caa a22 4500 477109454 CHVBK 20180405111604.0 cr unu---uuuuu 170330e19960601xx s 000 0 eng 10.1007/BF00010459 doi (NATIONALLICENCE)springer-10.1007/BF00010459 Temporal dynamics of soil spatial heterogeneity in sagebrush-wheatgrass steppe during a growing season [Elektronische Daten] [R. Ryel, M. Caldwell, J. Manwaring] Variability in five soil resources essential for plant growth (NH4 +, NO3 -, P, K and soil moisture) was quantified using univariate, multivariate and geostatistical techniques in a sagebrush-grass steppe ecosystem at three times (early April, June and August) during the 1994 growing season. Samples were collected every meter in a 10 × 10-m ‘macrogrid', every 20 cm within nested 1 × 1-m ‘minigrids', and every 3 cm within additionally nested 15 × 15-cm ‘microgrids'. Strong autocorrelation for all variables in the three sample periods was only found over distances less than 2 m, indicating that patches of high internal uniformity in this soil were smaller than 2 m during the growing season. Differences in semivariograms between sample periods were most pronounced for NO3 -, NH4 + and soil moisture, variables that we consider to primarily limit plant growth in this system. The distance over which sample points were autocorrelated for NO3 -, NH4 + and soil moisture increased from April to June. In contrast P and K, which are relatively more abundant at the study site, exhibited relatively constant semivariance patterns over the three sample periods. Weak correlation was found between samples collected in the three sample periods for N and soil moisture indicating that the spatial pattern of these limiting resources changed between sample periods. However, P and K had highly significant correlations (p<0.00001) among sample periods, indicating that the distributional patterns of these relatively more abundant resources remained rather constant. There were strong negative correlations between P and K and distance from the base of shrubs for all sample times (p<0.001), indicating an increase in P and K close to shrubs. Similar strong negative correlations were not found between distance from the shrubs and levels of NH4 +, NO3 -, or soil moisture, nor for any soil variable and distance from perennial tussock grasses. Changes in patterns of nutrient and soil moisture variability within a growing season suggest that not only must plants acquire soil resources that vary in time and space, but that they may also have to adjust to different scales of resource patchiness during the season. Kluwer Academic Publishers, 1996 Agropyron desertorum nationallicence Artemisia tridentata nationallicence nutrient availability nationallicence resource patchiness nationallicence sagebrush-grass steppe nationallicence temporal variability nationallicence Ryel R. Department of Rangeland Resources, Utah State University, 84322-5230, Logan, UT, USA aut Caldwell M. Department of Rangeland Resources, Utah State University, 84322-5230, Logan, UT, USA aut Manwaring J. Department of Rangeland Resources, Utah State University, 84322-5230, Logan, UT, USA aut Plant and Soil Kluwer Academic Publishers; gopher://gopher:wkap.nl 184/2(1996-06-01), 299-309 0032-079X 184:2<299 1996 184 11104 https://doi.org/10.1007/BF00010459 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00010459 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ryel R. Department of Rangeland Resources, Utah State University, 84322-5230, Logan, UT, USA aut NATIONALLICENCE 700 1- Caldwell M. Department of Rangeland Resources, Utah State University, 84322-5230, Logan, UT, USA aut NATIONALLICENCE 700 1- Manwaring J. Department of Rangeland Resources, Utah State University, 84322-5230, Logan, UT, USA aut NATIONALLICENCE 773 0- Plant and Soil Kluwer Academic Publishers; gopher://gopher:wkap.nl/ 184/2(1996-06-01), 299-309 0032-079X 184:2<299 1996 184 11104 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer