Using the LANDIS model to evaluate forest harvesting and planting strategies under possible warming climates in Northeastern China. (Special Issue: Forest landscape modeling - approaches and applications.)

摘要

The Small Khingan Mountains in northeastern China provide most of the timber and wood products in the country. Evaluating the long-term effects of harvesting and planting strategies is important especially as the climate changes. In this study, we evaluated the effects of the projected climate warming on potential changes in species coverage (percent cover), area harvested (percentage of the study area) and species harvested, using the LANDIS model. Our evaluation was based on the harvest and planting plans specified in Natural Forest Protection Project (NFPP). Our simulated results show that the coverage of southern species, such as Korean pine (Pinus koraiensis) and ribbed birch (Betula costata), increased, whereas the coverage of northern species like larch (Larix gmelinii), Kingan fir (Abies nephrolepis), spruce (Picea koraiensis and Picea jezoensis) and Dahur birch (Betula davurica) decreased under the warming climate in the region. The species harvested primarily consisted of the southern species, especially deciduous species under the warming climate. The warming climate led to an 11.2% increase in area harvested compared to that under the current climate, when planting was not simulated. When planting was simulated, tradeoffs between planting and area harvested were complex. The area harvested only increased in places where moderate planting was implemented, and decreased in places with both low (<=5% area planted) and high (>=30%) planting percentage. This is because when the planting percentage is low, the rate of increase of harvestable species due to planting is lower than the rate of decrease of warming-declining species. When the planting percentage was high, the rate of increase of planted species was higher than the rate of colonization of warming-adapted deciduous species, and the planted species delayed the establishment of the warming-adaptable species that have short harvest rotations (due to lower harvestable ages). Our results suggest that the management strategy with planting area of 20% is the best among all the scenarios simulated. Under this warming climate, moderate planting area (e.g. 20%) increases the area harvested to ~43%, which is still less than that (58%) designated in the NFPP. These results have important implications for forest managers designing sustainable forest harvest and reforestation strategies for the landscape under the warming climate.