Ecological goods and services | EPFL Graph Search

Ecological goods and services (EG&S) are the economical benefits (goods and services) arising from the ecological functions of ecosystems. Such benefits accrue to all living organisms, including animals and plants, rather than to humans alone. However, there is a growing recognition of the importance to society that ecological goods and services provide for health, social, cultural, and economic needs. Introduction Examples of ecological goods include clean air, and abundant fresh water. Examples of ecological services include purification of air and water, maintenance of biodiversity, decomposition of wastes, soil and vegetation generation and renewal, pollination of crops and natural vegetation, groundwater recharge through wetlands, seed dispersal, greenhouse gas mitigation, and aesthetically pleasing landscapes. The products and processes of ecological goods and services are complex and occur over long periods of time. They are a sub-category of public goods. The concern

Ecological response of tree saplings to simulated climate change along an elevational gradient (CLIMARBRE)

María Paula Sanginés De Cárcer

Switzerland will face higher temperature increases than the global average, which will have strong impacts on the mountain ecosystems. How tree species will respond to future climate change scenarios, and what mechanisms will they adopt, remains as a gap of knowledge in ecological research. Foresters will have to make short-term decisions and plan future managements under the great uncertainty of climate change and they demand answers to know if the current species will cope with the predicted climate change and to what extent the ecological goods and services will be affected (e.g. timber industry). The project CLIMARBRE was developed in order to ease and support their decision making by providing an advanced knowledge about the responses of beech and spruce regeneration to simulated climate change (specifically, warmer and drier conditions) in the wooded pastures of the Swiss Jura mountains. This project, which was built on the interface between fundamental research in forestry ecology and applied sciences, should attract the attention of foresters, managers of natural environments and of the general public. By using transplantation along an elevational gradient, in the Jura mountains, ârealisticâ climate conditions were created to specifically simulated three potential future climatic scenarios from the IPCC (from A1B to A2). This space for time approach enabled the assessment of saplingsâ responses to simulated climate change and their acclimation abilities. Saplings adapted to subalpine conditions at 1350 m were collected and transplanted towards lower altitudes exposing them to an average increase of 6.3áµC and a reduction in 30% of precipitation, at the lowest site throughout the study period. The main findings include i) a longer growing season due to induced-elevation warming (downward shift) could not fully account for the species-specific positive growth responses; (ii) the contrasting species growth responses were linked to different sensitivities to elevated vapor-pressure deficits; (iii) models could better account for the growth response to warming after incorporating extreme climatic events and their effects; iv) beech leaves showed an increase of xeromorphism through the increase of the cuticle thickness, vein network and smaller stomata, associated, to a higher leaf area v) which allowed it to grow in warmer conditions while coping with an increase of evaporative; vi) and finally, the linkage between responses at tree, leaf, tissue and soil level, through a multiple level approach, improved the mechanistic understanding of these species capacities to respond to simulated climate change.

EPFL2017

Towards simple tools to assess functional effects of contaminants on natural microbial and invertebrate sediment communities

Sophie Campiche

Surface sediments can accumulate contaminants that affect microorganisms and invertebrates and disturb benthic ecological functions. However, effects of contaminants on ecological functions supported by sediment communities are understudied. Here, we tested the relevance of two simple tools to assess the ecotoxicological effects of metal contamination on natural sediment communities using particulate organic matter breakdown and decomposition as a functional descriptor. To this aim, we performed a 21-day laboratory microcosm experiment to assess the individual and combined effects of Cu and As (nominal concentration of 40 mg kg(-1) dw each) using the bait-lamina method (cellulose, bran flakes, and active coal in PVC strips) as well as artificial tablets (cellulose, bran flakes and active coal embedded in an agar matrix). Sediment toxicity was also evaluated using the standardized ostracod toxicity test. Both the bait-lamina and artificial tablet methods showed low effects of As on organic matter breakdown and decomposition but strong effects of Cu on this important ecological function. Both also showed that the presence of Cu and As in mixture in the sediment induced total inhibition of organic matter breakdown and decomposition. The ostracod toxicity test also showed high toxicity of Cu-spiked and Cu-plus-As-spiked sediments and low toxicity of As-spiked sediments. Besides confirming that artificial organic matter substrates are relevant and useful for assessing the functional effects of contaminants on sediment micro- and macro-organism communities, these results suggest that the proposed methods offer promising perspectives for developing tools for use in assessing functional ecotoxicology in the sediment compartment.

SPRINGER HEIDELBERG2020

Streambank erosion hazard mapping

John Beck

Streambank erosion hazard mapping has received much less attention than flood inundation mapping in the past due to the complexity of the task as well as bank protection works that have reduced bank erosion and unfortunately, the ecological functions of our watercourses at the same time. Damages due to streambank erosion in some flooding contexts are greater than the flood water damages (Loat and Petrasheck, 1997). For these reasons, streambank erosion hazard mapping should be an integral part of flood hazard mapping and methods must be developed to accomplish it. This research proposes a methodology for mapping streambank erosion hazards based on the directives of the Swiss Federal Office for Water and Geology (now within the Swiss Federal Office for the Environment). It permits the calculation of bank failure widths and their probability as opposed to future channel migration paths. This research also investigates the input data necessary for streambank erosion hazard modeling. Geomorphological mapping must be the first step to streambank erosion hazard mapping as it permits the identification of the sediment movements in the catchment. After this step, modeling of streambank erosion can be undertaken. Geofluvial models that combine hydraulic sediment transport and geotechnical modeling are well suited for streambank erosion modeling. The model CCHE1D is such a model and was adapted for the calculation of the streambank erosion hazard on an 8 kilometer reach of the Lower Venoge River, Switzerland. CCHE1D performs one dimensional hydraulic calculations. A shear stress correction function based on channel curvature distributes mean boundary shear stress appropriately to outer and inner bank toes and the phase lag of maximum toe shear stress compared to the apex of the bend curvature is ensured by a convolution of upstream shear stresses. Tension cracking was added to the slab failure algorithm due to its significant effect on bank failure widths. After a bank failure, the cross section shape does not change which allows the flow conditions to remain the same and in turn allows the probability of failure for the modeled bank profile to be evaluated. To gain a better understanding of streambank erosion on the Lower Venoge River, detailed erosion and flow depth monitoring were done on two 1 kilometer river reaches from November 2003 through September 2005. These measurements showed the mass failures to be mainly soil falls and cantilever failures. Measured bank erosion was linearly related to the product of maximum discharge and flood volume. Bank and bed sediment data were also collected for the study reach. Eighty-two cross sections were surveyed in 2004 in the 8 kilometer study reach. A new cross section tool was developed to properly reproduce scour holes in bends. It calculates transverse position and distance, graphs the cross section to allow identification of bank definition points, linearly interpolates, calibrates bed topography parameters based on surveyed cross sections, and interpolates with respect to channel curvature. Hydrological modeling allowed for the generation of input hydrographs for the period January 1979 - February 2005. This information was combined with historically based low probability floods to construct three 300 year discharge series. Flow and erosion measurements allowed for the calibration of roughness and critical shear stress parameters, respectively, in the CCHE1D model. Where detailed erosion measurements were not available, past channel migration served as a guide for estimating the critical shear stress. Calibrated critical shear stress was poorly correlated with measured bank properties indicating the necessity of measuring critical shear stress. A regression equation involving the percentage of fine sand – large silt and the fraction of non-vegetated bank explained 75% of the variation. The three 300 year discharge series were simulated with CCHE1D. Bank failures series were output for each of the banks of the 1149 computational nodes in the study reach. Empirical frequency was used to determine the bank failure width of a given probability. These bank failure widths and their probabilities were used to calculate a streambank erosion danger. To further qualify this danger, it was mapped with a bar proportional to the mean annual simulated erosion rate. The extreme failure width for the entire reach was determined by multiplying the maximum simulated failure width by a safety factor. The erosion hazard in straight reaches is too high showing that the shear stress reduction due to the highly vegetated banks needs to be taken into account better in the shear stress correction function. This research has demonstrated the feasibility of streambank erosion hazard mapping, although the quantity of input data necessary is prohibitive. Data acquisition methods must be researched and improved to reduce costs, and research must be continued to improve understanding of bank failure processes to be included in geofluvial models.