Gómez-Mendoza Leticia, Arriaga Laura
Instituto de Geografía, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, D.F. C.P. 14510, México.
Conserv Biol. 2007 Dec;21(6):1545-55. doi: 10.1111/j.1523-1739.2007.00814.x.
We examined the vulnerability of 34 species of oaks (Quercus) and pines (Pinus) to the effects of global climate change in Mexico. We regionalized the HadCM2 model of climate change with local climatic data (mean annual temperature and rainfall) and downscaled the model with the inverse distance-weighted method. Databases of herbaria specimens, genetic algorithms (GARP), and digital covers of biophysical variables that affect oaks and pines were used to project geographic distributions of the species under a severe and conservative scenario of climate change for the year 2050. Starting with the current average temperature of 20.2 degrees C and average precipitation of 793 mm, under the severe warming scenario mean temperature and precipitation changed to 22.7 degrees C and 660 mm, respectively, in 2050. For the conservative warming scenario, these variables shifted to 21.8 degrees C and 721 mm. Responses to the different scenarios of climate change were predicted to be species-specific and related to each species climate affinity. The current geographic distribution of oaks and pines decreased 7-48% and 0.2-64%, respectively. The more vulnerable pines were Pinus rudis, P. chihuahuana, P. oocarpa, and P. culminicola, and the most vulnerable oaks were Quercus crispipilis, Q. peduncularis, Q. acutifolia, and Q. sideroxyla. In addition to habitat conservation, we think sensitive pine and oak species should be looked at more closely to define ex situ strategies (i.e., seed preservation in germplasm banks) for their long-term conservation. Modeling climatic-change scenarios is important to the development of conservation strategies.
我们研究了墨西哥34种栎属（Quercus）和松属（Pinus）植物对全球气候变化影响的脆弱性。我们利用当地气候数据（年平均温度和降雨量）对HadCM2气候变化模型进行区域化处理，并采用反距离加权法对该模型进行降尺度处理。利用植物标本数据库、遗传算法（GARP）以及影响栎属和松属植物的生物物理变量数字覆盖图，来预测这些物种在2050年严峻且保守的气候变化情景下的地理分布。从当前平均温度20.2摄氏度和平均降水量793毫米开始，在严峻变暖情景下，到2050年平均温度和降水量分别变为22.7摄氏度和660毫米。在保守变暖情景下，这些变量变为21.8摄氏度和721毫米。预计对不同气候变化情景的响应具有物种特异性，且与每个物种的气候亲和力有关。栎属和松属植物当前的地理分布分别减少了7 - 48%和0.2 - 64%。较为脆弱的松树品种有粗枝松（Pinus rudis）、奇瓦瓦松（P. chihuahuana）、卵果松（P. oocarpa）和顶生松（P. culminicola），而最脆弱的栎树品种有皱叶栎（Quercus crispipilis）、有柄栎（Q. peduncularis）、尖叶栎（Q. acutifolia）和铁橡栎（Q. sideroxyla）。除了栖息地保护外，我们认为对于敏感的松树和栎树物种，应更深入地研究，以确定其异地保护策略（如在种质库中保存种子），实现长期保护。模拟气候变化情景对制定保护策略至关重要。
