The Potential Distribution of Tree Species in Three Periods of Time under a Climate Change Scenario

Species distribution models have become some of the most important tools for assessment of impact of climatic change, impact of human activity and for the detection of failure in silvicultural or conservation management plans. In this study, we modeled the potential distribution of 13 tree species of temperate forests distributed in the Mexican state Durango in the Sierra Madre Occidental, for three periods of time. Models were constructed for each period of time using 19 climate variables from the MaxEnt (Maximum Entropy algorithm) modelling algorithm. Those constructed for the future used a severe climate change scenario. When comparing the potential areas of the periods, some species such as Pinus durangensis (Martínez), Pinus teocote (Schiede ex Schltdl. & Cham.) and Quercus crassifolia (Bonpl.) showed no drastic changes. Rather, the models projected a slight reduction, displacement or fragmentation in the potential area of Pinus arizonica (Engelm.), P. cembroides (Zucc), P. engelmanni (Carr), P. leiophylla (Schl), Quercus arizonica (Sarg), Q. magnolifolia (Née) and Q. sideroxila (Humb. & Bonpl.) in the future period. Thus, establishing conservation and reforestation strategies in the medium and long term could guarantee a wide distribution of these species in the future.

Risk evaluation of the climatic change impact on secondary Norway spruce stands as exemplified by the Ktiny Training Forest Enterprise

The paper proposes a method of assessing the potential risks of the future development of stands in relation to a climatic change. To assess risks of the future development of a stand simple point scales have been worked up based on primary properties of a site and a stand according to data of the forest management plan (FMP). In assessing the health condition, the risk of damage to stands by Armillaria sp. in the felling age was evaluated on the basis of a present attack by Armillaria sp. and also defoliation of the crown primary structure assessed during a simple field examination. The evaluation was carried out in the region of the Křtiny Training Forest Enterprise (TFE) Masarykův les, ranger district Proklest, in 2002. The study was conducted in <br />118 Norway spruce stands aged more than 20 years. The majority of evaluated stands ranked among the category of high and medium risk from the viewpoint of site and stand risks and among the category of high Armillaria sp. attack. &nbsp; &nbsp;