125 research outputs found
Monitoring and modelling landscape dynamics
International audienceChanges in land cover and land use are among the most pervasive and important sources of recent alterations of the Earth's land surface.This special issue also presents new directions in modelling landscape dynamics. Agent-based models have primarily been used to simulate local land use and land cover changes processes with a focus on decision making (Le 2008; Matthews et al. 2007; Parker et al. 2003; Bousquet and Le Page 2001)
Simulated responses of soil organic carbon stock to tillage management scenarios in the Northwest Great Plains
© 2007 Tan et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Local Difference Measures between Complex Networks for Dynamical System Model Evaluation
Acknowledgments We thank Reik V. Donner for inspiring suggestions that initialized the work presented herein. Jan H. Feldhoff is credited for providing us with the STARS simulation data and for his contributions to fruitful discussions. Comments by the anonymous reviewers are gratefully acknowledged as they led to substantial improvements of the manuscript.Peer reviewedPublisher PD
Exploring subtle land use and land cover changes: a framework for future landscape studies
UMR AMAP, Ă©quipe 3International audienceLand cover and land use changes can have a wide variety of ecological effects, including significant impacts on soils and water quality. In rural areas, even subtle changes in farming practices can affect landscape features and functions, and consequently the environment. Fine-scale analyses have to be performed to better understand the land cover change processes. At the same time, models of land cover change have to be developed in order to anticipate where changes are more likely to occur next. Such predictive information is essential to propose and implement sustainable and efficient environmental policies. Future landscape studies can provide a framework to forecast how land use and land cover changes is likely to react differently to subtle changes. This paper proposes a four step framework to forecast landscape futures at fine scales by coupling scenarios and landscape modelling approaches. This methodology has been tested on two contrasting agricultural landscapes located in the United States and France, to identify possible landscape changes based on forecasting and backcasting agriculture intensification scenarios. Both examples demonstrate that relatively subtle land cover and land use changes can have a large impact on future landscapes. Results highlight how such subtle changes have to be considered in term of quantity, location, and frequency of land use and land cover to appropriately assess environmental impacts on water pollution (France) and soil erosion (US). The results highlight opportunities for improvements in landscape modelling
The genome of the Trinidadian guppy, Poecilia reticulata, and variation in the Guanapo population
For over a century, the live bearing guppy, Poecilia reticulata, has been used to study sexual selection as well as local adaptation. Natural guppy populations differ in many traits that are of intuitively adaptive significance such as ornamentation, age at maturity, brood size and body shape. Water depth, light supply, food resources and predation regime shape these traits, and barrier waterfalls often separate contrasting environments in the same river. We have assembled and annotated the genome of an inbred single female from a high-preda- tion site in the Guanapo drainage. The final assembly comprises 731.6 Mb with a scaffold N50 of 5.3 MB. Scaffolds were mapped to linkage groups, placing 95% of the genome assembly on the 22 autosomes and the X-chromosome. To investigate genetic variation in the population used for the genome assembly, we sequenced 10 wild caught male individu- als. The identified 5 million SNPs correspond to an average nucleotide diversity (Ï) of 0.0025. The genome assembly and SNP map provide a rich resource for investigating adap- tation to different predation regimes. In addition, comparisons with the genomes of other Poeciliid species, which differ greatly in mechanisms of sex determination and maternal resource allocation, as well as comparisons to other teleost genera can begin to reveal how live bearing evolved in teleost fish
Climate change impacts on groundwater recharge- uncertainty, shortcomings, and the way forward?
An integrated approach to assessing the regional impacts of climate and socio-
economic change on groundwater recharge is described from East Anglia, UK. Many
factors affect future groundwater recharge including changed precipitation and
temperature regimes, coastal flooding, urbanization, woodland establishment, and
changes in cropping and rotations. Important sources of uncertainty and
shortcomings in recharge estimation are discussed in the light of the results.
The uncertainty in, and importance of, socio-economic scenarios in exploring the
consequences of unknown future changes are highlighted. Changes to soil
properties are occurring over a range of time scales, such that the soils of the
future may not have the same infiltration properties as existing soils. The
potential implications involved in assuming unchanging soil properties are
described. To focus on the direct impacts of climate change is to neglect the
potentially important role of policy, societal values and economic processes in
shaping the landscape above aquifers. If the likely consequences of future
changes of groundwater recharge, resulting from both climate and socio-economic
change, are to be assessed, hydrogeologists must increasingly work with
researchers from other disciplines, such as socio-economists, agricultural
modellers and soil scientists
- âŠ