That is the case with Dutch elm disease and Chalara, both of which may have originated in Asia.During the 19th century, as global trade increased exponentially, so did the incidence of tree blights.
Our results suggest that the high incidence of hybrid trees in anthropogenic landscapes is attributed to a combination of introduction history, dispersal limitation, and reduced competition.
The growing incidence of new tree pest and disease epidemics, many of them with the potential to radically reshape our native woodlands and forests, is closely linked to a significant upsurge in global trade and transportation in recent decades.
The increase in abusive cutting of trees, incidence of conflict over natural resources and spread of invasive species were perceived as high in Bougouni by farmers and settled pastoralists.
We used Ceratocystidaceae fungi as an empirical system to explore the potential of metacommunity principles to explain the incidence of putative fungal tree pathogens in natural ecosystems.
The analysis of deviance of the logistic regression model of the total incidence of infection per tree across the course of the study indicated no significant difference in N. fuckeliana infection between pruned and unpruned trees (F1,167=0.24, p=0.62; Figure 3a).
Respondents in Bougouni were more likely to observe an increase in incidence of uncontrolled bush fire, abusive cutting of trees, spread of invasive species and incidence of conflict over natural resources than those in Koutiala.
The ever-growing urbanization of the region has led to an increase in the incidence of intracity flooding as tree-lined meadows and other catchments give way to lawns and parking lots that cannot hold rainwater runoff.
Despite a high incidence of heart-rot, live-tree and total forest (minus mineral soil) C stocks (348 ± 155 and 455 ± 156 Mg C ha−1, respectively) in uncut old-growth ITR stands were within the range of regional averages for old-growth forests in the Pacific Northwest (US) and coastal cedar and hemlocks forests of BC.
Each interviewee was first asked about the trend of different elements of natural resource management (e.g. incidence of uncontrolled bush fire, abusive tree cutting, primary productivity of vegetation, species richness, availability of water) in the community over the past 30 years.
