scholarly journals Grassland-to-crop conversion in agricultural landscapes has lasting impact on the trait diversity of bees

2020 ◽  
Author(s):  
Gaëtane Le Provost ◽  
Isabelle Badenhausser ◽  
Cyrille Violle ◽  
Fabrice Requier ◽  
Marie D’Ottavio ◽  
...  
Keyword(s):  
Land Use ◽  
Habitat Loss ◽  
Agricultural Landscapes ◽  
Habitat Destruction ◽  
Land Use History ◽  
Pollinator Decline ◽  
Plant Trait ◽  
Trait Diversity ◽  
Bee Communities ◽  
Over Time

Abstract Context Global pollinator decline has motivated much research to understand the underlying mechanisms. Among the multiple pressures threatening pollinators, habitat loss has been suggested as a key-contributing factor. While habitat destruction is often associated with immediate negative impacts, pollinators can also exhibit delayed responses over time. Objectives We used a trait-based approach to investigate how past and current land use at both local and landscape levels impact plant and wild bee communities in grasslands through a functional lens. Methods We measured flower and bee morphological traits that mediate plant–bee trophic linkage in 66 grasslands. Using an extensive database of 20 years of land-use records, we tested the legacy effects of the landscape-level conversion of grassland to crop on flower and bee trait diversity. Results Land-use history was a strong driver of flower and bee trait diversity in grasslands. Particularly, bee trait diversity was lower in landscapes where much of the land was converted from grassland to crop long ago. Bee trait diversity was also strongly driven by plant trait diversity computed with flower traits. However, this relationship was not observed in landscapes with a long history of grassland-to-crop conversion. The effects of land-use history on bee communities were as strong as those of current land use, such as grassland or mass-flowering crop cover in the landscape. Conclusions Habitat loss that occurred long ago in agricultural landscapes alters the relationship between plants and bees over time. The retention of permanent grassland sanctuaries within intensive agricultural landscapes can offset bee decline.

scholarly journals HistMapR: Rapid digitization of historical land-use maps in R

2017 ◽  
Author(s):  
Alistair G. Auffret ◽  
Adam Kimberley ◽  
Jan Plue ◽  
Helle Skånes ◽  
Simon Jakobsson ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Service Provision ◽  
Habitat Destruction ◽  
Raster Image ◽  
Different Types ◽  
Historical Land Use ◽  
Time Periods ◽  
Over Time ◽  
Land Use Maps

Abstract1. Habitat destruction and degradation represent serious threats to biodiversity, and quantification of land-use change over time is important for understanding the consequences of these changes to organisms and ecosystem service provision.2. Comparing land use between maps from different time periods allows estimation of the magnitude of habitat change in an area. However, digitizing historical maps manually is time-consuming and analyses of change are usually carried out at small spatial extents or at low resolutions.3. We developed a method to semi-automatically digitize historical land-use maps using the R environment. We created a number of functions that use the existing raster package to classify land use according to a map’s colours, as defined by the RGB channels of the raster image. The method was tested on three different types of historical land-use map and results were compared to manual digitisations.4. Our method is fast, and agreement with manually-digitised maps of around 80-92% meets common targets for image classification. We hope that the ability to quickly classify large areas of historical land-use will promote the inclusion of land-use change into analyses of biodiversity, species distributions and ecosystem services.

scholarly journals Toward a Dualistic Growth? Population Increase and Land-Use Change in Rome, Italy

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 749
Author(s):  
Leonardo Bianchini ◽  
Gianluca Egidi ◽  
Ahmed Alhuseen ◽  
Adele Sateriano ◽  
Sirio Cividino ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Population Growth ◽  
Mediterranean Basin ◽  
Urban Expansion ◽  
Arable Land ◽  
Central Italy ◽  
Agricultural Landscapes ◽  
Population Increase ◽  
Per Capita

The spatial mismatch between population growth and settlement expansion is at the base of current models of urban growth. Empirical evidence is increasingly required to inform planning measures promoting urban containment in the context of a stable (or declining) population. In these regards, per-capita indicators of land-use change can be adopted with the aim at evaluating long-term sustainability of urbanization processes. The present study assesses spatial variations in per-capita indicators of land-use change in Rome, Central Italy, at five years (1949, 1974, 1999, 2008, and 2016) with the final objective of quantifying the mismatch between urban expansion and population growth. Originally specialized in agricultural productions, Rome’s metropolitan area is a paradigmatic example of dispersed urban expansion in the Mediterranean basin. By considering multiple land-use dynamics, per-capita indicators of landscape change delineated three distinctive waves of growth corresponding with urbanization, suburbanization, and a more mixed stage with counter-urbanization and re-urbanization impulses. By reflecting different socioeconomic contexts on a local scale, urban fabric and forests were identified as the ‘winner’ classes, expanding homogeneously over time at the expense of cropland. Agricultural landscapes experienced a more heterogeneous trend with arable land and pastures declining systematically and more fragmented land classes (e.g., vineyards and olive groves) displaying stable (or slightly increasing) trends. The continuous reduction of per-capita surface area of cropland that’s supports a reduced production base, which is now insufficient to satisfy the rising demand for fresh food at the metropolitan scale, indicates the unsustainability of the current development in Rome and more generally in the whole Mediterranean basin, a region specialized traditionally in (proximity) agricultural productions.

Importance of meteorological and land use parameters for insect diversity in agricultural landscapes

2021 ◽  
pp. 148159
Author(s):  
Jakub Horák ◽  
Patrik Rada ◽  
Ludwig Lettenmaier ◽  
Michal Andreas ◽  
Petr Bogusch ◽  
...  
Keyword(s):  
Land Use ◽  
Agricultural Landscapes ◽  
Insect Diversity

scholarly journals Analysis of spatiotemporal changes of agricultural land after the Second World War in Czechia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vít Zelinka ◽  
Johana Zacharová ◽  
Jan Skaloš
Keyword(s):  
Land Use ◽  
Agricultural Land ◽  
Population Change ◽  
Temporal Analysis ◽  
Second World War ◽  
Agricultural Landscapes ◽  
German Population ◽  
World War ◽  
Landscape Type ◽  
Second World

AbstractThe term Sudetenland refers to large regions of the former Czechoslovakia that had been dominated by Germans. German population was expelled directly after the Second World War, between 1945 and 1947. Almost three million people left large areas in less than two years. This population change led to a break in the relationship between the people and the landscape. The aim of the study is to compare the trajectories of these changes in agricultural landscapes in lower and higher altitudes, both in depopulated areas and areas with preserved populations. This study included ten sites in the region of Northern Bohemia in Czechia (18,000 ha in total). Five of these sites represent depopulated areas, and the other five areas where populations remained preserved. Changes in the landscape were assessed through a bi-temporal analysis of land use change by using aerial photograph data from time hoirzons of 2018 and 1953. Land use changes from the 1950s to the present are corroborated in the studied depopulated and preserved areas mainly by the trajectory of agricultural land to forest. The results prove that both population displacement and landscape type are important factors that affect landscape changes, especially in agricultural landscapes.

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