TY - RPRT
T1 - Spatial-temporal modeling of forest gaps generated by colonization from below- and above-ground beetle species
AU - Zhu, J.
AU - Rasmussen, Jakob Gulddahl
AU - Møller, Jesper
AU - Aukema, B.H.
AU - Raffa, K.F.
PY - 2006
Y1 - 2006
N2 - Studies of forest declines are important, because they both reduce timber production and aect successional trajectories of landscapes and ecosystems. Of partic-
ular interest is the decline of red pines which is characterized by expanding areas
of dead and chlorotic trees in plantations throughout the Great Lakes Region.
Here we examine the impact of two bark beetle groups, namely red turpentine
beetles and pine engraver bark beetles, on tree mortality and the subsequent gap
formation over time in a plantation in Wisconsin. We construct spatial-temporal
statistical models that quantify the relations among red turpentine beetle coloniza-
tion, pine engraver bark beetle colonization, and mortality of red pine trees, while
accounting for correlation across space and over time. For statistical inference,
we adopt a Bayesian hierarchical model and devise Markov chain Monte Carlo
algorithms for obtaining the posterior distributions of model parameters as well
as posterior predictive distributions. Our data analysis results suggest that red
turpentine beetle colonization is associated with higher likelihood of pine engraver
bark beetle colonization and pine engraver bark beetle colonization is associated
with higher likelihood of red pine tree mortality, whereas there is no direct associa-
tion between red turpentine beetle colonization and red pine tree mortality. There
is strong evidence that red turpentine beetle colonization does not kill a red pine
tree directly, but rather predisposes the tree to subsequent colonization by pine
engraver bark beetles. The evidence is also strong that pine engraver bark beetles
are the ultimate mortality agents of red pine trees.
AB - Studies of forest declines are important, because they both reduce timber production and aect successional trajectories of landscapes and ecosystems. Of partic-
ular interest is the decline of red pines which is characterized by expanding areas
of dead and chlorotic trees in plantations throughout the Great Lakes Region.
Here we examine the impact of two bark beetle groups, namely red turpentine
beetles and pine engraver bark beetles, on tree mortality and the subsequent gap
formation over time in a plantation in Wisconsin. We construct spatial-temporal
statistical models that quantify the relations among red turpentine beetle coloniza-
tion, pine engraver bark beetle colonization, and mortality of red pine trees, while
accounting for correlation across space and over time. For statistical inference,
we adopt a Bayesian hierarchical model and devise Markov chain Monte Carlo
algorithms for obtaining the posterior distributions of model parameters as well
as posterior predictive distributions. Our data analysis results suggest that red
turpentine beetle colonization is associated with higher likelihood of pine engraver
bark beetle colonization and pine engraver bark beetle colonization is associated
with higher likelihood of red pine tree mortality, whereas there is no direct associa-
tion between red turpentine beetle colonization and red pine tree mortality. There
is strong evidence that red turpentine beetle colonization does not kill a red pine
tree directly, but rather predisposes the tree to subsequent colonization by pine
engraver bark beetles. The evidence is also strong that pine engraver bark beetles
are the ultimate mortality agents of red pine trees.
M3 - Report
T3 - Research Report Series
BT - Spatial-temporal modeling of forest gaps generated by colonization from below- and above-ground beetle species
PB - Department of Mathematical Sciences, Aalborg University
ER -