The effects of drought and fire on seed and seedling dynamics in a tropical seasonal forest in Thailand
The effects of drought and fire on seed and seedling dynamics in a tropical seasonal forest in Thailand
复制标题
DOI：
10.1023/a:1020372401313
复制
发表时间：
2002-07-01
期刊：
影响因子：
1.7
通讯作者：
Nakashizuka, T
中科院分区：
文献类型：
--
作者：
Marod, D;Kutintara, U;Nakashizuka, T
对泰国西部Kantchanaburi的Mae Klong流域研究站6年(1992-1997年)的种子生产和苗木动态进行了研究，重点研究了干旱和火灾对热带季节天然林的影响。不同年份和不同树种的种子产量和出苗数量差异很大。大多数树种在1994年产生的种子很少，而在1995年和1996年产生的种子很多，特别是板栗。表现出最多播种习性的品种。苗木：Shorea、Dipterocpus alatus Roxb.在旱季结束时(4月下旬，第一次降雨之后，但土壤水分仍然很低)出苗，而大多数幼苗是在雨季开始时出苗。在1996年4月的一场大火扰乱了这片土地后，许多物种增加了他们的苗木出苗量，特别是白蜡梅。1年生以下树种的苗木在雨季的死亡率相对较低，而枫杨的苗木死亡率较高。所有苗木的平均存活率都很低(24.1%y(-1))，雨季和旱季的存活率分别为11.5%和6.1%(-1)。这表明不同物种对该热带季节森林群落的出苗季节和抗旱性有一定的适应性。树种的特性根据其在更新的早期阶段的特性进行分类；种子和/或苗库、再萌发和抗旱性。大多数物种通过重新萌发、种子库和/或苗木库来适应火灾和/或干旱，尽管少数主要出现在中生常绿森林中的物种对这些环境的适应程度较低。种子和幼苗阶段的种群差异可能有助于这些物种在这片物种丰富的干燥热带森林中共存。
Seed production and seedling dynamics were studied for 6 years (1992-1997) with particular emphasis on the effects of the drought and fire in a natural tropical seasonal forest at Mae Klong Watershed Research Station, Kantchanaburi, western Thailand. The number of seed produced and emerged seedlings varied greatly among years and species. Most tree species produced very few seeds in 1994 and many in 1995 and 1996, particularly, Shorea siamensis Miq. which displayed the most seeding habit. Some seedlings, Shorea, Dipterocarpus alatus Roxb., and Dipterocarpus turbinatus Gaertn. f., emerged at the end of the dry season (late April, after the first rain but when soils still have a low soil moisture content), while the majority of seedlings emerged at the beginning of the rainy season. After a fire disturbed the plot in April 1996, many species increased their seedling emergences, especially Berrya ammonilla. Seedlings of most species less than a year old showed a relatively low mortality in the rainy season, but those of Pterocarpus macrocarpus Kurz had high mortality. The mean survival rate for all seedling species in this forest was quite low (24.1% y(-1)), and different values existed for the rainy and the dry season (11.5, and 6.1% month(-1), respectively). This suggests that different species have adaptations related to the season of seedling emergence and resistance to drought in this tropical seasonal forest community. The traits of tree species are classified in terms of their traits in the early stages of regeneration; seed and/or seedling bank, resprouting, and drought resistance. Most species have adapted to fire and/or drought by resprouting, seed bank, and/or seedling bank, although the few species which occur mainly in mesic evergreen forests have less adapted to these environments. The demographic variations in seed and seedling stages may contribute to the coexistence of these species in this species-rich dry tropical forest.