Smithsonian Institution, Smithsonian Conservation Biology Institute, 1500 Remount Road, Front Royal, Virginia 22630, USA.
Ecol Appl. 2011 Oct;21(7):2425-44. doi: 10.1890/10-2383.1.
Land use and climate change have complex and interacting effects on naturally dynamic forest landscapes. To anticipate and adapt to these changes, it is necessary to understand their individual and aggregate impacts on forest growth and composition. We conducted a simulation experiment to evaluate regional forest change in Massachusetts, USA over the next 50 years (2010-2060). Our objective was to estimate, assuming a linear continuation of recent trends, the relative and interactive influence of continued growth and succession, climate change, forest conversion to developed uses, and timber harvest on live aboveground biomass (AGB) and tree species composition. We examined 20 years of land use records in relation to social and biophysical explanatory variables and used regression trees to create "probability-of-conversion" and "probability-of-harvest" zones. We incorporated this information into a spatially interactive forest landscape simulator to examine forest dynamics as they were affected by land use and climate change. We conducted simulations in a full-factorial design and found that continued forest growth and succession had the largest effect on AGB, increasing stores from 181.83 Tg to 309.56 Tg over 50 years. The increase varied from 49% to 112% depending on the ecoregion within the state. Compared to simulations with no climate or land use, forest conversion reduced gains in AGB by 23.18 Tg (or 18%) over 50 years. Timber harvests reduced gains in AGB by 5.23 Tg (4%). Climate change (temperature and precipitation) increased gains in AGB by 17.3 Tg (13.5%). Pinus strobus and Acer rubrum were ranked first and second, respectively, in terms of total AGB throughout all simulations. Climate change reinforced the dominance of those two species. Timber harvest reduced Quercus rubra from 10.8% to 9.4% of total AGB, but otherwise had little effect on composition. Forest conversion was generally indiscriminate in terms of species removal. Under the naive assumption that future land use patterns will resemble the recent past, we conclude that continued forest growth and recovery will be the dominant mechanism driving forest dynamics over the next 50 years, and that while climate change may enhance growth rates, this will be more than offset by land use, primarily forest conversion to developed uses.
土地利用和气候变化对自然动态森林景观具有复杂且相互作用的影响。为了预测和适应这些变化，有必要了解它们对森林生长和组成的单独和综合影响。我们进行了一项模拟实验，以评估美国马萨诸塞州未来 50 年（2010-2060 年）的区域森林变化。我们的目标是在假设近期趋势持续的情况下，估计持续增长和演替、气候变化、森林转换为开发用途以及木材采伐对活地上生物量（AGB）和树种组成的相对和交互影响。我们研究了 20 年的土地利用记录与社会和生物物理解释变量的关系，并使用回归树创建了“转换概率”和“采伐概率”区。我们将这些信息纳入一个空间互动的森林景观模拟器中，以检查森林动态如何受到土地利用和气候变化的影响。我们在完全因子设计中进行了模拟，并发现持续的森林生长和演替对 AGB 的影响最大，在 50 年内将储量从 181.83Tg 增加到 309.56Tg。根据该州内的生态区，增幅在 49%至 112%之间变化。与没有气候或土地利用的模拟相比，森林转换在 50 年内减少了 23.18Tg（或 18%）的 AGB 增益。木材采伐减少了 5.23Tg（4%）的 AGB 增益。气候变化（温度和降水）增加了 17.3Tg（13.5%）的 AGB 增益。在所有模拟中，Pinus strobus 和 Acer rubrum 在总 AGB 方面分别排名第一和第二。气候变化加强了这两个物种的优势。木材采伐将 Quercus rubra 的比例从总 AGB 的 10.8%降低到 9.4%，但对组成的影响不大。森林转换在物种去除方面通常是无差别的。在未来土地利用模式将类似于近期过去的假设下，我们得出结论，持续的森林增长和恢复将是未来 50 年推动森林动态的主要机制，尽管气候变化可能会提高生长速度，但这将被土地利用所抵消，主要是森林转换为开发用途。
