图3. 植物养分捕获策略(NASs)随成土年龄的变化。AM, 丛枝菌根; CR, 排根; DR, 胡萝卜状根; ECM, 外生菌根; FR, 细根; N fixation, 固氮; OM, 兰花菌根; Ptase, 磷酸酶; SR, 固沙根; VR, 毛状根。背景色的深浅代表植物NASs多样性的高低。图示顶部不规则图形的宽度大小表示3种NASs随土壤年龄的变化趋势。图中圆圈大小代表不同时期NASs对植物捕获养分的相对重要性, 虚线圈代表细根策略的相对重要性还缺少足够的证据。土壤氮(N)和磷(P)库颜色的深浅代表土壤总N和P库的大小。

Fig. 3. Temporal changes in plant nutrient-acquisition strategies (NASs) with increasing soil age. AM, arbuscular mycorrhiza; CR, cluster roots; DR, dauciform roots; ECM, ectomycorrhiza; FR, fine roots; N fixation, nitrogen fixation; OM, orchid mycorrhiza; Ptase, phosphatases; SR, sand-banding roots; VR, vellozioid roots. The change in intensity of the background color represents abundance in diversity of NASs. The width of irregular polygons on the top of the figure represents the general trend of three classes of NASs with soil age. The size of cycles represents the relative importance of a particular NAS in plant acquiring nutrients in different stages of pedogenesis. The dotted circle of FR indicates that more evidence is needed to support the role of the fine root strategy in plant acquiring nutrients. The change in intensity of color in soil nitrogen (N) and phosphorus (P) pool rectangles represents variation in total N and P availability, respectively, with soil age.