Abstract:
Habitat fragmentation has been widely studied in the biological literature and
is considered a primary threat to biodiversity. However, there has been little research
on land-use policies to reduce fragmentation. This dissertation focuses on two major
research issues related to fragmentation policies. First, I develop an analytical model
to analyze the optimal conservation strategy on a landscape with habitat
fragmentation effects. Second, I develop an empirical methodology to quantify the
economic costs of reducing fragmentation through the use of incentive-based land-use
policies.
A theoretical model of land use is developed to analyze the spatial
configuration of landscapes when land quality is spatially heterogeneous and wildlife
habitat is fragmented and socially valuable. When urban development is the primary
cause of fragmentation, I show how spatial heterogeneity in amenities and household
neighbor preferences affect the optimal landscape and the design of efficient land-use
policies. When agriculture is the primary cause of fragmentation, I derive optimal
conservation strategies for reducing fragmentation. I show that reforestation efforts should be targeted to the most fragmented landscapes with an aggregate share of
forest equal to a threshold, defined by the ratio of the opportunity cost of conversion
to the social value of core forest.
A parcel-level econometric model of land-use change is developed and
integrated with spatially-explicit landscape simulations to predict the empirical
distribution of fragmentation outcomes under given market conditions and policy
scenarios. I examine the effects of alternative policy designs on various measures of
fragmentation and then quantify the costs of achieving spatial outcomes. I find that
the costs of reducing forest fragmentation vary greatly with initial landscape
conditions and that a simple uniform subsidy appears to perform well relative to more
complicated spatially-targeted policies. In addition, my results suggest that initial
landscape conditions, rather than the policy approach, should be the foremost
consideration for wildlife managers deciding how to allocate a limited budget to
conservation efforts.
