Factors Affecting the Ecological Legacy of Unsalvaged Post-mountain Pine Beetle Stands


Book Description

"The overall objective of this research is to obtain information that will help managers determine what ecological legacies exist in post-beetle forests. The research is designed to 1) provide information about the ecological value of unsalvaged beetle-infested stands; 2) provide understanding of how ecological legacies may vary; and 3) generate information that would contribute to the development of decision support tools for improving ecological integrity in the post-beetle landscape."--Document.







Historic Influence of the Mountain Pine Beetle on Stand Dynamics in Canada's Rocky Mountain Parks


Book Description

The Canadian government announced the Mountain Pine Beetle Initiative (MPBI) in 2002 to address the socio-economic and ecological consequences of an epidemic of mountain pine beetle (Dendroctonus ponderosae Hopkins). The objective of this study was to establish baseline information on the ecological characteristics that occur at different stages of succession, resulting from mountain pine beetle disturbance at different time intervals. Key issues addressed by this study were: the post-beetle ecological character of stands; the ecological legacies that should be sought post-beetle; maintenance of ecological integrity in beetle-damaged landscapes; and the impacts of beetles on regeneration. This paper presents a study of stand conditions following two historic mountain pine beetle outbreaks events in the 1940s and 1980s. The study quantified structural and species composition of stands at different stages of succession (25 years and 65 years), and quantified the differences that occur in forest development between stands with and without disturbance by the beetle. It concludes with several recommendations for management of post-disturbance landscapes.










Mountain Pine Beetle-killed Trees as Snags in Black Hills Ponderosa Pine Stands


Book Description

Mountain pine beetle-killed ponderosa pine trees in three stands of different stocking levels near Bear Mountain in the Black Hills National Forest were surveyed over a 5-year period to determine how long they persisted as unbroken snags. Rate of breakage varied during the first 5 years after MPB infestation: only one tree broke during the first 2 years in the three stands; breakage increased during the third year; the highest percentage of snags broke during the fourth year; and 10% to 14% broke in the fifth year. Cumulatively, snag breakage was 76%, 91%, and 95% in a GSL 80/90, GSL 100/110, and unmanaged stand, respectively. On average, 56% of the snags broke below 25 ft. The rate and height of breakage in mountain pine beetle-killed trees indicates that they are unlikely to persist as suitable snags for more than 5 to 10 years after infestation.







Mountain Pine Beetle Attack in Ponderosa Pine: Comparing Methods for Rating Susceptibility


Book Description

Two empirical methods for rating susceptibility of mountain pine beetle attack in ponderosa pine were evaluated. The methods were compared to stand data modeled to objectively rate each sampled stand for susceptibly to bark-beetle attack. Data on bark-beetle attacks, from a survey of 45 sites throughout the Colorado Plateau, were modeled using logistic regression to estimate the probability of attack on individual trees from tree and stand variables. The logistic model allowed flexibility to easily scale results up to a stand level for comparison to the empirical methods. The empirical method, developed by Munson and Anhold, most closely correlated to the logistic regression results. However, the Munson/Anhold method rated all 45 study sites as either moderately or highly susceptible to bark-beetle attack, which raises concern about its lack of sensitivity. Future work on evaluating risk of bark-beetle impact should consider more than stand characteristics.