阿拉善荒漠草地几种灌木对土壤有效态养分的影响

Influence of Several Shrubs on Soil Available Nutrient in Alxa Desert Steppe

对阿拉善荒漠草地广泛分布的几种灌木、半灌木土壤有效态常量和微量营养元素的"肥岛"效应进行了研究。结果表明:①霸王、白刺、红砂和沙冬青提高了灌丛根部土壤速效Na、K、Fe和Mn的含量,而降低了灌从根部土壤速效Ca、Mg的含量;驼绒藜除对土壤速效Mg含量有显著影响外,对其他元素无显著的影响。②霸王、白刺和沙冬青对速效Na、K、Fe和Mn有明显的富集作用,对速效Ca负富集作用;红砂对速效Na有极强的富集作用,EA、EB分别为37.59和52.93;除红砂和驼绒藜对速效Mg有富集作用外,其余灌丛对速效Mg无富集作用。③灌丛周围土壤pH值与速效K、Fe和Zn含量呈显著负相关,与Ca呈正相关,与速效Na无相关性。霸王、白刺、沙冬青周围土壤速效Mg含量与pH值也呈显著正相关;除了霸王外,其他灌木周围土壤速效Mn含量都与pH值呈负相关。

‘Fertile islands＇ are formed under several shrubs and subshrubs which widely distribute in Alxa Desert Steppe, their soil available content of major elements and trace elements were studied in this paper. The results showed： ① Z. xanthoxylum, N. sibirica, R. soongorica and A. mongolicus increased soil available content of Na, K, Fe and Mn at the clump center, and decreased soil available content of Ca and Mg; C. lateens only increased soil available content of Mg, and there was no significant influence on other available nutrients. ② Z. xanthoxylum, N. sibirica, A. mongolicus had significant function on enrichment ratios for available Na, K, Fe and Mn, and had negative function on enrichment ratio for available Ca; R. soongorica had high function on enrichment ratios for available Na. Except for R. soonyorica, C. lateens, the other shrubs had no function on enrichment for available Mg. ③pH value has significantly nega- tive correlation with K, Fe and Zn content, but has significantly positive correlation with Ca content and Mg content, and no correlation with Na content; except for Z. xanthoxylum, the other shrubs existed negative correlation between pH value and Mn content.