Impact of an agri-environmental scheme on landscape patterns

Abstract

Human culture and policy play an important role in structuring landscape patterns. Agriculture is an example of a land use practice that has altered landscape patterns worldwide and agricultural intensification coupled with broad patterns in land use change have resulted in decreased cover of native plant communities and a loss in biodiversity. The Conservation Reserve Program (CRP) was initially developed to address large agricultural surpluses by transitioning highly erodible cropland into conservation-related perennial cover types. Research has demonstrated that this program can help restore ecological processes across landscapes. However, this program can also impact landscape patterns across multiple spatial scales, though its direct influence to these patterns is poorly understood. To understand the contribution of currently enrolled CRP lands to broadscale landscape patterns, we used FRAGSTATS and non-metric multidimensional scaling (NMDS) to assess how patch- and class- scale landscape patterns change in relation to grasslands across the state of Oklahoma with the presence and theoretical absence of CRP. Furthermore, we determined how these patterns vary across three spatial extents: the statewide, the Environmental Protection Agency (EPA) defined ecoregions, and the county extents within Oklahoma. Though impacts at the statewide extent were minimal, NMDS results indicated shifts in landscape patterns across ecoregions and counties that were primarily associated with increases in effective mesh size and largest patch index. Our results indicate that CRP can help maintain complexity of the grassland matrix through improving connectivity. However, the direct impacts of CRP on landscape patterns is dynamic across spatial scales and these effects influence the overall perceived impact of CRP to grassland patterns.