Towards Participatory Integrated Valuation and Modelling of Ecosystem Services under Land-use Change

in Journal of Land Use Science (in press)

The lack of consideration for Ecosystem Services (ES) values in current decision-making is recognised as one of the main reasons leading to an intense competition and arguably unsustainable use of well ... [more ▼]

The lack of consideration for Ecosystem Services (ES) values in current decision-making is recognised as one of the main reasons leading to an intense competition and arguably unsustainable use of well-located available land. In this paper, we present a framework for the Valuation Of Terrestrial Ecosystem Services (VOTES), aiming at structuring a methodology that is applicable for valuing ES in a given area through a set of indicators that are both meaningful for local actors and scientifically constructed. Examples from a case study area in central Belgium are used to illustrate the methodology: a stepwise procedure starting with the valuation of ES at present. The valuation of the social, biophysical and economic dimensions of ES are based on current land-use patterns. Subsequently, scenarios of land-use change are used to explore potential losses (and/or gains) of ES in the future of the study area. With the VOTES framework, we aim at [1] incorporating stakeholders inputs to widen the valuation process and increase trust in policy-oriented approach; [2] integrating valuation of ES with a sustainable development stance accounting for land-use change; and [3] developing suggestions to policy-makers for integrating ES monitoring in policy developments. [less ▲]

Rates of consumption of atmospheric CO2 through the weathering of loess during the next 100 yr of climate change

in Biogeosciences (2013), 10

Quantifying how C fluxes will change in the future is a complex task for models because of the coupling between climate, hydrology, and biogeochemical reactions. Here we investigate how pedogenesis of the ... [more ▼]

Quantifying how C fluxes will change in the future is a complex task for models because of the coupling between climate, hydrology, and biogeochemical reactions. Here we investigate how pedogenesis of the Peoria loess, which has been weathering for the last 13 kyr, will respond over the next 100 yr of climate change. Using a cascade of numerical models for climate (ARPEGE), vegetation (CARAIB) and weathering (WITCH), we explore the effect of an increase in CO2 of 315 ppmv (1950) to 700 ppmv (2100 projection). The increasing CO2 results in an increase in temperature along the entire transect. In contrast, drainage increases slightly for a focus pedon in the south but decreases strongly in the north. These two variables largely determine the behavior of weathering. In addition, although CO2 production rate increases in the soils in response to global warming, the rate of diffusion back to the atmosphere also increases, maintaining a roughly constant or even decreasing CO2 concentration in the soil gas phase. Our simulations predict that temperature increasing in the next 100 yr causes the weathering rates of the silicates to increase into the future. In contrast, the weathering rate of dolomite – which consumes most of the CO2 – decreases in both end members (south and north) of the transect due to its retrograde solubility. We thus infer slower rates of advance of the dolomite reaction front into the subsurface, and faster rates of advance of the silicate reaction front. However, additional simulations for 9 pedons located along the north–south transect show that the dolomite weathering advance rate will increase in the central part of the Mississippi Valley, owing to a maximum in the response of vertical drainage to the ongoing climate change. The carbonate reaction front can be likened to a terrestrial lysocline because it represents a depth interval over which carbonate dissolution rates increase drastically. However, in contrast to the lower pH and shallower lysocline expected in the oceans with increasing atmospheric CO2, we predict a deeper lysocline in future soils. Furthermore, in the central Mississippi Valley, soil lysocline deepening accelerates but in the south and north the deepening rate slows. This result illustrates the complex behavior of carbonate weathering facing short term global climate change. Predicting the global response of terrestrial weathering to increased atmospheric CO2 and temperature in the future will mostly depend upon our ability to make precise assessments of which areas of the globe increase or decrease in precipitation and soil drainage. [less ▲]

Growth of subtropical forests in Miocene Europe : The roles of carbon dioxide and Antarctic ice volume.

in Geology (2012)

Modelling European tree species distribution change over the Holocene

Conference (2012, March 01)

The postglacial re-colonization of Europe by temperate tree species from a few glacial refugia during the Holocene (10,000 BP) is a very interesting case to study the mechanisms of the vegetation dynamics ... [more ▼]

The postglacial re-colonization of Europe by temperate tree species from a few glacial refugia during the Holocene (10,000 BP) is a very interesting case to study the mechanisms of the vegetation dynamics. The relative roles that played the climate conditions, the species dispersal capacities and the competition between species in the re-colonization rates remain controversial. We investigate these different aspects with the CARAIB dynamic vegetation model (CARAIB DVM). Transient runs were performed over the Holocene using the HadCM3 AOGCM-reconstructed climate. European-wide species migration at 0.5° x 0.5° is represented in the model using migration rates derived from a high resolution cellular automaton, CATS-UPSCALE. Individual tree species migration rates were pre-calculated with CATS-UPSCALE every 1000 years over each grid cell used by the DVM in the climatic conditions reconstructed by the AOGCM. The impacts of competition on plant dispersal are not taken into account by the automaton. Thus, in CARAIB, a function has been constructed to reduce the potential CATS migration rates in competition conditions. It is based on the species dispersal kernel and on the net primary productivity of the different species present on the grid cell. The migration of one species, from its 10,000 BP refugia, is studied within a landscape defined by a set of other species for which no dispersal limitations are assumed. Here, we illustrate the results obtained for two wind-dispersed (Abies alba and Picea abies) and for a no wind-dispersed (Fagus sylvatica) tree species. The speeds and the paths of the postglacial spread obtained with the DVM are compared to the past distributions of the three species reconstructed from pollen and macrofossil data. The Holocene climate conditions simulated by the HadCM3 AOGCM do not constrain the European re-colonization of the studied species, except in Scandinavia at the beginning of the period for Picea abies. We observe that, during the past 10,000 years, species occupied regions where climate conditions were different from present observed species climate requirements, notably in the 10k species refugia. This result may imply that at present the species do not occupy their potential distribution area and thus that the postglacial re-colonization is not completed yet. We also show that species dispersal capacities cannot explain the observed species migration over the Holocene and that competition has played an important role. Indeed, when we use the potential migration rates (no competition), species spread too fast. [less ▲]

Can accurate kinetic laws be created to describe chemical weathering ?

in Comptes Rendus Geoscience (2012), 344

Knowledge of the mechanisms and rates of mineral dissolution and growth, especially close to equilibrium, is essential for describing the temporal and spatial evolution of natural processes like ... [more ▼]

Knowledge of the mechanisms and rates of mineral dissolution and growth, especially close to equilibrium, is essential for describing the temporal and spatial evolution of natural processes like weathering and its impact on CO2 budget and climate. The Surface Complexation approach (SC) combined with Transition State Theory (TST) provides an efficient framework for describing mineral dissolution over wide ranges of solution composition, chemical affinity, and temperature. There has been a large debate for several years, however, about the comparative merits of SC/TS versus classical growth theories for describing mineral dissolution and growth at near-to-equilibrium conditions. This study considers recent results obtained in our laboratory on oxides, hydroxides, silicates, and carbonates on near-equilibrium dissolution and growth via the combination of complementary microscopic and macroscopic techniques including hydrothermal atomic force microscopy, hydrogen-electrode concentration cell, mixed flow and batch reactors. Results show that the dissolution and precipitation of hydroxides, kaolinite, and hydromagnesite powders of relatively high BET surface area closely follow SC/TST rate laws with a linear dependence of both dissolution and growth rates on fluid saturation state (V) even at very close to equilibrium conditions (jDGj < 500 J/mol). This occurs because sufficient reactive sites (e.g. at kink, steps, and edges) are available at the exposed faces for dissolution and/or growth, allowing reactions to proceed via the direct and reversible detachment/attachment of reactants at the surface. In contrast, for magnesite and quartz, which have low surface areas, fewer active sites are available for growth and dissolution. Such minerals exhibit rates dependencies on V at near equilibrium conditions ranging from linear to highly non-linear functions of V, depending on the treatment of the crystals before the reaction. It follows that the form of the f(DG) function describing the growth and dissolution of minerals with low surface areas depends on the availability of reactive sites at the exposed faces and thus on the history of the mineral-fluid interaction and the hydrodynamic conditions under which the crystals are reacted. It is advocated that the crystal surface roughness could serve as a proxy of the density of reactive sites. The consequences of the different rate laws on the quantification of loess weathering along the Mississippi valley for the next one hundred years are examined. [less ▲]

Growth of subtropical forests in Miocene Europe: The roles of carbon dioxide and Antarctic ice volume

in Geology (2012), 40

The middle Miocene is a crucial period for the evolution of apes, and it corresponds to their appearance in Europe. The dispersion of apes was made possible by tectonic changes and the expansion of their ... [more ▼]

The middle Miocene is a crucial period for the evolution of apes, and it corresponds to their appearance in Europe. The dispersion of apes was made possible by tectonic changes and the expansion of their habitat, (sub-) tropical forest, in Europe. The context in which the middle Miocene climatic optimum occurred still lacks constraints in terms of atmospheric pCO2 and ice-sheet volume and extent. Using a coupled atmosphere-ocean general circulation model (GCM) and dynamic vegetation model, we investigated the sensitivity of Miocene climate and vegetation to pCO2 levels and Antarctic ice-sheet confi gurations. Our results indicate that higher than present pCO2 is necessary to simulate subtropical forest in Western and Central Europe during the middle Miocene, but that a threshold at high pCO2 makes subtropical forest partly collapse. Moreover, removing ice over Antarctica modifi es oceanic circulation and induces warmer and slightly wetter conditions in Europe, which are consistent with the expansion of subtropical forest. These results suggest that a small East Antarctic Ice Sheet (25% of present-day ice volume) together with higher than present pCO2 values are in better agreement with available European middle Miocene data. [less ▲]

Modelling European tree species distribution change over the Holocene

Conference (2011, September)

The postglacial re-colonization of Europe by temperate tree species from a few glacial refugia during the Holocene (10,000 BP) is a very interesting case to study the mechanisms of the vegetation dynamics ... [more ▼]

The postglacial re-colonization of Europe by temperate tree species from a few glacial refugia during the Holocene (10,000 BP) is a very interesting case to study the mechanisms of the vegetation dynamics. The relative roles that played the climate conditions, the species dispersal capacities and the inter-specific competition in the re-colonization rates remain controversial. We investigate these different aspects with the CARAIB dynamic vegetation model (CARAIB DVM). Transient runs were performed over the Holocene using the HadCM3 AOGCM-reconstructed climate. European-wide species migration at 0.5° x 0.5° is represented in the model using migration rates derived from a high resolution cellular automaton, CATS-UPSCALE. Individual tree species migration rates were pre-calculated with CATS-UPSCALE every 1000 years over each grid cell used by the DVM in the climatic conditions reconstructed by the AOGCM. The impacts of competition between species on plant dispersal are not taken into account by the automaton. Thus, in CARAIB, a function has been constructed to reduce the potential CATS migration rates in competition conditions. It is based on the species dispersal kernel and on the species net primary productivity. The migration of one species, from its 10,000 BP refugia, is studied within a landscape defined by a set of other species for which no dispersal limitations are assumed. Here, we illustrate the results obtained for two wind-dispersed (Abies alba and Picea abies) and for a no wind-dispersed (Fagus sylvatica) tree species. We compare the HadCM3 climate outputs with reconstructions of some climate variables from fossil dataset. The speeds and the paths of the postglacial spread obtained with the DVM are compared to the past distributions of the three species reconstructed from pollen and macrofossil data. The Holocene climate conditions simulated by the HadCM3 AOGCM do not constrain the European re-colonization of the studied species, except in Scandinavia at the beginning of the period for Picea abies. We observe that, during the past 10,000 years, species occupied regions where climate conditions were different from present observed species climate requirements, notably in the 10k species refugia. This result may imply that at present the species do not occupy their potential distribution area and thus that the postglacial re-colonization is not completed yet. We also show that species dispersal capacities cannot explain the observed species migration over the Holocene and that competition has played an important role. Indeed, when we use the potential migration rates (no competition), species migration rates are too fast. [less ▲]

Sustainability of tropical forest biodiversity and services under climate and human pressure (BIOSERF): tracking the regeneration of human-used plants through dispersal by the animal community

Conference (2011, June)

The objective of the BIOSERF project is to assess the sustainability of a tropical humid forest ecosystem and the local human communities in southern Congo under future climate, demographic and societal ... [more ▼]

The objective of the BIOSERF project is to assess the sustainability of a tropical humid forest ecosystem and the local human communities in southern Congo under future climate, demographic and societal changes. The project focuses on the interactions between flora, fauna and local human population to understand the processes affecting biodiversity and ecosystem services in tropical humid areas, with the objective of setting up mechanisms to preserve local biodiversity. In close collaboration with a local NGO, it will use a dynamic vegetation model (CARAIB) which will be integrated within an agent-based model, to analyze the impacts of different ecosystem services in a tropical humid area, e.g. the production of medicinal plants, of wood and other forest products, or the services provided by the building of natural reserves. The vegetation model will be upgraded to take into account the process of regeneration of several plant species, selected for their use by local human populations, through a quantitative and qualitative description of plant dispersal by the animal community. To do so, a selection of five tree species frequently or traditionally used will be made based on the results of a sociological survey. Observations (direct or through camera trapping) of a sample of the selected species will allow identifying the main dispersers and the pattern of seed shadow they generate. Integrated into the CARAIB model, these results will allow figuring how the evolution of the dispersal community under pressures of climate change, habitat loss and hunting, but also potentially placed under managed protection could affect the services available to the human community. [less ▲]

Simulating the Holocene re-colonization of Europe by tree species using dynamic vegetation models

Poster (2011, April)

At the beginning of the Holocene (10.000 BP) started a progressive re-colonization of Europe by temperate tree species from a limited number of glacial refugia. To reconstruct the speed, seemingly species ... [more ▼]

At the beginning of the Holocene (10.000 BP) started a progressive re-colonization of Europe by temperate tree species from a limited number of glacial refugia. To reconstruct the speed, seemingly species-specific, and the routes of the postglacial spread of European tree species, fossil records collected from various localities in Europe are invaluable. However, the relative roles of climatic fluctuations, dispersal capacities of individual species, and inter-specific competition in controlling the re-colonization rates remain controversial. We investigate these different aspects with two dynamic vegetation models (DVM), LPJ-GUESS and CARAIB. Transient runs of both models were performed over the Holocene, using HadCM3 GCM-reconstructed climate. Large-scale species migration at 0.5◦ x0.5◦ is represented in these models using migration rates derived from a small-scale cellular automaton, CATS. Individual tree species migration rates were pre-calculated with CATS every 1000 years over each grid cell used by the DVMs in the climatic conditions reconstructed by the GCM. In the DVMs, these migration speeds were influenced by the response to competition from other species, expressed as a function of net primary production ratios. The DVMs were used to study the migration of one species, from its 10.000 BP refugia, within a landscape defined by a set of other species for which no dispersal limitations are assumed. Here, we illustrate the results obtained for wind-dispersed tree species and compare them to their past distributions reconstructed from pollen and macrofossil data. [less ▲]

Responses of European forest ecosystems to 21(st) century climate: assessing changes in interannual variability and fire intensity

in iForest: Biogeosciences and Forestry (2011), 4

Significant climatic changes are currently observed and, according to projections, will be strengthened over the 21(st) century throughout the world with the continuing increase of the atmospheric CO2 ... [more ▼]

Significant climatic changes are currently observed and, according to projections, will be strengthened over the 21(st) century throughout the world with the continuing increase of the atmospheric CO2 concentration. Climate will be generally warmer with notably changes in the seasonality and in the precipitation regime. These changes will have major impacts on the biodiversity and the functioning of natural ecosystems. The CARAIB dynamic vegetation model driven by the ARPEGE/Climate model under forcing from the A2 IPCC emission scenario is used to illustrate and analyse the potential impacts of climate change on forest productivity and distribution as well as fire intensity over Europe. The potential CO2 fertilizing effect is studied throughout transient runs of the vegetation model over the 1961-2100 period assuming constant and increasing atmospheric CO2 concentration. Without fertilisation effect, the net primary productivity (NPP) might increase in high latitudes and altitudes (by up to 40 % or even 60-100 %) while it might decrease in temperate (by up to 50 %) and in warmer regions, e.g., Mediterranean area (by up to 80 %). This strong decrease in NPP is associated with recurrent drought events occurring mostly in summer time. Under rising CO2 concentration, NPP increases all over Europe by as much as 25-75%, but it is not clear whether or not soils might sustain such an increase. The model indicates also that interannual NPP variability might strongly increase in the areas which will undergo recurrent water stress in the future. During the years exhibiting summer drought, the NPP might decrease to values much lower than present-day average NPP even when CO2 fertilization is included. Moreover, years with such events will happen much more frequently than today. Regions with more severe droughts might also be affected by an increase of wildfire frequency and intensity, which may have large impacts on vegetation density and distribution. For instance, in the Mediterranean basin, the area burned by wildfire can be expected to increase by a factor of 3-5 at the end of the 21(st) century compared to present. [less ▲]