亚马逊的巨人:环境变化如何驱动大树的多样性模式?
Robson Borges de Lima1, Eric Bastos Görgens2, Diego Armando S da Silva3
1Laboratório de Manejo Florestal, Universidade do Estado do Amapá, Macapá, Brazil.
Global change biology
|June 30, 2023
概括
这项研究表明,亚马逊大树在高扰乱地区具有多样性,与所有树木不同,这些树在资源丰富的地区壮成长. 空间预测强调基于树的大小类别的独特多样性模式.
科学领域:
- 生态生态学 生态生态学
- 植物学 植物学
- 环境科学 环境科学
背景情况:
- 南美洲的历史树木多样性研究主要集中在树干直径≥2.5厘米或≥10厘米的树上.
- 这些研究发现,亚马逊西部和北部较潮湿的森林中物种多样性最高.
- 大树冠和新兴树木 (直径≥70厘米,胸高) 的多样性模式和驱动因素,尽管它们具有重要的生态作用,但仍未得到充分研究.
研究的目的:
- 调查和预测巴西亚马逊地区所有树木 (胸高直径[dbh]≥10厘米) 和非常大的树木 (dbh≥70厘米) 树木物种多样性的空间模式.
- 量化环境因素对不同大小类别和森林类型的树木多样性的影响.
- 突出大型树木与一般树木群体对比的多样性驱动因素.
主要方法:
- 利用机器学习方法分析了来自巴西亚马逊地区243个森林地块的数据,包括108,450棵树和2832个物种.
- 量化了环境因素在预测不同树木大小类别物种多样性的重要性.
- 在各种森林类型和生物地理区域中生成树木多样性模式的空间预测.
主要成果:
- 树木多样性,无论是大树还是所有树木,都与三个关键的环境因素有显著的关联,观察到区域和森林类型的变化.
- 与干扰 (例如闪电速率,风速) 和光的可用性 (光合作用活性辐射的部分) 相关的环境变量是大型树木多样性的主要驱动因素.
- 圭亚那盾和罗拉伊马地区的高地雨林表现出大量大型树木的多样性,而与资源相关的变量影响了整体树木多样性,伊梅里和马德拉北部的省份显示出高的一般物种多样性.
结论:
- 巴西亚马逊地区的树木物种多样性模式取决于大小,不同的环境驱动因素影响大树与一般树木种群.
- 干扰和光线的可用性对于大树木的多样性至关重要,而资源的可用性塑造了整体树木的多样性.
- 气候和地形稳定性,加上功能适应性,为物种多样性创造了最佳条件,需要大小类特定的保护策略.
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