摘要
以海南岛木麻黄海防林为研究对象,采用典型抽样调查方法,通过设立71个临时样,对其进行凋落物、土壤养分空间分布特征及其影响因素的研究。结果表明:1)木麻黄凋落物现存量较大,平均值和最大值分别为2.74 kg·m^(-2)和10.09 kg·m^(-2),凋落物分解缓慢,半分解凋落物质量平均占比为72.2%;2)土壤pH、有机质含量、铵态氮、有效磷和速效钾变化范围均较大,分别为4.83~9.51、0.30%~3.61%和2.26~49.43、2.92~342.55、3.36~111.93 mg·kg^(-2);3)有机质、速效钾和碱解氮整体较为缺乏,其中缺乏样地占比均>88.7%;有效磷则较为丰富,中等以上样地占78.8%;4)土壤养分与凋落物、土壤pH和气候区有明显的相关性,其中速效钾与凋落物厚度和半分解凋落物质量都呈极显著负相关,铵态氮则与之呈现显著正相关;铵态氮与pH呈显著负相关,有效磷则与其呈显著正相关;湿润区土壤有机质和铵态氮均显著高于半干旱区,但有效磷和速效钾则无显著差异。这说明土壤养分虽然与凋落物现存量具有一定的相关性,但大量积累的凋落物并没有明显改善滨海沙土贫瘠土壤的状况,其原因可能与快速生长的木麻黄对土壤养分的利用大于凋落物的归还、沙土淋溶,包括凋落物分解缓慢等多项因素。
Forest litter fall is the main carrier of material cycle and energy flow,and plays an important role in promoting nutrient cycle in forest ecosystem.Revealing the relationship between soil nutrient changes and litter falls is helpful to better understand the mechanism of carbon cycle,and nitrogen,phosphorus and potassium cycle in forest ecosystem.In this study,the spatial distribution characteristics of litter falls and soil nutrients,and impacting factors of soil nutrients in the coastal protection forests of Casuarina equisetifolia(CPFC)in Hainan Island were studied by setting 71 temporary sample plots,with typical sampling method.The results showed that 1)the litter fall accumulation of C.equisetifolia was large,with an average amount of 2.74 kg·m^(-2) and a maximum amount of 10.09 kg·m^(-2),respectively.The litter fall decomposition was slow,and the average mass ratio of semi-decomposed litter fall was 72.2%.2)Soil pH,organic matter content,ammonium nitrogen,available phosphorus and rapidly available potassium all varied greatly among different regions,with the ranges of 4.83-9.51,0.30%-3.61%,2.26-49.43,2.92-342.55 and 3.36-111.93 mg·kg^(-2),respectively.3)Organic matter,rapidly available potassium and alkali-hydrolyzable nitrogen in the CPFC were all deficient in general,in which sample plots under the nutrient deficiency accounted for more than 88.7%.The available phosphorus was more abundant,78.8%of sample plots were found in medium or above level.4)There were significant correlations between soil nutrients and litter falls,soil pH and climate regions.Rapidly available potassium was negatively correlated with the thickness of litter falls and the weight of semi-decomposed litter falls,while the ammonia nitrogen was positively correlated with the thickness of litter falls.There was a significant negative correlation between the ammonium nitrogen and pH,and a significant positive correlation between the available phosphorus and pH.The soil organic matter and ammonium nitrogen in humid region were signific
作者
杨彬
郝清玉
YANG Bin;HAO Qing-yu(Key Laboratory for Ecology of Tropical Islands,Ministry of Education,Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province,College of Life Sciences,Hainan Normal University,Haikou 571158,Hainan,China)
出处
《西北林学院学报》
CSCD
北大核心
2022年第3期9-15,36,共8页
Journal of Northwest Forestry University
基金
国家自然科学基金(31760202)。
关键词
木麻黄海防林
凋落物
土壤养分
影响因素
海南岛
Casuarina equisetifolia
litter fall
soil nutrient
impacting factor
Hainan Island
