Resilience of soil nutrient availability and organic matter decomposition to hurricane impact in a tropical dry forest ecosystem
Resilience of soil nutrient availability and organic matter decomposition to hurricane impact in a tropical dry forest ecosystem
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热带干燥森林生态系统中土壤养分有效性和有机质分解对飓风影响的恢复能力
DOI：
10.1016/j.foreco.2017.08.041
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发表时间：
2017
影响因子：
3.7
通讯作者：
Claudia Urquijo
中科院分区：
文献类型：
--
作者：
M. Gavito;A. Sandoval;Karem del Castillo;Daniel Cohen;María Elena Colarte;F. Mora;Angélica Santibáñez;I. Siddique;Claudia Urquijo
飓风乔瓦和帕特里夏是近代史上第一批登陆墨西哥太平洋沿岸热带干燥森林生态系统的飓风。我们研究了土壤N、P有效性和有机质分解对这两场飓风对该地区牧场、演替农田和老森林的影响的恢复能力。我们通过比较每次飓风前后的测量结果来评估抵抗力。我们还检查了时间趋势，以测试在两次飓风之间的四年期间是否恢复了对Jova不具抵抗力的变量。我们认为那些要么表现出抗药性，要么没有抗药性但显示复苏的变量是有弹性的。我们假设，在两次飓风过后，由于高质量分解材料的大量结合，特别是在植被较多的土地覆盖下，分解和土壤养分的有效性将很快增加，并在几年内恢复到飓风前的值。我们的测试表明，大多数测量的变量对这两个飓风都没有抵抗力，而且飓风之间的变化方向或大小有时会有所不同。乔瓦飓风过后，土壤有效氮增加了四倍，帕特里夏飓风过后，土壤有效氮增加了两倍。土壤速效磷在整个生育期内变化不大。总的凋落物储量抵抗飓风的侵袭，只有土地覆盖不同，而凋落物C、N和P的储量随着飓风的变化而变化，并在接下来的三年里在所有土地覆盖中变得更加相似。在乔瓦飓风过后的几个月里，土壤氮素峰值导致落叶所产生的凋落物中的C：N和N：P比率下降。然而，这一下降是在乔瓦飓风过后仅两年就测量到的，总累积垃圾数量。乔瓦飓风过后，当地近期凋落物的腐解率下降，帕特里夏飓风过后，腐解率上升，但在乔瓦飓风过后两年内恢复。作为对照的所有地点的标准材料的分解显示出减少的趋势，这表明在飓风乔瓦之后分解者的活动继续减少。总体而言，土地覆盖之间的差异比我们预期的要小，而且它们在大多数变量上的年际波动令人惊讶地相似。我们得出的结论是，在乔瓦飓风和帕特里夏飓风之间的四年内，养分的可获得性和分解总体上没有抵抗，但恢复到飓风前的水平。因此，这些生态系统功能似乎具有弹性，至少对乔瓦飓风是如此。
Hurricanes Jova and Patricia were the first hurricanes in recent history to make landfall on the tropical dry forest ecosystem of the Pacific coast of Mexico. We examined the resilience of soil N and P availability and organic matter decomposition to the effects of both hurricanes in pastures, successional fields and old-growth forests of this region. We evaluated resistance by comparing measurements made before and after each hurricane. We also examined temporal trends to test if variables non-resistant to Jova recovered during the four-year period between both hurricanes. We considered resilient those variables that either showed resistance or were not resistant but showed recovery. We hypothesized that decomposition and soil nutrient availability would increase shortly due to the massive incorporation of high-quality decomposing materials after both hurricanes, especially under land covers with more woody vegetation, and return to pre-hurricane values within a couple of years. Our tests showed that most variables measured were not resistant to either hurricane and that the direction or magnitude of change sometimes differed between hurricanes. There was a fourfold increase in soil available N after hurricane Jova and a twofold increase after hurricane Patricia. Soil available P changed little over the entire period. Total litter stocks resisted hurricane passage and differed only among land covers whereas litter C, N and P stocks changed with the hurricane and became more similar in all land covers over the following three years. The soil N peak caused a decrease in the C:N and N:P ratios in the litter produced from the leaf flush some months after Hurricane Jova. This decrease was measured, however, only two years after hurricane Jova in total accumulated litter. Decomposition rates of local recent litter decreased after hurricane Jova and increased after hurricane Patricia but recovered within two years after hurricane Jova. Decomposition of a standard material in all sites, used as a control, showed a decreasing trend suggesting a continuous reduction in decomposer activity after hurricane Jova. Overall there were smaller differences among land covers than we had expected and their inter-annual fluctuations in most variables were surprisingly similar. We conclude that nutrient availability and decomposition were in general not resistant but returned to pre-hurricane levels within the four years between hurricane Jova and hurricane Patricia. Therefore, these ecosystem functions seemed resilient, at least to hurricane Jova.