Temporal and spatial variation in soil resources in a deciduous woodland
Temporal and spatial variation in soil resources in a deciduous woodland
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DOI：
10.1046/j.1365-2745.1999.00390.x
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发表时间：
1999-08-01
影响因子：
5.5
通讯作者：
Fitter, AH
中科院分区：
文献类型：
--
作者：
Farley, RA;Fitter, AH
植物可以通过根系的增殖或离子吸收率的增加对营养丰富的斑块作出反应；因此，这些斑块被认为是植物生长的重要营养来源。然而，在多年生草本植物根系发育的尺度上，养分浓度的时空异质性尚不清楚对英国北约克郡的一个林地遗址进行了研究，以测量养分异质性的规模和程度。在2年的时间里，采用破坏性土壤取心法测量了磷酸盐、硝酸盐、铵、pH和土壤水分，并在较小的范围内使用根土壤溶液取样器测量了磷酸盐、硝酸盐和铵。土壤水分相对恒定，为0.6 g g（-1）新鲜土壤重量。所有其他变量均存在时间变化，但养分浓度峰值的时间无法预测在2 m以上的尺度上，土壤取心显示出磷酸盐、铵态氮和硝酸盐浓度的差异，这可能太大了，对多年生草本植物个体影响不大，但对树木可能很重要。然而，土壤溶液取样显示，在20厘米尺度上，硝酸盐和铵的差异为2至5倍；许多草本植物的根系会伸展到这样的距离局部地区出现的养分浓度峰值持续时间不超过4周。因此，如果植物要利用这些营养丰富的斑块，它们的根必须迅速作出反应研究表明，在某些自然生境中，局部营养丰富的地区可能成为植物的重要营养来源，特别是在营养可用性总体水平较低的情况下。因此，在根系觅食和种群研究中应考虑土壤的斑块性。
1 Plants can respond to nutrient-rich patches by proliferation of roots or by increased rates of ion uptake; such patches are therefore considered to be an important source of nutrients for plant growth. However, little is known about the spatial and temporal heterogeneity of nutrient concentration at scales that are applicable to the development of root systems of herbaceous perennial plants.2 A woodland site in North Yorkshire (UK) was studied to measure the scale and extent of nutrient heterogeneity. Phosphate, nitrate, ammonium, pH and soil moisture were measured by destructive soil coring over a period of 2 years, and phosphate, nitrate and ammonium were also measured at a smaller scale using Rhizon Soil Solution Samplers.3 Soil moisture was relatively constant at 0.6 g g(-1) fresh soil weight. Temporal variation was found in all other variables, but the timing of peaks in nutrient concentration was not predictable.4 Soil coring showed differences in phosphate, ammonium and nitrate concentrations at a scale of over 2 m, which may be too large a scale to affect individual herbaceous perennial plants but might be important for trees. However, the soil solution sampling showed two- to fivefold differences in nitrate and ammonium at scales of 20 cm; the root systems of many herbaceous plants will spread over such distances.5 Peaks in nutrient concentration that occurred in localized areas lasted no more than 4 weeks. Therefore if these nutrient-rich patches are to be utilized by plants, their roots must respond rapidly.6 The study showed that localized nutrient-rich areas may form an important source of nutrients for plants in some natural habitats, especially when the general levels of nutrient availability are low. Hence the patchy nature of the soil should be considered in root foraging and population studies.