Spatial distribution of Buxus Blight and its relation with some Environmental factors (Case study: Khiboos Anjilsi Protected area)

In this recent years with the development of natural sciences, the importance of biodiversity is Revealed In different fields and the objectives of forest management are foccosed on biodiversity. So that nowadays conservation of biodiversity is considered as the most important issues in sustainable forest management. The importance of northern forests of Iran in aspect of conservation of genetic resources, and some plant species that are unique to this region is common clear fo all and And its vital role in many aspects such as economic, social, environmental balance, ecosystems stabilization and conservation has attracted the manager attention at the regional and local levels. One of the most important problems of that forests is Destruction Caused by natural and anthropogenic factors in recent decades, has faced them with a crisis situation. Lately, the Buxus Blight is encountered as an important problem in the northern forests. According to the importance of Buxus Hyrcana in aspect of biodiversity Iranian Forest managers are trying to identify its factors and spatial patterns.

The main goal of this study is investigation on spatial distribution of the Buxus Blight in relation to primary and secondary topography characteristics and distance from river and roads using terrain analysis and GIS.A 200×500 meters random systematic sampling network with 0.1 ha sample area was designed in GIS and applied on Khiboos & Anjilsi Forest protected Area. The location of diseased trees were registered using GPS in each sample and was imported to GIS. The digital elevation model (DEM) of the study area was generated using the interpolating of contour lines from 1:25000 topography map and the primary and secondary topography characteristics and distance from river and roads were produced using terrain analysis and GIS. The digital values of location of diseased trees were extracted on produced maps. The impact of selected factors on the tree crown dieback was assessed using relative effect (RE) method and principal component analysis (PCA).

The results showed that the north aspect, 400-600 meter mean sea level altitude, the 30-40 percent slop, the 0-50 meters distance from rivers, the 300-400 meters distance from roads, the shaded relief of 0.8-1, solar radiation of 0-250 and wetness of 17/5-20,were more effective on the Buxus Blight. The results of PCA analysis also showed that four factors of Aspect shaded relief wetness and distance from river with attending on four axes and 72 percent variances have been effective on Buxus Blight.

According to the results of this research it can be stated that damages caused by boxwood blight are heavily affected by some environmental factors such as light and humidity and landform factors because of receving of different amount of light and humidity have an important role in severity of that disease