Short term grass bud response to high and low energy fires

Increasingly, land managers have attempted to use extreme prescribed fire as a method to address woody plant encroachment in savanna ecosystems. The effect that these fires have on herbaceous vegetation is poorly understood. We experimentally examined immediate (<24hr) bud response of two dominant graminoids, a C3 caespitose grass, Nassella leucotricha, and a C4 stoloniferous grass, Hilaria belangeri, following fires of varying energy (J/m2) in a semi-arid savanna in the Edwards Plateau ecoregion of Texas. Treatments included high- and low-energy fires determined by contrasting fuel loading and a no burn (control) treatment. Belowground axillary buds were counted and their activities classified to determine immediate effects of fire energy on bud activity, dormancy, and mortality. High-energy burns resulted in immediate mortality of N. leucotricha and H. belangeri buds (P < 0.05). Active buds decreased following high-energy and low-energy burns for both species (P < 0.05). In c...

越来越多的土地管理者尝试采用高强度计划火烧（prescribed fire）以应对稀树草原（savanna）生态系统中的木本植物侵占问题。目前学界对这类火烧对草本植被的影响尚缺乏充分认知。本研究于德克萨斯州爱德华兹高原生态区的半干旱稀树草原中，针对不同火能量（J/m²）的火烧后两种优势禾草类植物（graminoids）的即时（<24小时）芽响应开展了实验研究，供试物种分别为C3丛生型禾草白绒毛针茅（Nassella leucotricha）与C4匍匐茎型禾草贝氏希拉里草（Hilaria belangeri）。试验设置了由不同燃料载量确定的高、低能量火烧组与未火烧对照组，研究人员对地下腋芽（axillary buds）进行计数并对其活性进行分类，以明确火能量对芽活性、休眠状态及死亡率的即时影响。结果显示，高强度火烧会导致白绒毛针茅与贝氏希拉里草的芽出现即时死亡（P < 0.05）；两种禾草的活性芽数量均在高、低能量火烧后显著下降（P < 0.05）。在