Co-evolution of landscape patterns and agricultural intensification: an example of dairy farming in a traditional Dutch landscape.

摘要

The intensification of agricultural production strongly affects the characteristics of traditional rural landscapes. Yet, the complexity of these landscapes also puts constraints on intensification. This interrelationship leads to the hypothesis that the degree of intensification and locality are interdependent. Feedbacks between landscape and intensification often go unnoticed, while such a coupling would argue for spatial explicit studies with a co-evolutionary perspective. In this study, we localized and quantified interactions between landscape patterns and agricultural intensification for dairy farming systems in a traditional Dutch rural landscape. First, a conceptual diagram was made that maps causal interactions between landscape patterns and production intensity. This conceptual diagram was converted to spatial explicit descriptors of landscape patterns, such as hedge density, field size, clay content, ground water hydrology and spatial explicit descriptors of management such as hedgerow change, field aggregation, field grazing days and fertilizer application. Next, these landscape patterns and management descriptors were linked to the current production intensity of farms such as total farm milk yield, milk yield per cow and milk yield per hectare. These descriptors were tested for interrelations by applying two-sample Kolmogorov-Smirnov tests. We found that a higher milk production was significantly linked to larger fields, fewer hedgerows, fewer grazing days, higher use of N-fertilizer and a decrease of nutrient cycling. Furthermore, production intensity was found to differ with the landscape pattern of clay content and groundwater hydrology. On top of this landscape template, man-made patterns of field sizes and hedgerows from before 1930 are still visible in the current differences of milk production intensity. Current farm management was found to have relations with the hedgerows, field size, clay content and groundwater hydrology. These relations hint at a co-evolution of landscape pattern and agricultural intensification. Interestingly, the largest differences between descriptors of landscape pattern and intensity were found for similar values of clay content, groundwater hydrology and fertilizer use. We speculate that these similar values indicate the existence of tipping points for diverging trajectories of intensification. Identification of such tipping points has implications for policies that deal with the future dynamics of rural landscapes.