Combining process-based models for future biomass assessment at landscape scale

Abstract

We need an integrated assessment of the bioenergy production at landscape scale for at least three main reasons: (1) it is predictable that we will soon have landscapes dedicated to bioenergy productions; (2) a number of ''win-win'' solutions combining several dedicated energy crops have been suggested for a better use of local climate, soil mosaic and production systems and (3) ''well-to-wheels'' analyses for the entire bioenergy production chain urge us to optimize the life cycle of bioenergies at large scales. In this context, we argue that the new generation of landscape models allows in silico experiments to estimate bioenergy distributions (in space and time) that are helpful for this integrated assessment of the bioenergy production. The main objective of this paper was to develop a detailed modeling methodology for this purpose. We aimed at illustrating and discussing the use of mechanistic models and their possible association to simulate future distributions of fuel biomass. We applied two separated landscape models dedicated to human-driven agricultural and climatedriven forested neighboring patches. These models were combined in the same theoretical (i.e. virtual) landscape for present as well as future scenarios by associating realistic agricultural production scenarios and B2-IPCC climate scenarios depending on the bioenergy type (crop or forest) concerned in each landscape patch. We then estimated esthetical impacts of our simulations by using 3D visualizations and a quantitative ''depth'' index to rank them. Results first showed that the transport cost at landscape scale was not correlated to the total biomass production, mainly due to landscape configuration constraints. Secondly, averaged index values of the four simulations were conditioned by agricultural practices, while temporal trends were conditioned by gradual climate changes. Thirdly, the most realistic simulated landscape combining intensive agricultural practices and climate change with atmospheric CO2 concentration increase corresponded to the lowest and unwanted bioenergy conversion inefficiency (the biomass production ratio over 100 years divided by the averaged transport cost) and to the most open landscape. Managing land use and land cover changes at landscape scale is probably one of the most powerful ways to mitigate negative (or magnify positive) effects of climate and human decisions on overall biomass productions. (Résumé d'auteur

Evolution of land use-change modeling: routes of different schools of knowledge

“…Particularly, a systemic approach is able to examine the feedback that exists within socio-ecological systems. In this regard, many studies Gaucherel et al 2010;Valbuena et al 2010;Sohl et al 2010;Verburg et al 2010;Courtney et al 2015) emphasize the need to combine modeling approaches and techniques in order to further reduce the uncertainties of future landscapes. In order to monitor, model, and assess the interactions among and in humans/nature, temporal dimensions of landscapes have to be considered as significant as their spatial dimensions.…”

Modeling direct and indirect climate change impacts on ecological networks: a case study on breeding habitat of Dutch meadow birds

“…This practice is currently not profitable, but the profitability of these alternatives is highly dependent on prices of agricultural produce compared to fuel prices, CO 2 emission prices and the societal demand for more sustainable energy sources (Dale et al 2011;Kuhlman et al 2013). It may therefore become an attractive land use option under scenarios of global change that include considerable climate effects (Gaucherel et al 2010). In this paper, we therefore assumed a switch to bioenergy crops in those locations where dairy farming is no longer profitable.…”

“…A switch from dairy farming to bioenergy crops does not only lead to conversion of grassland into a land use type that is unsuitable for meadow birds, but the concomitant loss of landscape openness (Gaucherel et al 2010) may also reduce the habitat suitability of the remaining grassland. Since meadow birds rely on actively deterring predators by displaying aggressive behavior, they require good predator visibility (Dyrcz et al 1981; Van der Vliet et al 2008).…”

“…A common adaptation option in agriculture that is explored is growing bioenergy crops. A large scale switch to bioenergy crops may lead to significant landscape changes (Gaucherel et al 2010). Although it is increasingly recognized that projections of climate change impacts on ecological network quality also should include effects of autonomous land use changes (Barbet-Massin et al 2012;Van Teeffelen et al 2012;Jongsomjit et al 2013;Riordan and Rundel 2014), land use changes driven by climate change itself are rarely taken into account (but see Bakker et al 2014).…”

Quantifying biodiversity impacts of climate change and bioenergy: the role of integrated global scenarios

“…Integrated assessment models (IAMs) of climate and land-use change can be used to assess global bioenergy potentials in different socio-economic scenarios and under various constraints. However, these models do not account for specific local, regional and landscape-scale opportunities and constraints that are important for assessing the impacts of bioenergy-related land-use change (Davis et al 2011) and for mitigating the negative impacts from bioenergy (Gaucherel et al 2009). Furthermore, the mitigation effect of bioenergy depends on the source, and may be significantly reduced or even be multifold exceeded by emissions from associated land-use changes (Fargione et al 2008).…”