• Energy Research
• 2021-2025close
• natural sciences close
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Most of the world’s mountain glaciers have been retreating for more than a century in response to climate change. Glacier retreat is evident on all continents, and the rate of retreat has accelerated during recent decades. Accurate, spatially explicit information on the position of glacier margins over time is useful for analyzing patterns of glacier retreat and measuring reductions in glacier surface area. This information is also essential for evaluating how mountain ecosystems are evolving due to climate warming and the attendant glacier retreat. Here, we present a non-comprehensive spatially explicit dataset showing multiple positions of glacier fronts since the Little Ice Age (LIA) maxima, including many data from the pre-satellite era. The dataset is based on multiple historical archival records including topographical maps; repeated photographs, paintings, and aerial or satellite images with a supplement of geochronology; and own field data. We provide ESRI shapefiles showing 728 past positions of 94 glacier fronts from all continents, except Antarctica, covering the period between the Little Ice Age maxima and the present. On average, the time series span the past 190 years. From 2 to 46 past positions per glacier are depicted (on average: 7.8).

AbstractIn the present study, we analyze a field-based seven-year data series of surface mass-balance measurements collected during 2011/12 to 2017/18 on Naradu Glacier, western Himalaya, India. The average annual specific mass balance for the said period is − 0.85 m w.e. with the maximum ablation of − 1.15 m w.e. The analysis shows that the topographic features, south and southeast aspects and slopes between 7 to 24 degrees are the reasons behind the maximum ablation from a particular zone. The causes of surface mass balance variability have been analyzed through multiple linear regression analyses (MLRA) by taking temperature and precipitation as predictors. The MLRA demonstrates that 71% of the observed surface mass balance variance can be explained by temperature and precipitation. It clearly illustrates the importance of summer temperature, which alone explains 64% variance of surface mass balance. The seasonal analysis shows that most of the surface mass balance variability is described by summer temperature and winter precipitation as two predictor variables. Among monthly combinations, surface mass balance variance is best characterized by June temperature and September precipitation.

AbstractAimAgriculture is one of the greatest pressures on biodiversity. Regional studies have shown that the presence of natural habitat and landscape heterogeneity are beneficial for biodiversity in agriculture, but it remains unclear whether their importance varies geographically. Here, we use local biodiversity data to determine which local and landscape variables are most associated with biodiversity patterns and whether their association varies between tropical and non‐tropical regions.LocationGlobal terrestrial area in forest biomes.Major taxa studiedMore than 21,000 species of vertebrates, invertebrates, plants and other taxa.MethodsWe used generalized linear mixed‐effects models to analyse the relationships between either community total abundance or species richness (derived from the PREDICTS database) and a number of site‐level (predominant land use and land‐use intensity) and landscape‐level variables (distance to forest, the percentage of natural habitat in the surrounding landscape, landscape homogeneity, the number of land‐cover types in the landscape, and total fertilizer application). We compared the associations of these variables with biodiversity in tropical and non‐tropical regions.ResultsIn most cases, changes in biodiversity associated with landscape‐level variables were greater than those associated with local land use and land‐use intensity. Increased natural habitat availability was associated with the most consistent increases in biodiversity. Landscape homogeneity was also important but showed different directions of biodiversity change between regions. Associations with fertilizer application or the number of land‐cover types were generally weaker, although still of greater magnitude than for the local land‐use measures.Main conclusionsOur results highlight similarities and differences in the association of local‐ and landscape‐scale variables with local biodiversity in tropical and non‐tropical regions. Landscape natural habitat availability had a consistent positive association with biodiversity, highlighting the key role of landscape management in the maintenance of biodiversity in croplands. Landscape‐scale variables were almost always associated with greater changes in biodiversity than the local‐scale measures.

Glaciers are retreating globally, and the resulting ice-free areas provide an experimental system for understanding species colonization patterns, community formation, and dynamics. The last several years have seen crucial advances in our understanding of biotic colonization after glacier retreats, resulting from the integration of methodological innovations and ecological theories. Recent empirical studies have demonstrated how multiple factors can speed up or slow down the velocity of colonization and have helped scientists develop theoretical models that describe spatiotemporalchanges in community structure. There is a growing awareness of how different processes (e.g., time since glacier retreat, onset or interruption of surface processes, abiotic factors, dispersal, biotic interactions) interact to shape community formation and, ultimately, their functional structure through succession. Here, we examine how these studies address key theoretical questions about community dynamics and show how classical approaches are increasingly being combined with environmental DNA metabarcoding and functional trait analysis to document the formation of multitrophic communities, revolutionizing our understanding of the biotic processes that occur following glacier retreat.

Cassava utilisation in Malawi is negatively affected by rapid deterioration of fresh roots, primarily caused by postharvest physiological deterioration (PPD). A study was conducted to assess farmers’ knowledge and approaches used to minimize losses from PPD. Multi-stage sampling was used to identify districts, Extension Planning Areas (EPA’s) and farmers. Data were collected from 519 farmers using a structured questionnaire. Results revealed that PPD (74.0%) was the major post-harvest constraint followed by pests and diseases (62.1%). Farmers had varying knowledge levels on signs and causes of PPD. They were knowledgeable on PPD signs with 91.5% ably identifying PPD through change of pulp colour. The farmers also had moderate knowledge on causes of PPD, citing high temperature (57.6%) and over-staying of roots (56.2%) as main causes of PPD. Key methods for preventing PPD are: storage (43.0%) and piece-meal harvesting (40.4%). Only 2.6% of the farmers exploited varietal difference in dealing with PPD as some varieties (Sauti, Mpuma, Ching’amba, and Kalasa) take three to five days before showing PPD signs. Farmers’ knowledge levels and PPD preventive methods could be strengthened through: provision of training on post-harvest handling, improvement in storage and processing technologies; and application of advanced breeding techniques to exploit genetic variation in cassava germplasm.

Agricultural land abandonment due to biophysical and socioeconomic constraints is increasing across Europe. Meanwhile there is also an increase in bioenergy demand. This study assessed woody crop performance on several relevant types of marginal agricultural land in Europe, based on field experiments in Latvia, Spain and Ukraine. In Latvia, hybrid aspen was more productive than birch and alder species, and after eight years produced 4.8 Mg ha−1 y−1 on stony soil with sandy loam texture, when best clone and treatment combination was selected. In Spain, Siberian elm produced up to 7.1 Mg ha−1 y−1 on stony, sandy soil with low organic carbon content after three triennial rotations. In Ukraine, willow plantations produced a maximum of 10.8 Mg ha−1 y−1 on a soil with low soil organic carbon after second triennial rotation. The productivity was higher when management practices were optimized specifically to address the limiting factors of a site. Longer rotations and lower biomass yields compared to high-value land can be expected when woody crops are grown on similar marginal agricultural land shown in this study. Future studies should start here and investigate to what extent woody crops can contribute to rural development under these conditions.