The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Lorenzo Marini - One of the best experts on this subject based on the ideXlab platform.
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high mobility reduces beta diversity among Orthopteran communities implications for conservation
Insect Conservation and Diversity, 2012Co-Authors: Lorenzo Marini, Erik Ockinger, Andrea Battisti, Riccardo BommarcoAbstract:. 1. The analysis of β-diversity, i.e. species turnover, across space is central to a wide array of ecological and evolutionary topics, also providing critical information to conservation planning. Although dispersal limitation has been demonstrated to play an important role in determining insect community structure, very little research has been done to test whether mobility might affect the diversity distribution of species across multiple spatial scales. 2. We considered Orthopterans (Ensifera and Caelifera) inhabiting hay meadows to test whether species mobility modifies β-diversity patterns across three nested spatial scales (1-m2 plots within meadow, 1000-m2 meadows within landscape, and 19.6-km2 landscapes within a region) and along a gradient of management intensity. 3. Orthopteran community composition varied most significantly over broader spatial scales. Larger proportion of regional γ-diversity was mainly composed of β-diversity at the landscape scale, whereas this proportion was smaller at the plot and meadow scale. 4. Mobility, but not management, strongly modified β-diversity patterns. Sedentary species contributed to a greater proportion of β-diversity across all the investigated scales compared with mobile species. 5. Measures currently included in most agri-environment schemes have only focused on the extensive management at the field scale. Our results imply that Orthopteran diversity would benefit from maintaining extensively managed meadows scattered throughout the whole region, as the loss of species-rich isolated grassland patches due to abandonment or eutrophication might cause severe reductions of the regional species pool. Increasing connectivity might be also considered as a complementary measure to increase species occupancy and population persistence, particularly for sedentary species.
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High mobility reduces beta-diversity among Orthopteran communities – implications for conservation
Insect Conservation and Diversity, 2011Co-Authors: Lorenzo Marini, Erik Ockinger, Andrea Battisti, Riccardo BommarcoAbstract:. 1. The analysis of β-diversity, i.e. species turnover, across space is central to a wide array of ecological and evolutionary topics, also providing critical information to conservation planning. Although dispersal limitation has been demonstrated to play an important role in determining insect community structure, very little research has been done to test whether mobility might affect the diversity distribution of species across multiple spatial scales. 2. We considered Orthopterans (Ensifera and Caelifera) inhabiting hay meadows to test whether species mobility modifies β-diversity patterns across three nested spatial scales (1-m2 plots within meadow, 1000-m2 meadows within landscape, and 19.6-km2 landscapes within a region) and along a gradient of management intensity. 3. Orthopteran community composition varied most significantly over broader spatial scales. Larger proportion of regional γ-diversity was mainly composed of β-diversity at the landscape scale, whereas this proportion was smaller at the plot and meadow scale. 4. Mobility, but not management, strongly modified β-diversity patterns. Sedentary species contributed to a greater proportion of β-diversity across all the investigated scales compared with mobile species. 5. Measures currently included in most agri-environment schemes have only focused on the extensive management at the field scale. Our results imply that Orthopteran diversity would benefit from maintaining extensively managed meadows scattered throughout the whole region, as the loss of species-rich isolated grassland patches due to abandonment or eutrophication might cause severe reductions of the regional species pool. Increasing connectivity might be also considered as a complementary measure to increase species occupancy and population persistence, particularly for sedentary species.
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disentangling effects of habitat diversity and area on Orthopteran species with contrasting mobility
Biological Conservation, 2010Co-Authors: Lorenzo Marini, Paolo Fontana, Riccardo Bommarco, Andrea BattistiAbstract:Loss of semi-natural grasslands and reduction of habitat diversity are considered major potential threats to arthropod diversity in agricultural landscapes. The main aim of this study was to investigate how area and habitat diversity, mediated by shrub encroachment after grassland abandonment, affect species richness of Orthopterans in island-like grasslands, and how contrasting mobility might alter species richness response to both factors. We selected 35 isolated patches in landscapes dominated by arable land (durum wheat) in order to obtain two statistically uncorrelated gradients: (i) one in habitat area ranging from 0.2 to 55 ha and (ii) one in habitat diversity ranging from patches dominated by one habitat (either open grasslands or shrublands) to patches with a mosaic of different habitats. Habitat loss due to land-use conversion into arable fields was associated with a substantial loss of species with a positive species–area relationship (SAR), with sedentary species having a steeper and stronger SAR than mobile species. Halting habitat loss is, therefore, needed to avoid further species extinctions. Shrub encroachment, triggered by abandonment, presented a hump-shaped relationship with habitat diversity. An increase in habitat diversity enhanced species richness irrespective of patch area and mobility. Maintaining or enhancing habitat diversity, by cutting or burning small sectors and by reintroducing extensive sheep grazing into abandoned grassland, are suggested as complementary strategies to mitigate further decline of Orthopteran diversity in the remnant patches. This would be equally important in both small and large patches.
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response of Orthopteran diversity to abandonment of semi natural meadows
Agriculture Ecosystems & Environment, 2009Co-Authors: Lorenzo Marini, Paolo Fontana, Andrea Battisti, Kevin J GastonAbstract:The response of Orthopteran communities to abandonment of extensively managed hay meadows was investigated in an Alpine region. Fifty-five sites in four different successional stages were sampled: (i) mown meadows, (ii) young abandoned meadows, (iii) old abandoned meadows, and (iv) young forests. Mown meadows and young abandoned meadows (3–5 years since the last cut) had the highest, young forests the lowest mean number of Orthopteran species. The change in vegetation structure and the shading by woody plants are considered the most important drivers determining the Orthopteran diversity response to abandonment. Well-targeted agri-environment schemes are needed to maintain extensive semi-natural hay meadows with the provision of compensation payments to support transitional stages (young and old abandoned meadows). A mowing regime with a supra-annual cycle (e.g. 3–5 years) could be a suitable management practice to reduce direct mortality due to mechanical mowing and to halt forest invasion.
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Effects of small-scale grassland fragmentation and frequent mowing on population density and species diversity of Orthopterans: a long-term study
Ecological Entomology, 2009Co-Authors: Brigitte Braschler, Lorenzo Marini, G. Heinrich Thommen, Bruno BaurAbstract:1. Habitat fragmentation is considered one of the major threats to invertebrate diversity in semi-natural grassland. However, the effects of habitat fragmentation through mowing on the rich insect fauna of these grasslands have not been sufficiently investigated and experiments are especially rare. 2. We studied the impact of small-scale grassland fragmentation on Orthopterans over 7 years in an experiment which allowed us to additionally investigate the effect of frequent mowing on Orthoptera communities. 3. Overall, Orthoptera density and species richness increased over time. This was likely a result of increased small-scale habitat heterogeneity and the provision of a short-turf habitat suitable for xerophilous species. The fragmentation affected Orthopteran density and species composition but not species richness whose response lagged behind the changes in abundance. 4. Responses differed between suborders. Ensifera density was higher in fragment than in control plots. Caelifera density did not differ between fragment and control plots. The mown matrix was an unsuitable habitat for most of the species, particularly within the Ensifera. 5. Our experiment shows that even small-scale fragmentation can affect Orthopteran communities and that the effects became more pronounced over time. As the mown matrix was unsuitable for many Ensifera species, they may go locally extinct when large areas are mown simultaneously.
A. A. Pokivailov - One of the best experts on this subject based on the ideXlab platform.
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Zoogeographic regionalization of Southwestern Tajikistan based on the Orthoptera distribution
Entomological Review, 2011Co-Authors: A. A. PokivailovAbstract:A new scheme of zoogeographic regionalization of Southwestern Tajikistan based on the data on the Orthoptera distribution is proposed. The main foci of species endemism are distinguished. The species diversity is higher in the plain (up to 800 m above see level) zoogeographic entities than in the mountain entities of comparable size.
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composition and dynamics of communities of Orthopteran insects orthoptera in southwestern tajikistan ii hillside communities
Contemporary Problems of Ecology, 2008Co-Authors: A. A. PokivailovAbstract:The formation of Orthopteran communities in the mountains of southwestern Tajikistan is described, with their seasonal dynamics characterized on the basis of counts. It is shown that the dominance structure changes with altitude. The valleys and slopes of different altitudinal belts play an important role in the formation of communities of Orthopteran insects.
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Long-term dynamics of Orthopteran assemblages (orthoptera) of the Hissar Valley (Tajikistan)
Entomological Review, 2007Co-Authors: A. A. PokivailovAbstract:Results of investigation of the species composition and population density of the Orthopteran assemblages, performed in the Hissar Valley in 1935 and 1989 are discussed. The increased anthropogenic press resulted in the drastic changes in the assemblages during 50 years. Two species dominating in the past, Calliptamus italicus (L.) and Dociostaurus maroccanus (Thunb.), are indicators of the integrity of original assemblages (and entire ecosystems of Hissar Valley, which are now completely destroyed) or of their insignificant transformation. The recent mesomorphic assemblages are dominated by Oxya fuscovittata (Marsch.), Duroniella gracilis Uv., Chorthippus biguttulus (L.), Aiolopus thalassinus (Fabr.), and xeromorphic communities, by Calliptamus barbarus (Costa), Dociostaurus tartarus (Stshelk.), Oedipoda miniata (Pall.), and Acrotylus insubricus (Scop.). The predominance and wide distribution of these species points to a significant transformation of ecosystems and destabilization of the environment in the Hissar Valley.
Szabolcs Lengyel - One of the best experts on this subject based on the ideXlab platform.
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early changes of Orthopteran assemblages after grassland restoration a comparison of space for time substitution versus repeated measures monitoring
Biodiversity and Conservation, 2013Co-Authors: Istvan Racz, Eszter Deri, Mate Kisfali, Zoltan Batiz, Katalin Varga, Gyula Szabo, Szabolcs LengyelAbstract:Although grasslands harbour significant biodiversity and their restoration is common in biodiversity conservation, we know very little about how such interventions influence arthropod groups. Here we compared Orthopteran assemblages in croplands, natural grasslands and one to four-year-old grasslands restored in a large-scale programme in Hortobagy National Park (East Hungary). We sampled Orthopterans by standardized sweep-netting both in a repeated measures design from Year 0 (croplands) to 4 and in a space-for-time substitution (chronosequence) design in 2009. Species richness, abundance and Shannon diversity of Orthopterans decreased in Year 1 following restoration, but increased afterwards. By Year 4, species richness doubled and abundance increased almost ten-fold in restored grasslands compared to croplands. Species composition diversified compared to croplands and progressed towards natural grasslands. Local restoration conditions (last crop, seed mixture) and landscape configuration (proportion of natural grasslands) did not influence the above patterns in either study design, whereas time since restoration affected almost all community variables. We found that ubiquitous generalist species were the first to appear in restored grasslands and that species characteristic to the target natural grasslands colonised gradually in later years. The qualitative and quantitative properties of the Orthopteran assemblages in restored fields did not yet reach those of natural grasslands, therefore, our study suggests that the full regeneration of the Orthopteran assemblages takes more than four years. We also concluded that the repeated-measures design was more sensitive to subtle changes and was thus more effective than the chronosequence design at detecting post-restoration changes in Orthopteran assemblages.
Andrea Battisti - One of the best experts on this subject based on the ideXlab platform.
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high mobility reduces beta diversity among Orthopteran communities implications for conservation
Insect Conservation and Diversity, 2012Co-Authors: Lorenzo Marini, Erik Ockinger, Andrea Battisti, Riccardo BommarcoAbstract:. 1. The analysis of β-diversity, i.e. species turnover, across space is central to a wide array of ecological and evolutionary topics, also providing critical information to conservation planning. Although dispersal limitation has been demonstrated to play an important role in determining insect community structure, very little research has been done to test whether mobility might affect the diversity distribution of species across multiple spatial scales. 2. We considered Orthopterans (Ensifera and Caelifera) inhabiting hay meadows to test whether species mobility modifies β-diversity patterns across three nested spatial scales (1-m2 plots within meadow, 1000-m2 meadows within landscape, and 19.6-km2 landscapes within a region) and along a gradient of management intensity. 3. Orthopteran community composition varied most significantly over broader spatial scales. Larger proportion of regional γ-diversity was mainly composed of β-diversity at the landscape scale, whereas this proportion was smaller at the plot and meadow scale. 4. Mobility, but not management, strongly modified β-diversity patterns. Sedentary species contributed to a greater proportion of β-diversity across all the investigated scales compared with mobile species. 5. Measures currently included in most agri-environment schemes have only focused on the extensive management at the field scale. Our results imply that Orthopteran diversity would benefit from maintaining extensively managed meadows scattered throughout the whole region, as the loss of species-rich isolated grassland patches due to abandonment or eutrophication might cause severe reductions of the regional species pool. Increasing connectivity might be also considered as a complementary measure to increase species occupancy and population persistence, particularly for sedentary species.
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High mobility reduces beta-diversity among Orthopteran communities – implications for conservation
Insect Conservation and Diversity, 2011Co-Authors: Lorenzo Marini, Erik Ockinger, Andrea Battisti, Riccardo BommarcoAbstract:. 1. The analysis of β-diversity, i.e. species turnover, across space is central to a wide array of ecological and evolutionary topics, also providing critical information to conservation planning. Although dispersal limitation has been demonstrated to play an important role in determining insect community structure, very little research has been done to test whether mobility might affect the diversity distribution of species across multiple spatial scales. 2. We considered Orthopterans (Ensifera and Caelifera) inhabiting hay meadows to test whether species mobility modifies β-diversity patterns across three nested spatial scales (1-m2 plots within meadow, 1000-m2 meadows within landscape, and 19.6-km2 landscapes within a region) and along a gradient of management intensity. 3. Orthopteran community composition varied most significantly over broader spatial scales. Larger proportion of regional γ-diversity was mainly composed of β-diversity at the landscape scale, whereas this proportion was smaller at the plot and meadow scale. 4. Mobility, but not management, strongly modified β-diversity patterns. Sedentary species contributed to a greater proportion of β-diversity across all the investigated scales compared with mobile species. 5. Measures currently included in most agri-environment schemes have only focused on the extensive management at the field scale. Our results imply that Orthopteran diversity would benefit from maintaining extensively managed meadows scattered throughout the whole region, as the loss of species-rich isolated grassland patches due to abandonment or eutrophication might cause severe reductions of the regional species pool. Increasing connectivity might be also considered as a complementary measure to increase species occupancy and population persistence, particularly for sedentary species.
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disentangling effects of habitat diversity and area on Orthopteran species with contrasting mobility
Biological Conservation, 2010Co-Authors: Lorenzo Marini, Paolo Fontana, Riccardo Bommarco, Andrea BattistiAbstract:Loss of semi-natural grasslands and reduction of habitat diversity are considered major potential threats to arthropod diversity in agricultural landscapes. The main aim of this study was to investigate how area and habitat diversity, mediated by shrub encroachment after grassland abandonment, affect species richness of Orthopterans in island-like grasslands, and how contrasting mobility might alter species richness response to both factors. We selected 35 isolated patches in landscapes dominated by arable land (durum wheat) in order to obtain two statistically uncorrelated gradients: (i) one in habitat area ranging from 0.2 to 55 ha and (ii) one in habitat diversity ranging from patches dominated by one habitat (either open grasslands or shrublands) to patches with a mosaic of different habitats. Habitat loss due to land-use conversion into arable fields was associated with a substantial loss of species with a positive species–area relationship (SAR), with sedentary species having a steeper and stronger SAR than mobile species. Halting habitat loss is, therefore, needed to avoid further species extinctions. Shrub encroachment, triggered by abandonment, presented a hump-shaped relationship with habitat diversity. An increase in habitat diversity enhanced species richness irrespective of patch area and mobility. Maintaining or enhancing habitat diversity, by cutting or burning small sectors and by reintroducing extensive sheep grazing into abandoned grassland, are suggested as complementary strategies to mitigate further decline of Orthopteran diversity in the remnant patches. This would be equally important in both small and large patches.
-
response of Orthopteran diversity to abandonment of semi natural meadows
Agriculture Ecosystems & Environment, 2009Co-Authors: Lorenzo Marini, Paolo Fontana, Andrea Battisti, Kevin J GastonAbstract:The response of Orthopteran communities to abandonment of extensively managed hay meadows was investigated in an Alpine region. Fifty-five sites in four different successional stages were sampled: (i) mown meadows, (ii) young abandoned meadows, (iii) old abandoned meadows, and (iv) young forests. Mown meadows and young abandoned meadows (3–5 years since the last cut) had the highest, young forests the lowest mean number of Orthopteran species. The change in vegetation structure and the shading by woody plants are considered the most important drivers determining the Orthopteran diversity response to abandonment. Well-targeted agri-environment schemes are needed to maintain extensive semi-natural hay meadows with the provision of compensation payments to support transitional stages (young and old abandoned meadows). A mowing regime with a supra-annual cycle (e.g. 3–5 years) could be a suitable management practice to reduce direct mortality due to mechanical mowing and to halt forest invasion.
Francois Gillet - One of the best experts on this subject based on the ideXlab platform.
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contrasting processes drive alpha and beta taxonomic functional and phylogenetic diversity of Orthopteran communities in grasslands
Agriculture Ecosystems & Environment, 2017Co-Authors: Bertrand Fournier, Arnaud Mouly, Francois Gillet, Marco MorettiAbstract:Abstract Taxonomic, functional and phylogenetic diversities can respond differently to biotic and abiotic filters. However, biodiversity management tends to focus on a single index, generally taxonomic diversity, assuming a strong positive correlation among biodiversity components across scales. This can result in a mismanagement of functional and phylogenetic diversities with negative consequences for ecosystem functioning and long-term maintenance of services. Understanding the relationships among biodiversity components, how they change across scales and which their main drivers are can lead to more sustainable management of biodiversity and its associated ecosystem services and functions. We used an integrative approach of biodiversity where we investigated alpha and beta taxonomic (TD), functional (FD) and phylogenetic (PD) diversity of Orthopteran communities as well as species and functional traits composition and their associated drivers at the local and landscape scales in permanent mesic grasslands of the French Jura Mountains. We assessed whether Orthopteran TD, FD and PD were positively correlated. We also determined the drivers of TD, FD and PD and their changes across scales and among indices using data related to soil, agricultural practices, elevation, and biotic interactions with plants. Our results showed that (i) elevation was a strong driver of Orthopteran community trait composition, (ii) Orthopteran alpha TD, FD and PD were correlated among themselves and increased with plant species richness, and (iii) local beta diversity was not correlated with alpha diversity. Beta diversity had different drivers at local and landscape scale: it was influenced by soil chemistry and texture at the local scale and increased with the difference in elevation among plots at the landscape scale. This study evidences distinct processes driving alpha and beta diversity of Orthopteran communities at both the local and landscape scales. It supports the hypothesis that less intensive agricultural practices enhance Orthopteran diversity and highlights the importance to consider beta diversity at both local and landscape scale when designing and assessing the management regimes of grassland ecosystems. Prioritizing the importance of the different biodiversity components and spatial scales constitutes an important challenge for sustainable grassland management.
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multiple assembly rules drive the co occurrence of Orthopteran and plant species in grasslands combining network functional and phylogenetic approaches
Frontiers in Plant Science, 2016Co-Authors: Bertrand Fournier, Arnaud Mouly, Francois GilletAbstract:Understanding the factors underlying the co-occurrence of multiple species remains a challenge in ecology. Biotic interactions, environmental filtering and neutral processes are among the main mechanisms evoked to explain species co-occurrence. However, they are most often studied separately or even considered as mutually exclusive. This likely hampers a more global understanding of species assembly. Here, we investigate the general hypothesis that the structure of co-occurrence networks results from multiple assembly rules and its potential implications for grassland ecosystems. We surveyed Orthopteran and plant communities in 48 permanent grasslands of the French Jura Mountains and gathered functional and phylogenetic data for all species. We constructed a network of plant and Orthopteran species co-occurrences and verified whether its structure was modular or nested. We investigated the role of all species in the structure of the network (modularity and nestedness). We also investigated the assembly rules driving the structure of the plant-Orthopteran co-occurrence network by using null models on species functional traits, phylogenetic relatedness and environmental conditions. We finally compared our results to abundance-based approaches. We found that the plant-Orthopteran co-occurrence network had a modular organization. Community assembly rules differed among modules for plants while interactions with plants best explained the distribution of Orthopterans into modules. Few species had a disproportionately high positive contribution to this modular organization and are likely to have a key importance to modulate future changes. The impact of agricultural practices was restricted to some modules (3 out of 5) suggesting that shifts in agricultural practices might not impact the entire plant-Orthopteran co-occurrence network. These findings support our hypothesis that multiple assembly rules drive the modular structure of the plant-Orthopteran network. This modular structure is likely to play a key role in the response of grassland ecosystems to future changes by limiting the impact of changes in agricultural practices such as intensification to some modules leaving species from other modules poorly impacted. The next step is to understand the importance of this modular structure for the long-term maintenance of grassland ecosystem structure and functions as well as to develop tools to integrate network structure into models to improve their capacity to predict future changes.
