Responses of Great Horned Owls (Bubo virginianus), Barred Owls (Strix varia), and Northern Saw-whet Owls (Aegolius acadicus) to forest cover and configuration in an agricultural landscape in Alberta, Canada

2008 ◽  
Vol 86 (10) ◽  
pp. 1165-1172 ◽  
Author(s):  
S. R. Grossman ◽  
S. J. Hannon ◽  
A. Sánchez-Azofeifa
Keyword(s):  
Forest Cover ◽  
Agricultural Landscape ◽  
Agricultural Landscapes ◽  
Forest Patch ◽  
Bubo Virginianus ◽  
Strix Varia ◽  
Area Variation ◽  
Aegolius Acadicus ◽  
Abundance And Distribution ◽  
Barred Owls

Studies on the effects of forest fragmentation on birds have focussed primarily on passerines, with few studies on owls. We assessed the influence of forest amount and configuration on the abundance and distribution of three species of forest owls, Great Horned Owl ( Bubo virginianus (Gmelin, 1788)), Barred Owl ( Strix varia Barton, 1799), and Northern Saw-whet Owl ( Aegolius acadicus (Gmelin, 1788)), in agricultural landscapes with varying amounts of forest cover in central Alberta, Canada. All three species were positively associated with forest cover: Barred Owls were most prevalent in landscapes with >66% forest cover, Great Horned Owls in landscapes with between 36% and 65% forest cover, and Northern Saw-whet Owls in landscapes with between 16% and 100% forest cover. Regression models containing configuration variables were chosen as best models using AIC for all three species. Great Horned Owls were most abundant in landscapes with high heterogeneity: more forest–nonforest edges and higher forest patch area variation. Barred Owls were more likely to occur in landscapes with larger forest patch areas and Northern Saw-whet Owls were more abundant in landscapes that were more connected. These relationships are consistent with predictions based on body size of owls and local habitat relationships described in the literature.

scholarly journals Landscape and microhabitat features determine small mammal abundance in forest patches in agricultural landscapes

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12306
Author(s):  
Luca Dorigo ◽  
Francesco Boscutti ◽  
Maurizia Sigura
Keyword(s):  
Small Mammals ◽  
Agricultural Landscape ◽  
Species Abundance ◽  
Strong Relationship ◽  
Species Interaction ◽  
Agricultural Landscapes ◽  
Ecosystem Functions ◽  
Forest Patch ◽  
Generalist Species ◽  
Ecological Requirements

Intensification of agricultural landscapes represent a major threat for biodiversity conservation also affecting several ecosystem services. The natural and semi-natural remnants, available in the agricultural matrix, represent important sites for small mammals and rodents, which are fundamental for sustaining various ecosystem functions and trophic chains. We studied the populations of two small mammals (Apodemus agrarius, A. sylvaticus) to evaluate the effects of landscape and habitat features on species abundance along a gradient of agricultural landscape intensification. The study was performed in Friuli Venezia Giulia (north-eastern Italy) during 19 months, in 19 wood remnants. Species abundance was determined using Capture-Mark-Recapture (CMR) techniques. In the same plots, main ecological parameters of the habitat (at microhabitat and patch scale) and landscape were considered. Abundance of A. agrarius increased in landscapes with high extent of permanent crops (i.e., orchards and poplar plantations) and low content of undecomposed litter in the wood understory. Instead, A. sylvaticus, a more generalist species, showed an opposite, albeit less strong, relationship with the same variables. Both species were not affected by any landscape structural feature (e.g., patch shape, isolation). Our findings showed that microhabitat features and landscape composition rather than wood and landscape structure affect populations’ abundance and species interaction. The opposite response of the two study species was probably because of their specific ecological requirements. In this light, conservation management of agricultural landscapes should consider the ecological needs of species at both landscape and habitat levels, by rebalancing composition patterns in the context of ecological intensification, and promoting a sustainable forest patch management.

Occupancy and abundance of free-roaming cats in a fragmented agricultural ecosystem

2019 ◽  
Vol 46 (4) ◽  
pp. 277
Author(s):  
Sarah C. Webster ◽  
Zachary H. Olson ◽  
James C. Beasley
Keyword(s):  
Native Species ◽  
Agricultural Landscape ◽  
Agricultural Landscapes ◽  
Agricultural Ecosystem ◽  
Forest Patches ◽  
Forest Patch ◽  
Entire Study ◽  
Agricultural Ecosystems ◽  
Occupancy Probability ◽  
Rural Environments

Context Free-roaming domestic cats are a widespread invasive species, occurring throughout the globe in urban and rural environments alike. However, robust estimates of cat occupancy and abundance, especially in rural, agricultural landscapes, are largely unknown. Aims To estimate cat occupancy and abundance within forested habitat in a fragmented agricultural region of Indiana, USA. Methods Free-roaming cats in 55 forest patches were captured from 2004 to 2010 to assess the effects of landscape attributes on cat occupancy probabilities. During 2009–10 abundance of cats in each habitat patch was estimated based on natural markings of captured individuals. Key results Across the entire study (2004–10) cats in 50 of the 55 patches were detected, but detections varied temporally and spatially. Average occupancy probability was estimated at Ψ = 0.773 (s.e. = 0.109), and detection probability was estimated as P = 0.204 (s.e. = 0.012). Distance to human structures and forest patch isolation both were found to negatively influence cat occupancy. In total, 57 individual cats were captured in 2009 and 55 in 2010, when unique individuals were distinguished. Across all forest patches, average cat abundance was n = 1.08 in 2009 and n = 0.91 in 2010, ranging from 0 to 7 among sampled patches. Conclusions Overall, the distribution of free-roaming cats across a rural agricultural landscape varied temporally and was associated with proximity to human structures and the proximity of other forest habitat. Similarly, abundance was found to vary spatially and temporally. Implications The findings suggest free-roaming cats are widespread throughout agricultural ecosystems, but their distribution is dynamic and non-random. Additionally, the potential for cats to impact native fauna inhabiting remnant forest patches is high in fragmented agricultural ecosystems due to the concentration of native species utilising these patches. Further research is needed to determine the effects free-roaming cats are having on native species in human-dominated, rural ecosystems, and what conservation measures might be implemented to best mitigate any impacts.

scholarly journals The Relict Ecosystem of Maytenus senegalensis subsp. europaea in an Agricultural Landscape: Past, Present and Future Scenarios

Land ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Antonio J. Mendoza-Fernández ◽  
Fabián Martínez-Hernández ◽  
Esteban Salmerón-Sánchez ◽  
Francisco J. Pérez-García ◽  
Blas Teruel ◽  
...  
Keyword(s):  
Plant Communities ◽  
Ecological Niche ◽  
Agricultural Landscape ◽  
Agricultural Landscapes ◽  
Eastern Coast ◽  
Ecological Value ◽  
Distribution Models ◽  
European Continent ◽  
Major Interest ◽  
Maytenus Senegalensis

Maytenus senegalensis subsp. europaea is a shrub belonging to the Celastraceae family, whose only European populations are distributed discontinuously along the south-eastern coast of the Iberian Peninsula, forming plant communities with great ecological value, unique in Europe. As it is an endangered species that makes up plant communities with great palaeoecological significance, the development of species distribution models is of major interest under different climatic scenarios, past, present and future, based on the fact that the climate could play a relevant role in the distribution of this species, as well as in the conformation of the communities in which it is integrated. Palaeoecological models were generated for the Maximum Interglacial, Last Maximum Glacial and Middle Holocene periods. The results obtained showed that the widest distribution of this species, and the maximum suitability of its habitat, occurred during the Last Glacial Maximum, when the temperatures of the peninsular southeast were not as contrasting as those of the rest of the European continent and were favored by higher rainfall. Under these conditions, large territories could act as shelters during the glacial period, a hypothesis reflected in the model’s results for this period, which exhibit a further expansion of M. europaea’s ecological niche. The future projection of models in around 2070, for four Representative Concentration Pathways according to the fifth report of the Intergovernmental Panel on Climate Change, showed that the most favorable areas for this species would be Campo de Dalías (southern portion of Almería province) as it presents the bioclimatic characteristics of greater adjustment to M. europaea’s ecological niche model. Currently, some of the largest specimens of the species survive in the agricultural landscapes in the southern Spain. These areas are almost totally destroyed and heavily altered by intensive agriculture greenhouses, also causing a severe fragmentation of the habitat, which implies a prospective extinction scenario in the near future.

scholarly journals Predation on Drosophila suzukii within Hedges in the Agricultural Landscape

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 305
Author(s):  
Alexandra Siffert ◽  
Fabian Cahenzli ◽  
Patrik Kehrli ◽  
Claudia Daniel ◽  
Virginie Dekumbis ◽  
...  
Keyword(s):  
Agricultural Landscape ◽  
Vital Role ◽  
Agricultural Landscapes ◽  
Gut Content ◽  
Drosophila Suzukii ◽  
Natural Habitats ◽  
Host Fruit ◽  
Molecular Gut Content Analysis ◽  
Wild Fruits ◽  
Diverse Community

The invasive Drosophila suzukii feeds and reproduces on various cultivated and wild fruits and moves between agricultural and semi-natural habitats. Hedges in agricultural landscapes play a vital role in the population development of D. suzukii, but also harbor a diverse community of natural enemies. We investigated predation by repeatedly exposing cohorts of D. suzukii pupae between June and October in dry and humid hedges at five different locations in Switzerland. We sampled predator communities and analyzed their gut content for the presence of D. suzukii DNA based on the COI marker. On average, 44% of the exposed pupae were predated. Predation was higher in dry than humid hedges, but did not differ significantly between pupae exposed on the ground or on branches and among sampling periods. Earwigs, spiders, and ants were the dominant predators. Predator communities did not vary significantly between hedge types or sampling periods. DNA of D. suzukii was detected in 3.4% of the earwigs, 1.8% of the spiders, and in one predatory bug (1.6%). While the molecular gut content analysis detected only a small proportion of predators that had fed on D. suzukii, overall predation seemed sufficient to reduce D. suzukii populations, in particular in hedges that provide few host fruit resources.

scholarly journals Drivers of Bornean Orangutan Distribution across a Multiple-Use Tropical Landscape

2021 ◽  
Vol 13 (3) ◽  
pp. 458
Author(s):  
Sol Milne ◽  
Julien G. A. Martin ◽  
Glen Reynolds ◽  
Charles S. Vairappan ◽  
Eleanor M. Slade ◽  
...  
Keyword(s):  
Forest Cover ◽  
Food Resource ◽  
Multiple Use ◽  
Natural Forests ◽  
Bornean Orangutan ◽  
Aerial Surveys ◽  
Significant Difference ◽  
The Difference ◽  
Fig Trees ◽  
Abundance And Distribution

Logging and conversion of tropical forests in Southeast Asia have resulted in the expansion of landscapes containing a mosaic of habitats that may vary in their ability to sustain local biodiversity. However, the complexity of these landscapes makes it difficult to assess abundance and distribution of some species using ground-based surveys alone. Here, we deployed a combination of ground-transects and aerial surveys to determine drivers of the critically endangered Bornean Orangutan (Pongo pygmaeus morio) distribution across a large multiple-use landscape in Sabah, Malaysian Borneo. Ground-transects and aerial surveys using drones were conducted for orangutan nests and hemi-epiphytic strangler fig trees (Ficus spp.) (an important food resource) in 48 survey areas across 76 km2, within a study landscape of 261 km2. Orangutan nest count data were fitted to models accounting for variation in land use, above-ground carbon density (ACD, a surrogate for forest quality), strangler fig density, and elevation (between 117 and 675 m). Orangutan nest counts were significantly higher in all land uses possessing natural forest cover, regardless of degradation status, than in monoculture plantations. Within these natural forests, nest counts increased with higher ACD and strangler fig density, but not with elevation. In logged forest (ACD 14–150 Mg ha−1), strangler fig density had a significant, positive relationship with orangutan nest counts, but this relationship disappeared in a forest with higher carbon content (ACD 150–209 Mg ha−1). Based on an area-to-area comparison, orangutan nest counts from ground transects were higher than from counts derived from aerial surveys, but this did not constitute a statistically significant difference. Although the difference in nest counts was not significantly different, this analysis indicates that both methods under-sample the total number of nests present within a given area. Aerial surveys are, therefore, a useful method for assessing the orangutan habitat use over large areas. However, the under-estimation of nest counts by both methods suggests that a small number of ground surveys should be retained in future surveys using this technique, particularly in areas with dense understory vegetation. This study shows that even highly degraded forests may be a suitable orangutan habitat as long as strangler fig trees remain intact after areas of forest are logged. Enrichment planting of strangler figs may, therefore, be a valuable tool for orangutan conservation in these landscapes.

scholarly journals Determinants of bird assemblage composition in riparian vegetation on sugarcane farms in the Queensland Wet Tropics

2015 ◽  
Vol 21 (1) ◽  
pp. 60 ◽  
Author(s):  
Anita F. Keir ◽  
Richard G. Pearson ◽  
Robert A. Congdon
Keyword(s):  
Riparian Vegetation ◽  
Wildlife Conservation ◽  
Agricultural Landscape ◽  
Riparian Zone ◽  
Riparian Forest ◽  
Agricultural Landscapes ◽  
Generalist Species ◽  
Assemblage Composition ◽  
Bird Assemblages ◽  
Wet Tropics

Remnant habitat patches in agricultural landscapes can contribute substantially to wildlife conservation. Understanding the main habitat variables that influence wildlife is important if these remnants are to be appropriately managed. We investigated relationships between the bird assemblages and characteristics of remnant riparian forest at 27 sites among sugarcane fields in the Queensland Wet Tropics bioregion. Sites within the remnant riparian zone had distinctly different bird assemblages from those of the forest, but provided habitat for many forest and generalist species. Width of the riparian vegetation and distance from source forest were the most important factors in explaining the bird assemblages in these remnant ribbons of vegetation. Gradual changes in assemblage composition occurred with increasing distance from source forest, with species of rainforest and dense vegetation being replaced by species of more open habitats, although increasing distance was confounded by decreasing riparian width. Species richness increased with width of the riparian zone, with high richness at the wide sites due to a mixture of open-habitat species typical of narrower sites and rainforest species typical of sites within intact forest, as a result of the greater similarity in vegetation characteristics between wide sites and the forest proper. The results demonstrate the habitat value for birds of remnant riparian vegetation in an agricultural landscape, supporting edge and open vegetation species with even narrow widths, but requiring substantial width (>90 m) to support specialists of the closed forest, the dominant original vegetation of the area.

scholarly journals Environmental determinants of haemosporidian parasite prevalence in a declining population of Tree swallows

Parasitology ◽  
2017 ◽  
Vol 145 (7) ◽  
pp. 961-970 ◽  
Author(s):  
Audrey Turcotte ◽  
Marc Bélisle ◽  
Fanie Pelletier ◽  
Dany Garant
Keyword(s):  
Forest Cover ◽  
Agricultural Landscape ◽  
Parasite Prevalence ◽  
Landscape Composition ◽  
Breeding Period ◽  
Tree Swallows ◽  
Environmental Determinants ◽  
Negative Effects ◽  
Haemosporidian Parasite ◽  
Haemosporidian Parasites

AbstractThe prevalence of vector-borne parasites such as haemosporidian species is influenced by several environmental factors. While the negative effects of parasitism on hosts are well documented, these can also be amplified by interactions with environmental stressors, many of which are anthropogenic. Yet, we know little about the possible effects of anthropogenic perturbations on parasite prevalence. The goals of this study were to assess the prevalence and environmental determinants of haemosporidian parasites in a declining population of Tree swallows (Tachycineta bicolor) living in an agricultural landscape in southern Québec, Canada. Overall, a low prevalence and a moderate lineage diversity were identified in both adults and nestlings, confirming that transmission can occur during the breeding period. Anthropic areas, extensive cultures (hayfields and pastures) and forest cover within 500 km of nest boxes, as well as daily temperature fluctuations, were all related to infection by haemosporidian parasites. These findings suggest that anthropogenic alterations of landscape composition can modulate the prevalence of haemosporidian parasites in Tree swallows. Our results represent a baseline for future comparative studies assessing haemosporidian parasite prevalence in human-modified landscapes.

scholarly journals The Assessment of the Tourism Potential of the Tagus International Nature Reserve Landscapes Using Methods Based on the Opinion of the Demand

Land ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 68
Author(s):  
Dora Isabel Rodrigues Ferreira ◽  
José-Manuel Sánchez-Martín
Keyword(s):  
Agricultural Landscape ◽  
Nature Reserve ◽  
Pairwise Comparison ◽  
Agricultural Landscapes ◽  
Agricultural Activity ◽  
Aesthetic Value ◽  
Analytic Hierarchy ◽  
Natural Protected Areas ◽  
Double Approach ◽  
Tourism Potential

There are different methodologies to assess landscape preferences, however there is no consensual methodology that can be replicated to identify their tourism potential. Recent studies have focused on agricultural landscape preferences due to their cultural characteristics. Although agricultural activity conflicts with the management models of natural protected areas, traditional models and sustainable practices reveal opportunities to boost tourism in this area, both for their aesthetic value, and for the opportunity to preserve biodiversity and maintain “lively landscapes”. The present study focuses on a double approach to collect data to measure the preferences for landscape typologies to realize outdoor/recreative activities in Tagus International Nature Reserve (TINR), among them, agricultural landscapes, such as the agro-silvopastural system “Dehesa/Montado” or olive grove. The preference of the landscapes were evaluated through photographs with pairwise comparison and without photographs observation, in which 174 respondents were consulted with. The different methodologies applied allowed for the extraction of different results, which led to the assumption that in fact there is no single methodology to assess preferences. However, the application of the analytic hierarchy process (AHP) methodology with photographical pairwise comparison allowed for the extraction of more robust results when considering attractions with tourism typologies, revealing that “Cultural tourism/Rural mixed” and “Agritourism” were the most valued. This information is pertinent to support TINR managers and local tourism promoters to plan and structure products and services based on button-up methodologies.

scholarly journals Methods of Landscape Valorization and Possibilities of Its Application in Hunting Area Categorisation

2020 ◽  
Author(s):  
Szewczyk Grzegorz ◽  
Krzysztof Lipka ◽  
Piotr Wężyk ◽  
Karolina Zięba-Kulawik ◽  
Monika Winczek
Keyword(s):  
Natural Environment ◽  
Functional Role ◽  
Large Scale ◽  
Forest Cover ◽  
Agricultural Landscape ◽  
Environmental Changes ◽  
Environmental Values ◽  
Small Game ◽  
Forest Habitats

As a result of environmental changes, assessment indexes for the agricultural landscape have been changing dramatically. Being at the interface of human activity and the natural environment, hunting is particularly sensitive to environmental changes, such as increasing deforestation or large-scale farming. The classical categorisation of hunting grounds takes into account the area, forest cover, number of forest complexes, fertility of forest habitats, lack of continuity of areas potentially favourable to wild animals. Landscape assessment methods used in architecture often better reflect the actual breeding and hunting value of a given area, especially in relation to fields and forests. The forest-field mosaic, large spatial fragmentation as well as interweaving of natural environment elements with buildings do not have to be the factors that limit the numbers of small game. Identification of the constituents of architectural-landscape interiors: content and significance assessment, determination of the functional role or assessment based on the general environmental values being represented take into account factors important for the existence of game, in particular small game.

scholarly journals Canopy gap edge determination and the importance of gap edges for plant diversity

Web Ecology ◽  
2002 ◽  
Vol 3 (1) ◽  
pp. 1-5 ◽  
Author(s):  
D. Salvador-Van Eysenrode ◽  
F. Kockelbergh ◽  
J. Bogaert ◽  
I. Impens ◽  
P. Van Hecke
Keyword(s):  
Fagus Sylvatica ◽  
Plant Diversity ◽  
Forest Cover ◽  
Beech Forest ◽  
Canopy Gaps ◽  
Canopy Gap ◽  
Structural Elements ◽  
Forest Patch ◽  
Young Forest ◽  
Maintenance Of Diversity

Abstract. Canopy gaps, i.e. openings in the forest cover caused by the fall of structural elements, are considered to be important for the maintenance of diversity and for the forest cycle. A gap can be considered as a young forest patch in the forest matrix, composed of interior surrounded by an edge, both enclosed by a perimeter. Much of the attention has been focused on the gap interior. However, at gap edges the spectrum of regeneration opportunities for plants may be larger than in the interior. Although definitions of gap are still discussed, any definition can describe it in an acceptable way, if justified, but defining edges is complicated and appropriate descriptors should be used. A method to determine gap interior and edge, using light as a descriptor, is presented with an example of gaps from a beech forest (Fagus sylvatica) in Belgium. Also, the relevance and implications of gap edges for plant diversity and calculation of forest turnover is discussed.

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