Das Futterwahlverhalten des Rehes in einem voralpinen Revier

European Journal of Wildlife Research - Von April bis Juli 1972 wurden im voralpinen Revier Grabs Ost Beobachtungen zum Futterwahlverhalten des Rehes ausgeführt. Die Rehe wurden beim Äsen...     

Preclinical insights into the gut‐skeletal muscle axis in chronic gastrointestinal diseases

Muscle wasting represents a constant pathological feature of common chronic gastrointestinal diseases, including liver cirrhosis (LC), inflammatory bowel diseases (IBD), chronic pancreatitis (CP) and pancreatic cancer (PC), and is associated with increased morbidity and mortality. Recent clinical and experimental studies point to the existence of a gut‐skeletal muscle axis that is constituted by specific gut‐derived mediators which activate pro‐ and anti‐sarcopenic signalling pathways in skeletal muscle cells. A pathophysiological link between both organs is also provided by low‐grade systemic inflammation. Animal models of LC, IBD, CP and PC represent an important resource for mechanistic and preclinical studies on disease‐associated muscle wasting. They are also required to test and validate specific anti‐sarcopenic therapies prior to clinical application. In this article, we review frequently used rodent models of muscle wasting in the context of chronic gastrointestinal diseases, survey their specific advantages and limitations and discuss possibilities for further research activities in the field. We conclude that animal models of LC‐, IBD‐ and PC‐associated sarcopenia are an essential supplement to clinical studies because they may provide additional mechanistic insights and help to identify molecular targets for therapeutic interventions in humans.     

Desert breath—How fog promotes a novel type of soil biocenosis,forming the coastal Atacama Desert’s living skin

The Atacama Desert is the driest non‐polar desert on Earth, presenting precarious conditions for biological activity. In the arid coastal belt, life is restricted to areas with fog events that cause almost daily wet–dry cycles. In such an area, we discovered a hitherto unknown and unique ground covering biocenosis dominated by lichens, fungi, and algae attached to grit‐sized (~6 mm) quartz and granitoid stones. Comparable biocenosis forming a kind of a layer on top of soil and rock surfaces in general is summarized as cryptogamic ground covers (CGC) in literature. In contrast to known CGC from arid environments to which frequent cyclic wetting events are lethal, in the Atacama Desert every fog event is answered by photosynthetic activity of the soil community and thus considered as the desert's breath. Photosynthesis of the new CGC type is activated by the lowest amount of water known for such a community worldwide thus enabling the unique biocenosis to fulfill a variety of ecosystem services. In a considerable portion of the coastal Atacama Desert, it protects the soil from sporadically occurring splash erosion and contributes to the accumulation of soil carbon and nitrogen as well as soil formation through bio‐weathering. The structure and function of the new CGC type are discussed, and we suggest the name grit–crust. We conclude that this type of CGC can be expected in all non‐polar fog deserts of the world and may resemble the cryptogam communities that shaped ancient Earth. It may thus represent a relevant player in current and ancient biogeochemical cycling.     

Telomere shortening correlates with harsh weather conditions in the bat species Myotis myotis

The relationship of telomere shortening and cellular ageing in cultured cells such as fibroblasts is straightforward: telomeres shorten with an increasing number of cell divisions until they trigger replicative senescence which prevents further mitotic cycles. But studies investigating the relationship between telomere shortening and ageing in whole organisms show contrasting results: while there is a clear decline in telomere length (TL) with chronological age in some species such as humans, no such decline is observed in others. In this issue of Molecular Ecology, Foley et al. (2020) show that experiencing harsh weather conditions correlates with longitudinal telomere shortening in the bat species Myotis myotis, whereas chronological age does not (Foley et al., 2020). Further, the authors investigated whether genetics influence TL and find a low heritability (h² = 0.01–0.06) again suggesting that environmental effects are the dominant drivers of variation in TL in this species. These are important findings as there is disagreement in the literature about the relative magnitude of genetic and environmental effects contributing to TL variation in different species. This paper investigating the impact of environmental effects makes a novel and important contribution to the literature on TL in free‐living mammals.     

Plant–Environment Interactions in the Low Arctic Torngat Mountains of Labrador

Ecosystems - The eastern Canadian Subarctic and Arctic are experiencing significant environmental change with widespread implications for the people, plants, and animals living there. In this...     

Water availability and population origin affect the expression of the tradeoff between reproduction and growth in Plantago coronopus

Investment in reproduction and growth represent a classic tradeoff with implication for life history evolution. The local environment can play a major role in the magnitude and evolutionary consequences of such a tradeoff. Here, we examined the investment in reproductive and vegetative tissue in 40 maternal half‐sib families from four different populations of the herb Plantago coronopus growing in either a dry or wet greenhouse environment. Plants originated from populations with an annual or a perennial life form, with annuals prevailing in drier habitats with greater seasonal variation in both temperature and precipitation. We found that water availability affected the expression of the tradeoff (both phenotypic and genetic) between reproduction and growth, being most accentuated under dry condition. However, populations responded very differently to water treatments. Plants from annual populations showed a similar response to drought condition with little variation among maternal families, suggesting a history of selection favouring genotypes with high allocation to reproduction when water availability is low. Plants from annual populations also expressed the highest level of plasticity. For the perennial populations, one showed a large variation among maternal families in resource allocation and expressed significant negative genetic correlations between reproductive and vegetative biomass under drought. The other perennial population showed less variation in response to treatment and had trait values similar to those of the annuals, although it was significantly less plastic. We stress the importance of considering intraspecific variation in response to environmental change such as drought, as conspecific plants exhibited very different abilities and strategies to respond to high versus low water availability even among geographically close populations.