundance

To evaluate the potential of bog ecosystems to recover following peat mining, we compared bird species richness,abundance, and assemblages and vegetation among naturally revegetated and undisturbed bog sites in southeastern Quebec.Based on mining history, we selected 28 sites (12 natural, 9 abandoned after blockcut extraction, and 7 abandoned after vacuumextraction) in 15 bogs. We estimated percent cover for six vegetation strata in 106 plots with 100 m radius, on which bird pointcounts were conducted in 1993 and 1996. Vegetation structure differed significantly between natural, post-blockcut andpost-vacuum sites. While vegetation cover was almost complete in natural sites, abandoned sites, especially post vacuum, wereless vegetated, even after 20 years. Bird species richness and abundance were similar in natural and post-blockcut sites andboth were higher than in post-vacuum sites. Ten of the 28 species studied in detail responded to site perturbation. Among them,the Palm Warbler was most closely associated with natural sites. Bird communities were closely associated with vegetationstructure. Communities of post-blockcut sites were more similar to those of natural bogs than were bird communities ofpost-vacuum sites. Since the blockcut method of peat mining is no longer economically feasible, we conclude that bog habitatrestoration should be accompanied by a preservation “safety net” area to counteract the lasting effect of vacuum peat mining onbird species assemblages.

scholarly journals Quantifying Effects of Spatial Heterogeneity of Farmlands on Bird Species Richness by Means of Similarity Index Pairwise

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Federico Morelli
Keyword(s):  
Species Richness ◽  
Spatial Heterogeneity ◽  
Central Italy ◽  
Bird Species ◽  
Similarity Index ◽  
Bird Communities ◽  
Bird Species Richness ◽  
Bird Richness ◽  
Farmland Bird ◽  
The Impact

Many studies have shown how intensification of farming is the main cause of loss biodiversity in these environments. During the last decades, agroecosystems in Europe have changed drastically, mainly due to mechanization of agriculture. In this work, species richness in bird communities was examined on a gradient of spatial heterogeneity of farmlands, in order to quantify its effects. Four categories of farmland spatial heterogeneity were defined, based on landscape and landuse parameters. The impact of features increasing the spatial heterogeneity was quantified comparing the similarity indexes between bird communities in several farmlands of Central Italy. The effects of environmental variables on bird richness were analyzed using GLM. The results highlighted that landscape features surrogates of high nature values (HNVs) of farmlands can increase more than 50% the bird species richness. The features more related to bird richness were hedgerows, scattered shrubs, uncultivated patches, and powerlines. The results confirm that the approach based on HNV for evaluating the farmlands is also suitable in order to study birds’ diversity. However, some species are more sensitive to heterogeneity, while other species occupy mainly homogeneous farmlands. As a consequence, different conservation methods must be considered for each farmland bird species.

Functional evenness of bird communities varies along the elevational gradient in Europe: Conservation implications

2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina
Keyword(s):  
Species Richness ◽  
Elevation Gradient ◽  
Bird Species ◽  
Elevational Gradient ◽  
Negative Association ◽  
Bird Communities ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Large Spatial Scale ◽  
Functional Evenness

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.

Impact of Digitalization on Service Work in Knowledge-Intensive Business Services: An Empirical Study in Tax Consultancies

2019 ◽  
Vol 3 (4) ◽  
pp. 209-222
Author(s):  
Philipp K. Görs ◽  
Henning Hummert ◽  
Anne Traum ◽  
Friedemann W. Nerdinger
Keyword(s):  
Work Engagement ◽  
Service Work ◽  
Psychological Consequences ◽  
Business Services ◽  
Knowledge Intensive Business Services ◽  
Positive Effects ◽  
Knowledge Intensive ◽  
The Impact ◽  
Positive Effect ◽  
Special Case

Digitalization is a megatrend, but there is relatively little knowledge about its consequences for service work in general and specifically in knowledge-intensive business services (KIBS). We studied the impact of digitalization on psychological consequences for employees in tax consultancies as a special case of KIBS. We compare two tax consulting jobs with very different job demands, those of tax consultants (TCs) and assistant tax consultants (ATCs). The results show that the extent of digitalization at the workplace level for ATCs correlates significantly positively with their job satisfaction. For TCs, the same variable correlates positively with their work engagement. These positive effects of digitalization are mediated in the case of ATCs by the impact on important job characteristics. In the case of TCs, which already have very good working conditions, the impact is mediated by the positive effect on self-efficacy. Theoretical and practical consequences of these results are discussed.

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