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在火灾和稀释后,松树林的轨迹和转折点
Michala L Phillips1, Cara Lauria2, Tova Spector3
1U.S. Geological Survey, Pacific Island Ecosystems Research Center, Hawai'i Volcanoes National Park, Hawai'i, USA.
Global change biology
|February 11, 2024
概括
野火导致皮尼翁-树 (PJ) 森林的状态转移,导致草原占主导地位,并阻碍PJ再生. 稀释影响PJ生态系统,密集处理减少招募和生物覆盖.
科学领域:
- 生态学和生态恢复
- 林业和消防管理
- 生态系统的气候变化适应.
背景情况:
- 皮昂松 (PJ) 森林是山间西部地区的重要生态系统,面临着越来越多的野火频率和强度的威胁.
- 大规模的PJ死亡率和野火后的再生失败引起了人们对这些森林的长期生存能力和生态状况的担忧.
- 森林稀疏是一种管理策略,用于减轻野火风险和增强气候弹性,但其对PJ生态系统的影响尚未完全理解.
研究的目的:
- 调查野火和稀释处理对植被结构,微气候和 piñon-juniper 生态系统的再生动态的长期影响.
- 在经历野火和/或稀薄后大约20年,评估PJ林地生态状态的变化.
- 为促进PJ重建和保持生态系统弹性提供适应性管理策略的信息.
主要方法:
- 检查了大约20年前遭受野火和稀薄处理的地区的植被结构,微气候条件和松树-树再生.
- 烧毁,稀疏和完整的PJ社区之间的生态特征比较.
- 量化植物群落组成,PJ招募,间隙尺寸,生物土壤地覆盖,土壤水分,蒸汽压力赤字和光合作用活性辐射.
主要成果:
- 被烧毁的地区表现出显著的状态转变,其特点是草占主导地位,缺乏PJ招募,减少间隙尺寸,降低生物覆盖,降低土壤水分,增加光合作用活性辐射.
- 稀释处理导致了不同的植物群落,在完整和烧毁状态之间处于中间状态.
- 更强烈的稀释对PJ招募和晚期相继的生物地覆盖产生了负面影响,表明生态系统结构和功能受到更大的破坏.
结论:
- 野火可以在PJ生态系统中引发持续的状态转变,创造更干燥,更紧张的条件,在没有积极管理的情况下,有利于草而不是松松再生.
- 稀释强度会影响生态系统变化的程度,而密集的稀释可能会对PJ招募和土壤健康产生意想不到的后果.
- 管理行动,仔细考虑处理强度和目标,对于促进PJ重建和增强这些易受火灾和气候变化影响的脆弱生态系统的弹性至关重要.
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