TY - JOUR

T1 - Vegetation strategies for nitrogen and potassium acquisition along a climate and vegetation gradient

T2 - From semi-desert to temperate rainforest

AU - Stock, Svenja C.

AU - Koester, Moritz

AU - Nájera, Francisco

AU - Boy, Jens

AU - Matus, Francisco

AU - Merino, Carolina

AU - Abdallah, Khaled

AU - Spielvogel, Sandra

AU - Gorbushina, Anna A.

AU - Dippold, Michaela A.

AU - Kuzyakov, Yakov

N1 - Funding Information: We thank the Chilean National Park Service Corporación Nacional Forestal (CONAF) for the permission to work in the National Park La Campana and the National Park Nahuelbuta as well as the Center for Advanced Research in Arid Zones (CEAZA) for the possibility to work in the National Reserve Santa Gracia. We also thank Karin Schmidt for her support with lab analyses as well as the whole team of the Centre for Stable Isotope Research and Analysis (KOSI) at the University of Göttingen. We also wish to thank two anonymous reviewers for their constructive and thoughtful feedback on this manuscript. This study was funded by the German Research Foundation (DFG) [project number KU 1184/36-1 and DI 2136-11] within the Priority Program 1803 ‘EarthShape – Earth Surface Shaping by Biota’. Yakov Kuzyakov thanks the Program of Competitive Growth of Kazan Federal University "Priority 2030", and the RUDN University Strategic Academic Leadership Program.

PY - 2022/11/1

Y1 - 2022/11/1

N2 - Nutrient acquisition strategies of plants regulate water flow and mass transport within ecosystems, shaping earth surface processes. Understanding plant strategies under current conditions is important to assess and predict responses of natural ecosystems to future climate and environmental changes. Nitrogen (N) and potassium (K) (re-)utilization from topsoil and their acquisition from subsoil and saprolite were evaluated in a continental transect, encompassing three study sites – an arid shrubland, a mediterranean woodland, and a temperate rainforest – on similar granitoid parent material in the Chilean Coastal Cordillera. The short-term (<1 year) plant N and K acquisition was traced with 15N and the K analogs rubidium and cesium. To do so, the tracers were either injected into topsoil, subsoil, or saprolite, in the immediate vicinity of eight individual plants per study site and injection depth. The long-term (>decades) K uplift by plants was investigated by the vertical distribution of exchangeable K+ and Na+. Recoveries of 15N and K analogs by arid shrubland plants were similar from topsoil, subsoil, and saprolite. Mediterranean woodland shrubs recovered the tracers primarily from topsoil (i.e., 89 % of recovered 15N and 84 % of recovered K analogs). Forest plants recovered the tracers from topsoil (15N = 49 %, K analogs = 57 %) and partially from greater depth: 38 % of recovered 15N and 43 % of recovered K analogs were acquired from subsoil and saprolite, respectively. Low nutrient accessibility in the topsoil (e.g., because of frequent droughts) drives shrubland plants to expand their N and K uptake to deeper and moister soil and saprolite. Woodland and forest plants dominantly recycled nutrients from topsoil. In the forest, this strategy was complemented by short-term uplift of N and K from depth. The vertical distribution of exchangeable K indicated long-term uplift of K by roots in all three sites. This highlighted that long-term K uplift from depth complements the nutrient budget across the continental transect.

AB - Nutrient acquisition strategies of plants regulate water flow and mass transport within ecosystems, shaping earth surface processes. Understanding plant strategies under current conditions is important to assess and predict responses of natural ecosystems to future climate and environmental changes. Nitrogen (N) and potassium (K) (re-)utilization from topsoil and their acquisition from subsoil and saprolite were evaluated in a continental transect, encompassing three study sites – an arid shrubland, a mediterranean woodland, and a temperate rainforest – on similar granitoid parent material in the Chilean Coastal Cordillera. The short-term (<1 year) plant N and K acquisition was traced with 15N and the K analogs rubidium and cesium. To do so, the tracers were either injected into topsoil, subsoil, or saprolite, in the immediate vicinity of eight individual plants per study site and injection depth. The long-term (>decades) K uplift by plants was investigated by the vertical distribution of exchangeable K+ and Na+. Recoveries of 15N and K analogs by arid shrubland plants were similar from topsoil, subsoil, and saprolite. Mediterranean woodland shrubs recovered the tracers primarily from topsoil (i.e., 89 % of recovered 15N and 84 % of recovered K analogs). Forest plants recovered the tracers from topsoil (15N = 49 %, K analogs = 57 %) and partially from greater depth: 38 % of recovered 15N and 43 % of recovered K analogs were acquired from subsoil and saprolite, respectively. Low nutrient accessibility in the topsoil (e.g., because of frequent droughts) drives shrubland plants to expand their N and K uptake to deeper and moister soil and saprolite. Woodland and forest plants dominantly recycled nutrients from topsoil. In the forest, this strategy was complemented by short-term uplift of N and K from depth. The vertical distribution of exchangeable K indicated long-term uplift of K by roots in all three sites. This highlighted that long-term K uplift from depth complements the nutrient budget across the continental transect.

KW - (semi)arid to humid-temperate natural ecosystems

KW - N and K analog tracer

KW - Chilean Coastal Cordillera

KW - Nutrient cycles

KW - Nutrient uplift and recycling

KW - Subsoil nutrient tracing

UR - http://www.scopus.com/inward/record.url?scp=85135410369&partnerID=8YFLogxK

U2 - 10.1016/j.geoderma.2022.116077

DO - 10.1016/j.geoderma.2022.116077

M3 - Article

AN - SCOPUS:85135410369

VL - 425

JO - GEODERMA

JF - GEODERMA

SN - 0016-7061

M1 - 116077

ER -