Koide R T, Huenneke L F, Mooney H A
Department of Biological Sciences, Stanford University, 94305, Stanford, CA, USA.
Oecologia. 1987 May;72(2):284-290. doi: 10.1007/BF00379280.
Portions of an annual serpentine grassland community in California are subject to frequent gopher mound formation. Consequently, studies were undertaken to characterize the effects of mound soils on plant growth and ion uptake. For two of the dominant annual species (Bromus mollis L. and Plantago erecta Morris), growth was reduced in gopher mound soil relative to that in inter-mound soil. A similar reduction in growth was found for plants grown in soils collected at a depth corresponding to the depth of gopher burrowing. This reduction in growth was associated with lower total P and N contents of the soil which were reflected in lower shoot contents of N and P. Additional experiments, however, showed that reduced N and P availabilities in mound soil were not entirely responsible for the growth reduction. Similarly, shoot Ca/Mg ratios were reduced in mound soil but additions of Ca improved the Ca/Mg ratio without improving growth. Growth reductions were associated with altered shoot concentrations of microelements, particularly elevated levels of Mn. A competition experiment between Plantago and Bromus showed that Bromus was more competitive than Plantago in mound and inter-mound soils and that soil type had only small affects on the nature of the interaction between the two species.
加利福尼亚州一年生蛇纹石草原群落的部分区域经常形成囊鼠土丘。因此，开展了相关研究来描述土丘土壤对植物生长和离子吸收的影响。对于两种优势一年生植物（软雀麦和直立车前），相对于丘间土壤，囊鼠土丘土壤中的植物生长受到抑制。在对应囊鼠洞穴深度采集的土壤中种植的植物，也出现了类似的生长抑制现象。这种生长抑制与土壤中较低的总磷和总氮含量有关，这反映在地上部分较低的氮和磷含量上。然而，额外的实验表明，土丘土壤中氮和磷有效性的降低并非生长抑制的全部原因。同样，土丘土壤中地上部分的钙/镁比值降低，但添加钙可改善钙/镁比值，却不能促进生长。生长抑制与地上部分微量元素浓度的改变有关，特别是锰含量升高。车前和雀麦之间的竞争实验表明，在土丘和丘间土壤中，雀麦比车前更具竞争力，且土壤类型对这两个物种之间相互作用的性质影响较小。
