Swiss Federal Institute for Forest, Snow and Landscape Research

About: Swiss Federal Institute for Forest, Snow and Landscape Research is a facility organization based out in Birmensdorf, Switzerland. It is known for research contribution in the topics: Climate change & Soil water. The organization has 1256 authors who have published 3222 publications receiving 161639 citations. The organization is also known as: WSL.

Agricultural policies exacerbate honeybee pollination service supply-demand mismatches across Europe.

Abstract: Declines in insect pollinators across Europe have raised concerns about the supply of pollination services to agriculture. Simultaneously, EU agricultural and biofuel policies have encouraged substantial growth in the cultivated area of insect pollinated crops across the continent. Using data from 41 European countries, this study demonstrates that the recommended number of honeybees required to provide crop pollination across Europe has risen 4.9 times as fast as honeybee stocks between 2005 and 2010. Consequently, honeybee stocks were insufficient to supply >90% of demands in 22 countries studied. These findings raise concerns about the capacity of many countries to cope with major losses of wild pollinators and highlight numerous critical gaps in current understanding of pollination service supplies and demands, pointing to a pressing need for further research into this issue.

A trade-off between plant and soil carbon storage under elevated CO2.

Abstract: Terrestrial ecosystems remove about 30 per cent of the carbon dioxide (CO2) emitted by human activities each year1, yet the persistence of this carbon sink depends partly on how plant biomass and soil organic carbon (SOC) stocks respond to future increases in atmospheric CO2 (refs. 2,3). Although plant biomass often increases in elevated CO2 (eCO2) experiments4–6, SOC has been observed to increase, remain unchanged or even decline7. The mechanisms that drive this variation across experiments remain poorly understood, creating uncertainty in climate projections8,9. Here we synthesized data from 108 eCO2 experiments and found that the effect of eCO2 on SOC stocks is best explained by a negative relationship with plant biomass: when plant biomass is strongly stimulated by eCO2, SOC storage declines; conversely, when biomass is weakly stimulated, SOC storage increases. This trade-off appears to be related to plant nutrient acquisition, in which plants increase their biomass by mining the soil for nutrients, which decreases SOC storage. We found that, overall, SOC stocks increase with eCO2 in grasslands (8 ± 2 per cent) but not in forests (0 ± 2 per cent), even though plant biomass in grasslands increase less (9 ± 3 per cent) than in forests (23 ± 2 per cent). Ecosystem models do not reproduce this trade-off, which implies that projections of SOC may need to be revised. A synthesis of elevated carbon dioxide experiments reveals that when plant biomass is strongly stimulated by elevated carbon dioxide levels, soil carbon storage declines, and where biomass is weakly stimulated, soil carbon accumulates.

Variation in fine root biomass of three European tree species: Beech (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst.), and Scots pine (Pinus sylvestris L.)

Abstract: Fine roots (<2 mm) are very dynamic and play a key role in forest ecosystem carbon and nutrient cycling and accumulation We reviewed root biomass data of three main European tree species European beech, (Fagus sylvatica L), Norway spruce (Picea abies L Karst) and Scots pine (Pinus sylvestris L), in order to identify the differences between species, and within and between vegetation zones, and to show the relationships between root biomass and the climatic, site and stand factors The collected literature consisted of data from 36 beech, 71 spruce and 43 pine stands The mean fine root biomass of beech was 389 g m−2, and that of spruce and pine 297 g m−2 and 277 g m−2, respectively Data from pine stands supported the hypothesis that root biomass is higher in the temperate than in the boreal zone The results indicated that the root biomass of deciduous trees is higher than that of conifers The correlations between root biomass and site fertility characteristics seemed to be species specific

1300 years of climatic history for Western Central Asia inferred from tree-rings:

Abstract: More than 200 000 ring-width measurements from 384 trees were obtained for 20 individual sites ranging from the lower to upper local timber-lines in the Northwest Karakorum of Pakistan and the Southern Tien Shan of Kirghizia. Samples were obtained predominantly from juniper species ( Juniperus) and were analysed to reconstruct regional climatic variation patterns in Western Central Asia since ad 618. Site distri- bution represents diverse ecological conditions (e.g., combinations of temperature and moisture stress) within the Karakorum and Tien Shan mountains, permitting both intra-montane and inter-montane comparisons of chronologies. Three different types of chronologies ree ecting interannual-, decadal- and centennial-scale ring- width variations were calculated: a statistic skeleton-plotting technique was used to identify ring-width pointer years (interannual); a 101-year kernel e lter was used to identify decadal-scale variations; and, for a subset of long-lived trees, the mean ring-width of the entire single series was used to identify centennial trends. After extracting and calibrating each of these three distinct wavelengths in ring-width variation, the results were combined into a comprehensive reconstruction ree ecting primarily temperature e uctuations in Western Central Asia since ad 618. The nature and the temporally changing strength of the climatic signals of this reconstruction are discussed in detail. A maximum latewood density record of Pinus tienschanica from Central Tien Shan was used as a predictor series to calibrate and validate tree-ring-width variation. In so doing, we link our results to the circumpolar maximum latewood-density network (Briffa et al., 1998a; 1998b; Schweingruber and Briffa, 1996).

Low growth resilience to drought is related to future mortality risk in trees

Abstract: Severe droughts have the potential to reduce forest productivity and trigger tree mortality. Most trees face several drought events during their life and therefore resilience to dry conditions may be crucial to long-term survival. We assessed how growth resilience to severe droughts, including its components resistance and recovery, is related to the ability to survive future droughts by using a tree-ring database of surviving and now-dead trees from 118 sites (22 species, >3,500 trees). We found that, across the variety of regions and species sampled, trees that died during water shortages were less resilient to previous non-lethal droughts, relative to coexisting surviving trees of the same species. In angiosperms, drought-related mortality risk is associated with lower resistance (low capacity to reduce impact of the initial drought), while it is related to reduced recovery (low capacity to attain pre-drought growth rates) in gymnosperms. The different resilience strategies in these two taxonomic groups open new avenues to improve our understanding and prediction of drought-induced mortality.