Martha M. Bakker

Ex ante impact assessment of policies affecting land use, Part B: application of the analytical framework

The use of science-based tools for impact assessment has increasingly gained focus in addressing the complexity of interactions between environment, society, and economy. For integrated assessment of policies affecting land use, an analytical framework was developed. The aim of our work was to apply the analytical framework for specific scenario cases and in combination with quantitative and qualitative application methods. The analytical framework was tested for two cases involving the ex ante impact assessment of: (1) a European Common Agricultural Policy (CAP) financial reform scenario employing a modeling approach and combined with a comprehensive indicator analysis and valuation; and (2) a regional bioenergy policy scenario, employing a fully participatory approach. The results showed that European land use in general is less sensitive to changes in the Common Agricultural Policy, but in the context of regions there can be significant impacts on the functions of land use. In general, the implementation of the analytical framework for impact assessment proved to be doable with both methods, i.e., with the quantitative modeling and with the qualitative participatory approach. A key advantage of using the system of linked quantitative models is that it makes possible the simultaneous consideration of all relevant sectors of the economy without abstaining from a great level of detail for sectors of particular interest. Other advantages lie in the incontestable character of the results. Based on neutral, existing data with a fixed set of settings and regions, an absolute comparability and reproducibility throughout Europe can be maintained. Analyzing the pros and cons of both approaches showed that they could be used complementarily rather than be seen as competing alternatives.

The destination of arable land in a marginal agricultural landscape in South Portugal: an exploration of land use change determinants

This research attempts to investigate what drives three conversions of arable land during the period 1985–2000 in a marginal agricultural landscape in Southern Portugal: afforestation of arable land, abandonment of arable land and regeneration of the agro-silvo-pastoral system. This was done by exploring the associations between these changes and a selection of both biophysical and socio-economic variables in a study area of 44 square km. For each conversion of arable land into one of the three other land use types the descriptive power of the various independent variables were evaluated using logistic regression. By comparing different statistical models (one containing only the biophysical attributes, another model containing only the socio-economic variables and finally a model containing both types of variables) the relative importance of socio-economic and biophysical variables was evaluated. The results show that both the biophysical and socio-economic variables were significantly associated with the occurrences of the land use changes. However, the models containing only the socio-economic variables were stronger related to occurrences of afforestation and regeneration of the montado, whereas the biophysical variables were more related to land abandonment. The landowner type was a significant descriptive variable across all land use change models. The results suggest that local socio-economic factors are significant in explaining the pattern of the conversion of arable land in the study area and for this reason the variety of landowners’ response to the physical conditions deserves more attention in land use change modelling.

Abandonment and expansion of arable land in Europe

Abandonment of arable land is often assumed to happen mostly in marginal areas where the conditions for arable cultivation are relatively unfavorable, whereas arable expansion is expected to occur mostly in areas with favorable conditions. This assumption, used in many land-use change forecasts, was never properly tested, mainly because the relatively short period of full-coverage land-use inventories did not allow a systematic analysis of the phenomena. With the recent release of CORINE 2006 this has changed. In this article, we explore the typical locations of abandonment and expansion of arable land in Europe during the period 1990–2006 by means of logistic regressions. More specifically, we test whether or not locations of abandonment and expansion can be inferred from the location characteristics of arable land in 1990. If the above assumption holds, this should be the case. We demonstrate that although arable expansion indeed happens in locations that resemble the bulk of arable land in 1990 (the presumably favorable locations), arable abandonment does not necessarily happen in locations that resemble the bulk of uncultivated land (that is, the presumably unfavorable locations). In other words, the assumption does not hold. Particularly, areas close to the road network were found to be associated with both high abandonment rates and high expansion rates, which suggest that abandonment is not limited to areas that are marginal in terms of agricultural production.

Land-use change arising from rural land exchange: an agent-based simulation model

IntroductionLand exchange can be a major factor driving land-use change in regions with high pressure on land, but is generally not incorporated in land-use change models. Here we present an agent-based model to simulate land-use change arising from land exchange between multiple agent types representing farmers, nature organizations, and estate owners.MethodsThe RULEX model (Rural Land EXchange) was calibrated and applied to a 300 km2 case study area in the east of the Netherlands. Decision rules about which actor will sell and buy land, as well as which specific land to buy or sell are based on historical observations, interviews, and choice experiments.ResultsA reconstruction of land-use change for the period 2001–2009 demonstrates that RULEX reproduces most observed land-use trends and patterns. Given that RULEX simulates only one mechanism of land-use change, i.e. land exchange, it is conservative in simulating change.ConclusionsWith this model, we demonstrate the potential of incorporating land market processes in an agent-based, land-use change model. This supports understanding of land-use change that is brought about by ownership change, which is an important process in areas where pressure on land is high. The soundness of the process representation was corroborated by stakeholders within the study area. Land exchange models can be used to assess the impact of changes in climate, markets, and policy on land use change, and help to increase effectiveness of alternative land purchasing strategies by stakeholders or spatial planning policy.

Cross sector land use modelling framework

The purpose of the model component in SENSOR is to quantify the effects of a comprehensive set of policies on land use. The need to include interaction between sectors as well as a high level of detail for each sector calls for a combination of sector specific and sector wide models. This chapter describes the modelling system, with emphasis on the linking of the models to a coherent system. Five sectors of significant importance for land use are modelled individually: Forestry, agriculture, urban land use, transport infrastructure and tourism. All models are connected as sub-modules to an economy-wide partial econometric model. In addition, a land cover model is used to disaggregate land use down to 1 km grid resolution.

Changing relationships between land use and environmental characteristics and their consequences for spatially explicit land-use change prediction

Spatially explicit land-use change prediction is often based on environmental characteristics of land-use types, such as soil type and slope, as observed at one time instant. This approach presumes that relationships between land use and environment are constant over time. We argue that such temporal stationarity is uncommon in many land-use systems, and we demonstrate by means of a case study how this may affect the performance of land-use change inference. For this purpose, the spatial distribution of cropland and uncultivated land in Mediterranean Europe in 2000 was studied, as well as recent land-use changes from cropland to uncultivated land and vice versa between 1990 and 2000. Both land-use and land-use change frequencies were captured in regression equations that related them to environmental characteristics. A comparison between these two regression types suggests that many traditional constraints (slope, soil quality, accessibility) have become less important, while climatic variables have gained importance. These results can be explained by lower costs of constraints due to technological and economic developments, and by changes in relative average revenues of different land uses.

The role of governance in agricultural expansion and intensification: a global study of arable agriculture

In this research we studied empirical relationships between agricultural production dynamics and six quantitative World Bank governance indicators for 173 countries between 1975 and 2007. It is hypothesized that in countries with lower quality of governance, agricultural production increases are more likely to be achieved by area expansions than by increases in yields. We distinguished four groups of countries: those with both area and yield increases; those with increasing yields but decreasing area; those with decreasing yields but a growing area; and those with both declines in yields and area. We analyzed differences between these four groups, and also analyzed governance-production relationships within these groups. On average, quality of governance is low in countries with both area and yield increases and high in countries with increasing yields but decreasing area. Countries with declining yields were too few in number to allow for quantitative analyses. The analysis of governance-production relationships within the four groups suggests that countries with a lower quality of governance are more inclined to achieve production increases by expanding agricultural area rather than increasing yields. Additional explanatory value of governance indicators to agricultural production dynamics is generally small, but nevertheless significant in most cases. Our results suggest that, in order for agricultural production to increase without excessive expansions of agricultural area, governance issues should be resolved.

Modelling land change: the issue of use and cover in wide-scale applications

In this article, the underlying causes for the apparent mismatch between land cover and land use in the context of wide-scale land change modelling are explored. A land use–land cover (LU/LC) ratio is proposed as a relevant landscape characteristic. The one-to-one ratio between land use and land cover is revoked by the multiple uses related to one cover type. The introduction of a secondary land use function next to the main primary function is relevant for the characterization of the resulting land cover. Secondary land use poses certain constraints to the productivity of the primary land use. Hence, the secondary land use has implicit land claims and requirements. We propose to relate the LU/LC ratio to the multi-functional nature of land cover, so that trade-off analyses between the primary use and the secondary use become possible. This will allow more realistic land cover projections in large-scale European land use assessment models.

The feasibility of implementing an ecological network in The Netherlands under conditions of global change

ContextBoth global change and policy reform will affect the implementation of the National Ecological Network (NEN) in the Netherlands. Global change refers to a combination of changing groundwater tables arising from climate change and improved economic prospects for farming. Policy reform refers to the abolition of an intermediary organization that organizes land trades with the support of a national land bank.ObjectiveIn this paper we evaluate the effects of these factors on future land acquisition for the NEN.MethodsWe applied an agent-based model of the land market based on sales and purchases between farmers and nature-conservation organizations (establishing the NEN) within a case study area.ResultsOur results demonstrate that future land acquisitions for the NEN are constrained by strong competition for land from farmers due to improved economic prospects for farming. Effects of climate change are that fewer parcels will be sold from farmers to nature-conservation organizations in a dry scenario as compared to a wet scenario. An important constraint for land acquisitions is the low willingness to pay (WTP) for land by nature-conservation organizations. We demonstrate that higher WTP increases land purchases considerably. However, the spatial pattern of land acquisition is fragmented, which may undermine its effectiveness from a restoration perspective.ConclusionsThe combination of these processes leads to land acquisitions for the NEN that do not meet the initially-stated policy objectives by far. In addition, the abolition of a land-trade organization supported by a land bank leads to more fragmented pattern of nature reserves.

Landscape level simulation of land use change

Land use changes are a result of decision making at the local level which is influenced by changes in the regional and global economy, demography, policies and other factors operating over a wide range of organisational levels and spatial scales. This chapter describes a methodology to integrate the demands for changes in land use as determined by global and national scale processes with local level conditions influencing land use conversions across the European Union. The approach enables an assessment of landscape level changes in land use and the analysis of policies specifically aimed at land use and landscape functioning. A baseline scenario is presented to illustrate the approach and results.