Treesearch

White pine blister rust disease, caused by the introduced pathogen Cronartium ribicola, has severely disrupted five-needled pine ecosystems in North America. A 100-year effort to manage this disease was predicated in part on the premise that the pathogen utilizes only species of Ribes (Grossulariaceae) as alternate hosts on this continent. The current study presents the first conclusive demonstration that some species in the family Orobanchaceae (Pedicularis racemosa and Castilleja miniata) are functioning as alternate hosts in a natural ecosystem of North America. This finding has...

Maine’s initial Greenhouse Gas (GHG) estimates of the Land Use Change and Forestry (LUCF) sub-accounts predicted that this account supplied 15 percent of the net emissions in 2000. The magnitude and direction of this estimate ran counter to internal assumptions and the recently published analysis on multiple and positive forest inventory changes for the period of 1995 to 2002. The major cause was the simple assignment and linkage of a forest soil’s organic carbon level to a single specific forest type group. Carbon emissions were predicted as a result of changes in the forest type distribut...

Integration of biological and physical concepts is necessary to understand and conserve the ecological integrity of river systems. Past attempts at integration have often focused at relatively small scales and on mechanistic models that may not capture the complexity of natural systems leaving substantial uncertainty about ecological responses to management actions. Two solutions have been proposed to guide management in the face of that uncertainty: the use of “natural variability” in key environmental patterns, processes, or disturbance as a reference; and the retention of some areas as...

The FIREMON Cover/Frequency (CF) method is used to assess changes in plant species cover and frequency for a macroplot. This method uses multiple quadrats to sample within-plot variation and quantify statistically valid changes in plant species cover, height, and frequency over time. Because it is difficult to estimate cover in quadrats for larger plants, this method is primarily suited for grasses, forbs, and shrubs less than 3 ft (1 m) in height. Quadrats are placed systematically along randomly located transects. Cover is assessed by visually estimating the percent of a quadrat occupied...

The FIREMON Density (DE) method is used to assess changes in plant species density and height for a macroplot. This method uses multiple quadrats and belt transects (transects having a width) to sample within plot variation and quantify statistically valid changes in plant species density and height over time. Herbaceous plant species are sampled with quadrats while shrubs and trees are sampled with belt transects. Quadrats for sampling herbaceous plants are placed systematically along randomly located transects. Belt transects for sampling shrub and tree density use the same randomly...

The FIREMON Line Intercept (LI) method is used to assess changes in plant species cover for a macroplot. This method uses multiple line transects to sample within plot variation and quantify statistically valid changes in plant species cover and height over time. This method is suited for most forest and rangeland communities, but is especially useful for sampling shrub cover greater than 3 ft (1 m) tall, because it is difficult to ocularly estimate the cover of tall shrubs. The LI method can be used in conjunction with cover-frequency (CF) transects when vegetation over 3 ft (1 m) exists....

The FIREMON Rare Species (RS) method is used to assess changes in uncommon, perennial plant species when other monitoring methods are not effective. This method monitors individual plants and statistically quantifies changes in plant survivorship, growth, and reproduction over time. Plants are spatially located using distance along and from a permanent baseline, and individual plants are marked using a permanent tag. Data are collected for status (living or dead), stage (seedling, nonreproductive, or reproductive), size (height and diameter), and reproductive effort (number of flowers and...

Landscape Assessment primarily addresses the need to identify and quantify fire effects over large areas, at times involving many burns. In contrast to individual case studies, the ability to compare results is emphasized along with the capacity to aggregate information across broad regions and over time. Results show the spatial heterogeneity of burns and how fire interacts with vegetation and topography. The quantity measured and mapped is “burn severity,” defined here as a scaled index gauging the magnitude of ecological change caused by fire. In the process, two methodologies are...

The Tree Data (TD) methods are used to sample individual live and dead trees on a fixed-area plot to estimate tree density, size, and age class distributions before and after fire in order to assess tree survival and mortality rates. This method can also be used to sample individual shrubs if they are over 4.5 ft tall. When trees are larger than the user-specified breakpoint diameter the following are recorded: diameter at breast height, height, age, growth rate, crown length, insect/disease/abiotic damage, crown scorch height, and bole char height. Trees less than breakpoint diameter and...

The FIREMON Species Composition (SC) method is used to provide ocular estimates of cover and height measurements for plant species on a macroplot. The SC method provides plant species composition and coverage estimates to describe a stand or plant community and can be used to document changes over time. It is suited for a wide variety of vegetation types and is especially useful in plant communities with tall shrubs or trees. The method is relatively fast and efficient to conduct in the field and facilitates sampling many sites over large areas using few examiners. The SC method does not...