鼎湖山不同植被类型下土壤微生物养分的矿化

MINERALIZATION OF SOIL MICROBIAL C. N. P AND K IN DIFFERENT VEGETATIONS TYPES AT DINGHUSHAN BIOSPHERE RESERVE

本研究测定了鼎湖山５种主要植被类型下土壤微生物养分的矿化值，结果表明：同一植被类型下，土壤微生物３种养分元素（氮、磷、钾）的矿化值大小不一，其顺序是：矿化氮（铵态氮十硝态氮）＞矿化钾＞矿化磷。同一种养分元素，不同植被类型下的矿化也有较大差异。５种植被类型下土壤微生物氮、磷、钾的矿化值范围分别为：２０．２４－３３．３６、２．０１－３．８６和８．８８－１８．３５ｍｇ／ｋｇ（干土）。土壤微生物氮的矿化与土壤微生物生物量呈显著正相关，磷、钾的矿化与土壤微生物生物量无相关关系。不同植被类型下土壤微生物库养分贮量各不相同。碳、氮、磷和钾的贮量范围分别为：７０２．９４－１１５０．５８、９３．７２－１５５．５３、１０．９５－２０．２７和３４．０３－７０．３５ｋｇ／ｈａ，其平均贮量为：９２４．１５±１９５．７３，１１７．２７±２５．１５．０８±３．９５和５０．１４±１３．２９ｋｇ／ｈａ，分别占土壤库中有机碳、全氮、全磷和全钾的３．００±１．１３、５．３４±１．５７、１．７１±０．５７和０、６±０．２２％。５种植被类型中，季风常绿阔叶林的土壤微生物养分固定及其供应能力最强。

The mineralization of soil microbial N. P and K varied withvegctation types. ranging from 20.24- 33.36. 2.01- 3.86 and 888- 1835mgkg dry soil. resoectively. The amount of nitrogen mineralized from soil microbes wasclosely reiated to the biomass-C. The regression equation was y=0.3761×+4 8455. r=0.5519￣* (n=60). The total C. N. P and K in soil microbial pool were 702 94- 1150 58. 93 72- 15553. 10.95- 20.27 and 34.03- 7035 kg·ha￣(-1) . the average values were 924.15+ 19573. 117 27+25 52. 15 08- 395 and 50.14+ 13.29 kg·ha￣(-1). accounting for 3.00+ 113. 5 34 + 1.57. 1 71+0.57 and 0. 26 +0.22%of the total soiI C. N. P and K. The status of soil microbial pool nutrient in monsoon evergreen broadleaf forest was better compared with other vegetation types.