1,720,960 research outputs found
Are they even there? How agri-environment schemes investments reach their target species in Dutch dairy-farmland, the case of meadow birds
Full text linkAgri-environmental schemes (AES) implemented by farmer collectives for meadow bird protection in The Netherlands create complex landscape mosaics due to the variability of options and combinations farmers use. We propose a method to simplify this complexity, using the number of meadow birds potentially benefiting as the measure of success, and evaluate how AES combinations affect management success as a function of monetary investments. Between 2016 and 2022, we conducted field surveys to measure the density and distribution of Black-tailed Godwits across three land-use types: AES, site-protected areas, and intensive agriculture. AES fields were categorized into nest protection, inundation, delayed mowing, and herb-rich grasslands. We analysed the relationship between these managements, the area they cover, and godwit numbers, while also examining land area and subsidies. Intensive agriculture covered 74.3 % of the area but hosted only 23.2 % of the godwit population at low densities (0.063 godwits/ha). In contrast, protected areas (6.2 % of the area) and AES fields (19.5 %) supported 24.7 % and 52.1 % of the population at higher densities (0.48 and 0.46 godwits/ha, respectively). Among AES types, delayed mowing and herb-rich grasslands showed the highest godwit densities (0.66 and 1.25 godwits/ha, respectively) covering smaller areas (6 % and 1.1 %). These AES types pay the highest subsidies, while nest protection, covering 10.5 % of the area with lower godwit densities, pays the lowest. Although AES fields hosted about half of the godwit population, area-wise the focus remained on nest protection, and with intensive agriculture dominated the landscape. This may limit effectiveness at a population level, calling for re-evaluating conservation priorities and funding.EEA BarilocheFil: Barba-Escoto, Luis. University of Groningen. Groningen Institute for Evolutionary Life Science. Conservation Ecology Group; Países BajosFil: Barba-Escoto, Luis. University of Groningen. Faculties of Science & Engineering and Campus Fryslân. Centre for Global Ecological Change. BirdEyes; Países BajosFil: Howison, Ruth Alison. University of Groningen. Groningen Institute for Evolutionary Life Science. Conservation Ecology Group; Países BajosFil: Howison, Ruth Alison. University of Groningen. Campus Fryslân. Knowledge Infrastructures Department; Países BajosFil: Howison, Ruth Alison. University of Groningen. Faculties of Science & Engineering and Campus Fryslân. Centre for Global Ecological Change. BirdEyes; Países BajosFil: Fokkema, Rienk W. University of Groningen. Groningen Institute for Evolutionary Life Science. Conservation Ecology Group; Países BajosFil: Fokkema, Rienk W. University of Groningen. Faculties of Science & Engineering and Campus Fryslân. Centre for Global Ecological Change. BirdEyes; Países BajosFil: Duriaux-Chavarría, Jean-Yves. University of Groningen. Groningen Institute for Evolutionary Life Science. Conservation Ecology Group; Países BajosFil: Stessens, Marie. University of Groningen. Groningen Institute for Evolutionary Life Science. Conservation Ecology Group; Países BajosFil: Stessens, Marie. University of Groningen. Faculties of Science & Engineering and Campus Fryslân. Centre for Global Ecological Change. BirdEyes; Países BajosFil: Velde, Egbert van der. University of Groningen. Groningen Institute for Evolutionary Life Science. Conservation Ecology Group; Países BajosFil: Velde, Egbert van der. University of Groningen. Faculties of Science & Engineering and Campus Fryslân. Centre for Global Ecological Change. BirdEyes; Países BajosFil: Hooijmeijer, Jos C.E.W. University of Groningen. Groningen Institute for Evolutionary Life Science. Conservation Ecology Group; Países BajosFil: Hooijmeijer, Jos C.E.W. University of Groningen. Faculties of Science & Engineering and Campus Fryslân. Centre for Global Ecological Change. BirdEyes; Países BajosFil: Piersma, Theunis. University of Groningen. Groningen Institute for Evolutionary Life Science. Conservation Ecology Group; Países BajosFil: Piersma, Theunis. NIOZ Royal Netherlands Institute for Sea Research. Department of Coastal Systems; Países BajosFil: Piersma, Theunis. University of Groningen. Faculties of Science & Engineering and Campus Fryslân. Centre for Global Ecological Change. BirdEyes; Países BajosFil: Tittonell, Pablo Adrian. University of Groningen. Groningen Institute for Evolutionary Life Science. Conservation Ecology Group; Países BajosFil: Tittonell, Pablo Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Tittonell, Pablo Adrian. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina
The battle between bioturbation and biocompaction:Biotically driven vegetation mosaics
No full textGrazing ecosystems ranging from the arctic tundra to tropical savannas are often characterized by small-scale mosaics of herbivore-preferred and herbivore-avoided patches, promoting their biodiversity and resilience. The three leading explanations for bistable patchiness in grazed ecosystems are: i) herbivore-driven nutrient cycling, ii) plant growth-water infiltration feedback under aridity, and iii) irreversible local herbivore-induced abiotic stress (topsoil erosion, salinity). However, these insufficiently explain the high temporal patch dynamics and wide-ranging distribution of grazing mosaics across productive habitats. Here we propose and experimentally test a fourth possibility where alternating patches are governed by the interplay of two important biotic processes: bioturbation by soil fauna that locally ameliorates soil conditions, promoting tall plant communities, alternating with biocompaction by large herbivores that locally impairs soil conditions, and promotes lawn communities. This study provides novel and important insights into the mechanisms whereby the aggregation and activities of organisms promote their own resources
The battle between bioturbation and biocompaction:Biotically driven vegetation mosaics
Full text linkGrazing ecosystems ranging from the arctic tundra to tropical savannas are often characterized by small-scale mosaics of herbivore-preferred and herbivore-avoided patches, promoting their biodiversity and resilience. The three leading explanations for bistable patchiness in grazed ecosystems are: i) herbivore-driven nutrient cycling, ii) plant growth-water infiltration feedback under aridity, and iii) irreversible local herbivore-induced abiotic stress (topsoil erosion, salinity). However, these insufficiently explain the high temporal patch dynamics and wide-ranging distribution of grazing mosaics across productive habitats. Here we propose and experimentally test a fourth possibility where alternating patches are governed by the interplay of two important biotic processes: bioturbation by soil fauna that locally ameliorates soil conditions, promoting tall plant communities, alternating with biocompaction by large herbivores that locally impairs soil conditions, and promotes lawn communities. This study provides novel and important insights into the mechanisms whereby the aggregation and activities of organisms promote their own resources
The battle between bioturbation and biocompaction:Biotically driven vegetation mosaics
Full text linkGrazing ecosystems ranging from the arctic tundra to tropical savannas are often characterized by small-scale mosaics of herbivore-preferred and herbivore-avoided patches, promoting their biodiversity and resilience. The three leading explanations for bistable patchiness in grazed ecosystems are: i) herbivore-driven nutrient cycling, ii) plant growth-water infiltration feedback under aridity, and iii) irreversible local herbivore-induced abiotic stress (topsoil erosion, salinity). However, these insufficiently explain the high temporal patch dynamics and wide-ranging distribution of grazing mosaics across productive habitats. Here we propose and experimentally test a fourth possibility where alternating patches are governed by the interplay of two important biotic processes: bioturbation by soil fauna that locally ameliorates soil conditions, promoting tall plant communities, alternating with biocompaction by large herbivores that locally impairs soil conditions, and promotes lawn communities. This study provides novel and important insights into the mechanisms whereby the aggregation and activities of organisms promote their own resources
Food preferences and feeding interactions among browsers and the effect of an exotic invasive weed Chromolaena odorata on the endangered black rhino (Diceros bicornis), in an African savanna.
Full text linkThesis (M.Sc.)-University of KwaZulu-Natal, 2009.Biodiversity changes, often resulting from climate change, land transformation, and the
transportation of organisms across geographical barriers are among the most important human
induced global changes. To optimize the spatial allocation of conservation efforts, and how to
best protect indigenous species, requires an understanding of the principal determinants that
structure ecological communities and ecosystems. We studied community-level interaction
among a diverse assemblage of specialist and generalist browsers in an African savanna.
Hluhluwe-iMfolozi Park (HiP), South Africa, hosts a complete assemblage of vertebrate species
across all trophic levels and contains a diverse guild of large browsers. Using species abundance
distributions (SADs) we graphically illustrate the diversity and abundance of woody species that
comprise six structural habitat types within HiP. We calculated the Shannon-Wiener index and
Pianka’s niche overlap to characterise the utilization of forage across habitat types among
different browser groups. By using individual plant traits we investigated mechanisms of
resource partitioning. We specifically investigated the effect of the temporal expansion of an
exotic invasive plant (Chromolaena odorata) on the critically endangered black rhino using GIS
and statistical analyses. We found that lower lying habitat types were important forage resources
for browser species and individual plant traits that are highly correlated with digestibility
strongly predicted browser preference. Black rhino used different strategic and metabolic
mechanisms to successfully compete within the same forage height range of other, smaller,
browsers. C. odorata has negatively impacted forage species utilization and has led to a spatial
reorganization of the population of black rhino. This may partly explain the recent decline in the
population. The principles within metapopulation management can be used to successfully
conserve endangered species. High diversity of browse across three dimensions (diversity,
abundance and maximum height) relative to area facilitates a high diversity and abundance of
different browsing herbivores. Therefore the spatial configurations of resources ranging from
topological attributes to the individual plant traits are essential to maintaining viable populations
of many co-occurring species within conservation areas of limited extent
The battle between bioturbation and biocompaction:Biotically driven vegetation mosaics
Full text linkGrazing ecosystems ranging from the arctic tundra to tropical savannas are often characterized by small-scale mosaics of herbivore-preferred and herbivore-avoided patches, promoting their biodiversity and resilience. The three leading explanations for bistable patchiness in grazed ecosystems are: i) herbivore-driven nutrient cycling, ii) plant growth-water infiltration feedback under aridity, and iii) irreversible local herbivore-induced abiotic stress (topsoil erosion, salinity). However, these insufficiently explain the high temporal patch dynamics and wide-ranging distribution of grazing mosaics across productive habitats. Here we propose and experimentally test a fourth possibility where alternating patches are governed by the interplay of two important biotic processes: bioturbation by soil fauna that locally ameliorates soil conditions, promoting tall plant communities, alternating with biocompaction by large herbivores that locally impairs soil conditions, and promotes lawn communities. This study provides novel and important insights into the mechanisms whereby the aggregation and activities of organisms promote their own resources
The battle between bioturbation and biocompaction:Biotically driven vegetation mosaics
Full text linkGrazing ecosystems ranging from the arctic tundra to tropical savannas are often characterized by small-scale mosaics of herbivore-preferred and herbivore-avoided patches, promoting their biodiversity and resilience. The three leading explanations for bistable patchiness in grazed ecosystems are: i) herbivore-driven nutrient cycling, ii) plant growth-water infiltration feedback under aridity, and iii) irreversible local herbivore-induced abiotic stress (topsoil erosion, salinity). However, these insufficiently explain the high temporal patch dynamics and wide-ranging distribution of grazing mosaics across productive habitats. Here we propose and experimentally test a fourth possibility where alternating patches are governed by the interplay of two important biotic processes: bioturbation by soil fauna that locally ameliorates soil conditions, promoting tall plant communities, alternating with biocompaction by large herbivores that locally impairs soil conditions, and promotes lawn communities. This study provides novel and important insights into the mechanisms whereby the aggregation and activities of organisms promote their own resources
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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