The Ontario forest health data co-operative

The Canadian Forest Service, the Ontario Ministry of Natural Resources, and the Ontario Ministry of the Environment all conduct monitoring of forest health in Ontario. Among these agencies over 1500 permanent sample plots are monitored for purposes of assessing tree condition and/or site productivity. The data and length of record differ depending on the original intent of the plot system. However, a number of common variables are collected including basic tree measurements (tree height, stem diameter), mortality and site condition. Other variables collected at certain sites include crown condition, pest damage, ground vegetation, soils descriptions, and soils and foliage chemistry. A co-operative has been formed to compile this information from various sources and to make it more easily accessible. Information from these projects is available through the co-operative web site and can be extracted to report on forest health in a region of the province, or on an individual tree species. Information from these sources provide a picture of forest health in Ontario.

Genetic Structure of Cronartium ribicola Populations in Eastern Canada

ABSTRACT The genetic structure of populations of Cronartium ribicola was studied by sampling nine populations from five provinces in eastern Canada and generating DNA profiles using nine random amplified polymorphic DNA markers. Most of the total gene diversity (H(t) = 0.386) was present within populations (H(w) = 0.370), resulting in a low level of genetic differentiation among populations in northeastern North America (F(st) = 0.062). A hierarchical analysis of genetic structure using an analysis of molecular variance (AMOVA) revealed no statistically significant genetic differentiation among provinces or among regions. Yet, genetic differentiation among populations within regions or provinces was small (AMOVA phi(st) = 0.078) but statistically significant (P < 0.001) and was several orders of magnitude larger than differentiation among provinces. This is consistent with a scenario of subpopulations within a metapopulation, in which random drift following migration and new colonization are major evolutionary forces. A phenetic analysis using genetic distances revealed no apparent correlation between genetic distance and the province of origin of the populations. The hypothesis of isolation-by-distance in the eastern populations of C. ribicola was rejected by computing Mantel correlation coefficients between genetic and geographic distance matrices (P > 0.05). These results show that eastern Canadian provinces are part of the same white pine blister rust epidemiological unit. Nursery distribution systems are controlled provincially, with virtually no seedling movement among provinces; therefore, infected nursery material may not play an important role in the dissemination of this disease. Long-distance spore dispersal across provincial boundaries appears to be an epidemiologically important factor for this pathogen.