Title: Monitoring Protocols for the Ossipee and Waterboro Pine Barrens (2011)
Author: Tyler Bushell
Abstract: Fire suppression during the last 50-100 years has changed the composition and structure of northeastern pine barrens, a globally rare and fire-dependent natural community that provides habitat for numerous rare and declining Lepidopteran, plant and early successional/shrubland bird species. These changes have resulted in a number of deleterious effects to the natural community, including an increase in canopy cover and organic soils and the proliferation of tree species less tolerant of fire (such as red maple, white pine, red oak, aspen, and American beech). In some areas these species have invaded pine barrens to the exclusion of pitch pine and other constituent species. Additionally, in the absence of fire, fuel loads have in many areas reached a level that threatens nearby human development and could result in a catastrophic wildfire with an ecologically damaging intensity. As northeastern pine barrens shift away from their historic character the continued increase in hazardous fuels will be unabated and the composition of rare Lepidoptera and birds will shift, leaving some species more imperiled. In these scenarios, biodiversity—both in terms of natural communities and species—will be lost.
In response to these negative ecological changes the New Hampshire and Maine chapters of The Nature Conservancy (TNC) have set out to restore and/or maintain the northern pitch pine-scrub oak barrens (pine barrens) historically found at the Ossipee Pine Barrens (NH) and Waterboro Barrens (ME), as well as several other smaller sites. While managing the entire pine barrens system will include supporting viable wildlife populations and increasing herbaceous plant diversity, TNC is currently focusing on increasing the variability of the pine barrens seral stages to create a woody plant composition and community structure that is reminiscent of a pine barrens system historically influenced by fire. It is thought that promoting this structure and composition will support the constituent species dependant on it. After a pine barrens community structure and composition is present TNC will place emphasis on wildlife and herbaceous plant diversity objectives.
To manage the pine barrens and reduce fuel loads TNC has implemented a variety of ‘treatments’: timber harvest targeting fire-intolerant tree species, mowing of dense or senescent thickets of scrub oak, and prescribed burning. The ecological effects of these treatments are sometimes obvious but more often they are difficult to interpret. Because of this, TNC needs a systematic way to measure their progress towards meeting their ecological objectives (pg. 13). The purpose of this document is to assist TNC in carrying out the most cost and labor efficient approach to field-based data collection and data analysis.
I developed a set of monitoring protocols that yield quantitative information about five ecological attributes on treated lands, including:
The percent cover of exposed mineral soil
The average height of scrub oak
The percent cover of scrub oak
The relative abundance of pitch pine saplings vs. fire-intolerant saplings
The condition of fire-intolerant tree species
This quantitative information can be used to directly assess the progress land managers have made in their efforts to restore and/or manage the pine barrens as laid out in the TNC’s ecological objectives (pg. 13). These ecological objectives relate directly to the structure and composition of the pine barrens and 7 are a subset of the broader ecological objectives designed for the Ossipee Pine Barrens and the Waterboro Barrens, which include safeguarding populations of rare or declining wildlife (moth and bird species) and rare herbaceous plants.
Maintaining the pine barrens will rely on reoccurring fire, of which the frequency is unknown. The protocols described herein may produce ecological insight that helps The Nature Conservancy better understand the appropriate frequency of prescribed fire in their pine barrens.
In sections 7 of this document I outline a variety of analytical pathways and a sampling design alternative that, while using a common set of data collection methods, can be used to generate additional information about pine barrens ecology, including:
Tracking how ecological attributes (e.g., percent cover of mineral soil) change over time
Measuring an ecological attribute in different structural types (e.g., relative abundance of pitch pine saplings in areas of high and low canopy cover)
Analyzing the relationship of ecological attributes on one another (e.g., percent cover of scrub oak vs. pitch pine relative abundance)
Reporting the variation of an ecological attribute within a given area as ‘percent of sampling locations that meet the ecological objective’
The data collection protocols are accompanied by sections about sampling design, sample size, data storage and data analysis. The document is intended to inform the reader about the current ecosystem management at Ossipee and Waterboro and guide TNC through their monitoring program. These protocols were specifically designed with Ossipee and Waterboro in mind, but they may be applicable to other northeastern pine barrens.