Vegetation Monitoring to Guide Management Decisions in Miami's Urban Pine Rockland Preserves

摘要

We developed a monitoring program to assess the health of urban fragments of pine rockland, a globally critically imperiled, fire-dependent plant community, in order to provide feedback for adaptive land management. Our results showed negative effects of fire exclusion, including low native herb and grass cover, excessive leaf litter accumulation, and high densities of native trees in most of the twelve preserves sampled. We provide quantitative evidence of the need for instituting regular prescribed fires to Miami-Dade County's pine rockland preserves, and lend support to the idea that, in degraded urban fragments, manual hardwood reduction is sometimes a required first step toward achieving maintenance conditions. We demonstrate that simple actions like measuring litter depth or visually estimating hardwood cover can be utilized by preserve managers as a quick, inexpensive way to prioritize hardwood reduction and burn scheduling. Our results serve as a case study for other urban forest fragments with similar issues.