Biodiversité

Plusieurs études le prouvent : les événements de mortalité massive d'animaux ont augmenté en fréquence et en ampleur depuis le milieu du 20e siècle, parallèlement au changement climatique.

Recent declines of many European bird species have been linked with various environmental changes, especially land-use change and climate change. Since the intensity of these environmental changes varies among different countries, we can expect geographic variation in bird population trends. Here, we compared the population trends of bird species among neighbouring countries within central Europe (Czech Republic, Denmark, Germany, Switzerland) between 1990 and 2016 and examined trait-associations with population trends at both national and international scales. We found that Denmark had the highest proportion of declining species while Switzerland had the lowest.

Pour limiter dépression et anxiété, rien ne vaut des espaces naturels avec des espèces variées de plantes et d’oiseaux, affirme une étude allemande.

Travailler sur la préservation de la biodiversité, c’est un peu tenir le rôle principal d’"Un jour sans fin", ce film d’Harold Ramis où le protagoniste interprété par Bill Murray revit indéfiniment les mêmes scènes. Car les semaines se ressemblent étonnamment pour un biologiste : elles sont de plus en plus en plus fréquemment ponctuées par la publication d’une étude scientifique pointant l’érosion massive de la biodiversité.

La biomasse – c’est-à-dire le poids total de tous les insectes – a diminué de 67 % dans les prairies allemandes. Dans les forêts, elle a diminué d’environ 40 %.

Dans cette nouvelle étude dirigée par Sebastian Seibold et Wolfgang Weisse, tous deux professeurs d’écologie terrestre à la TUM, des données sur les insectes volants de 290 sites en Allemagne ont été analysées. La récolte de données a été réalisée entre 2008 et 2017. Les chercheurs ont notamment compté les insectes volants, ainsi que les arthropodes comme les araignées et les mille-pattes, à l’aide de filets et de pièges.

Le lièvre d’Europe est menacé d’extinction. L’agriculture intensive semble l'une des causes de l’affaiblissement de son système immunitaire. L’Institut Leibniz pour la recherche zoologique et la faune sauvage, au nord-est de Berlin, planche sur l'espèce et les moyens de la préserver.

A major limitation of current reports on insect declines is the lack of standardized, long-term, and taxonomically broad time series. Here, we demonstrate the utility of environmental DNA from archived leaf material to characterize plant-associated arthropod communities. We base our work on several multi-decadal leaf time series from tree canopies in four land use types, which were sampled as part of a long-term environmental monitoring program across Germany.

Au sommaire notamment :

Citizen science data for urban planning: Comparing different sampling schemes for modelling urban bird distribution

Aimara Planillo & al.

Species richness is positively related to mental health – A study for Germany

The neighborhood socioeconomic inequalities in urban parks in a High-density City: An environmental justice perspective

Regional planning of river protection and restoration to promote ecosystem services and nature conservation

The ongoing biodiversity crisis becomes evident in the widely observed decline in abundance and diversity of species, profound changes in community structure and shifts in the species' phenology. Insects are among the most affected groups, with documented decreases in abundance up to 76% in the last 25–30 years in some terrestrial ecosystems. Identifying the underlying drivers is a major obstacle as most ecosystems are affected by multiple stressors simultaneously and in situ measurements of environmental variables are often missing. In our study, we investigated a headwater stream belonging to the most common stream type in Germany located in a nature reserve with no major anthropogenic impact except climate change.

Une nouvelle étude, publiée dans la revue "Nature", conclut à une accélération de l'effondrement des populations d'arthropodes, dans les forêts et prairies d'Allemagne.

Les chercheurs ont analysé à la fois le nombre d'individus et leur biomasse, c'est-à-dire leur poids total. Pour ces deux indicateurs, les chiffres sont sidérants. Dans les prairies, la population d'individus capturés a chuté de 78% et leur biomasse de 67%. Dans les forêts, le déclin est respectivement de 36% et 41%.

Compared to a decade ago, today the number of insect species on many areas has decreased by about one third. This is the result of a survey of an international research team led by scientists from the Technical University of Munich (TUM). The loss of species mainly affects grasslands in the vicinity of intensively farmed land – but also applies to forests and protected areas.

Wolves (Canis lupus) are currently showing a remarkable comeback in the highly fragmented cultural landscapes of Germany. We here show that wolf numbers increased exponentially between 2000 and 2015 with an annual increase of about 36%. We demonstrate that the first territories in each newly colonized region were established over long distances from the nearest known reproducing pack on active military training areas (MTAs). We show that MTAs, rather than protected areas, served as stepping‐stones for the recolonization of Germany facilitating subsequent spreading of wolf territories in the surrounding landscape. We did not find any significant difference between MTAs and protected areas with regard to habitat. One possible reason for the importance of MTAs may be their lower anthropogenic mortality rates compared to protected and other areas. To our knowledge, this is the first documented case where MTAs facilitate the recolonization of an endangered species across large areas.