Biogeochemical recuperation is consistent during succession across secondary lowland tropical forest

Authors: SULLIVAN, BEN - University Of Nevada; Nifong, Rachel; NASTO, MEGAN - University Of Montana; ALVAREZ-CLARE, SILVIA - University Of Montana; DENCKER, CAMIE - University Of Nevada; SOPER, FIONA - University Of Montana; SHOEMAKER, KEVIN - University Of Nevada; ISHIDA, YOKO - James Cook University; ZARAGOZA-CASTELLS, JOANA - University Of Exeter; DAVIDSON, ERIC - University Of Maryland; CLEVELAND, CORY - University Of Montana

Submitted to: Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/7/2019
Publication Date: 2/6/2019
Citation: Sullivan, B.W., Nifong, R.L., Nasto, M.K., Alvarez-Clare, S., Dencker, C., Soper, F.M., Shoemaker, K.T., Ishida, Y.F., Zaragoza-Castells, J., Davidson, E.A., Cleveland, C. 2019. Biogeochemical recuperation is consistent during succession across secondary lowland tropical forest. Ecology. https://doi.org/10.1002/ecy.2641.
DOI: https://doi.org/10.1002/ecy.2641

Interpretive Summary: Land use change has greatly increased the amount of secondary forest relative to mature forest in the lowland tropical rainforests worldwide. In order for secondary forest to grow back after clearing, soil nutrient supplies must be sufficient after disturbance and individual studies have found that soil nutrient availability can rapidly recover to enable secondary forest succession. Here, we examined soil and plant nutrient dynamics during secondary succession and show that shifts in soil and plant nutrient availability during secondary forest succession are consistent across the tropics. Additionally, N and P stocks in secondary forest recover to levels similar to mature forest. Our results imply that predictable nutrient recuperation occurs across a diverse and productive ecosystem which can support future forest growth in tropical lowland forests.

Technical Abstract: High rates of land conversion and land use change have vastly increased the proportion of secondary forest in the lowland tropics relative to mature forest. Nutrients like nitrogen (N) and phosphorus (P) must be present in sufficient quantities to sustain high rates of net primary production and to replenish the nutrients lost during land use prior to secondary forest establishment. Biogeochemical theory and conceptual models based on individual studies suggest that N can recuperate during secondary forest recovery, especially relative to P. Here, we synthesized 23 metrics of N and P in soil and plants from 45 secondary forest chronosequences located in wet tropical forest to empirically explore: 1) whether nutrient recuperation is a common phenomenon; 2) what metrics of N and P in soil and plants recuperate most consistently; 3) if the recuperation of nutrients during succession leads to similar nutrient concentrations and fluxes as those in mature forest; and 4) if nutrients are significantly related to site characteristics including disturbance history, climate, and soils. During secondary forest succession, nine metrics of N and/or P cycling changed consistently and substantially during succession. We found strong evidence that N concentrations and fluxes in both plants and soil increase during secondary succession, but we also show that soil total P concentrations increased in surface soil. The change in nutrients during secondary succession was similar whether mature forest was included or excluded from analysis, indicating that nutrient recuperation in secondary forest leads to biogeochemical conditions that are similar to those of mature forest. Further, of the N and P metrics that recuperated, only soil total P and foliar d15N were strongly influenced by site characteristics like climate, soils, or disturbance history. Predictable nutrient recuperation across a diverse and productive ecosystem may support future forest growth and could provide a means to quantify successful restoration of ecosystem function in secondary tropical forest beyond biomass or species composition.