EFForTS-LGraf: A landscape generator for creating smallholder-driven land-use mosaics.

Jan Salecker,Guy Pe´Er,Claudia Dislich,Katrin M Meyer,Kerstin Wiegand,Stephen P Aldrich

doi:10.1371/journal.pone.0222949

Abstract

Spatially-explicit simulation models are commonly used to study complex ecological and socio-economic research questions. Often these models depend on detailed input data, such as initial land-cover maps to set up model simulations. Here we present the landscape generator EFFortS-LGraf that provides artificially-generated land-use maps of agricultural landscapes shaped by small-scale farms. EFForTS-LGraf is a process-based landscape generator that explicitly incorporates the human dimension of land-use change. The model generates roads and villages that consist of smallholder farming households. These smallholders use different establishment strategies to create fields in their close vicinity. Crop types are distributed to these fields based on crop fractions and specialization levels. EFForTS-LGraf model parameters such as household area or field size frequency distributions can be derived from household surveys or geospatial data. This can be an advantage over the abstract parameters of neutral landscape generators. We tested the model using oil palm and rubber farming in Indonesia as a case study and validated the artificially-generated maps against classified satellite images. Our results show that EFForTS-LGraf is able to generate realistic land-cover maps with properties that lie within the boundaries of landscapes from classified satellite images. An applied simulation experiment on landscape-level effects of increasing household area and crop specialization revealed that larger households with higher specialization levels led to spatially more homogeneous and less scattered crop type distributions and reduced edge area proportion. Thus, EFForTS-LGraf can be applied both to generate maps as inputs for simulation modelling and as a stand-alone tool for specific landscape-scale analyses in the context of ecological-economic studies of smallholder farming systems.

Highlights

Land-use change was highlighted as one of the most important anthropogenic impacts on ecosystems [1]
Our results show that EFForTS-LGraf is able to generate realistic land-cover maps with properties that lie within the boundaries of landscapes from classified satellite images
This pattern was reversed for the output metric mean patch area, where the proportionagricultural-area had a larger effect on the mean patch area of field patches and the field-strategies-id had a larger effect on the mean patch area of ‘others’ class patches

Summary

Introduction

Land-use change was highlighted as one of the most important anthropogenic impacts on ecosystems [1]. [5, 6]) Environmental data, such as land-cover maps, can often not be obtained at the necessary level of detail. This problem is especially prevalent in tropical regions, where constant cloud coverage limits remote sensing data usability. In such cases, as well as for systematic research analyses, it may be necessary to artificially generate land-cover maps that approximate reality. As well as for systematic research analyses, it may be necessary to artificially generate land-cover maps that approximate reality For this purpose, landscape generators ( called landscape simulators) have been developed [7]. The option of producing a range of ( non-realistic) landscapes, e.g. by setting population density or field sizes to unrealistically high values, is an important tool for testing potential scenarios and improving the understanding of model processes

Objectives

Results

Conclusion