Date of Award

2016

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Natural Resources

First Advisor

Allan M. Strong

Abstract

Agricultural landscapes provide our society with many benefits. While food production is the primary role of these landscapes, sociocultural and ecological benefits are also provided. However, the full scope of benefits that we obtain from agricultural landscapes are not always taken into account, and with the intensification of agricultural activities, more complex multifunctional landscapes are converted into simpler and less-functional landscapes. I used a heterogeneous agricultural landscape, the Champlain Valley of Vermont, as a case study to examine the interactions between landscape structure and the provision of landscape functions and services.

I analyzed sociocultural and production functions indices obtained via standardized landowner surveys, and ecological function indices collected in the field for 51 plots. Plots were clustered into landscape composition categories (forest, mixed and agriculture), and configuration categories (simple and complex).

I identified a tradeoff between the production and ecological function in agricultural landscapes. When a rural landscape was managed for intensive agricultural production, ecological benefits decreased. Landscapes with diversified land use/land cover and heterogeneously distributed elements returned the greatest number of benefits. Agricultural areas that comprise between 30 and 45% of the landscape can prevent the loss of ecological benefits while retaining high production.

I evaluated the importance of treed habitats in agricultural landscapes in maintaining biodiversity. I related landscape metrics to ecological function indices obtained from fine-grained land use/land cover maps. Metrics obtained from fine-grained maps more accurately predicted the abundance of edge tolerant birds than those obtained from coarse grained maps.

I also explored the importance of small treed landscape elements for common breeding birds and evaluated the convenience of monitoring nests comparing temperature loggers to direct observations. More heterogeneous landscapes, rich in small treed elements, supported a greater density of nests. Nests located on small treed elements in agricultural landscapes were as successful as nests located in large landscape elements.

These analyses deepen our knowledge about the relationship between landscape structure and function, facilitating the evaluation of the functionality of heterogeneous agricultural landscapes.

Language

en

Number of Pages

172 p.