Abstract

Both aboveground and belowground climate affects net primary production (NNP) and forest growth. Little is known about how above and belowground factors interact. The BIOMASS-model was tested to simulate photosynthetic recovery over a wide range of soil temperatures created by snow cover manipulations on tree-scale plots in a 20-year-old Scots pine stand in northern Sweden. The differences in timing of soil warming between the plots covered a span of two months. Carbon assimilation in needles, sap flow, needle water potential and climatic parameters were measured in the field. The simulations revealed that an early start of soil warming gave a relatively early photosynthetic recovery and a 7.5% increase of NPP. Late soil warming delayed the photosynthetic recovery and reduced the NPP by 13.7%. This indicated that soil temperature needed to be accounted for, as well as air temperature, when analysing photosynthetic recovery and NPP in boreal environment. The effects of differences in soil temperature were reflected in the simulated photosynthetic recovery. The model did not fully capture the delay of photosynthetic recovery caused by a late soil warming. It was possible to integrate the complexity of the soil climate effects into a threshold date for soil thaw, using sapflow measurements together with information about air temperature and a day degree sum, as long as water availability was not limiting water uptake by roots. Although a more realistic mechanism than that currently in BIOMASS is desirable as climate change shifts the typical patterns of interplay between air and soil temperature dynamics.

Keywords

low temperature; net primary production; carbon assimilation; sap flow; water potential; BIOMASS; pinus sylvestris

Published in

European Journal of Forest Research
2008, Volume: 127, number: 1, pages: 71-79

SLU Authors

• Bergh, Johan

  • Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
    

• Lundmark, Tomas

  • Unit for Field-based Forest Research, Swedish University of Agricultural Sciences
    

• Bishop, Kevin

  • Department of Environmental Assessment, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG13 Take urgent action to combat climate change and its impacts


UKÄ Subject classification

Forest Science
Fish and Aquacultural Science


Publication identifier

DOI: https://doi.org/10.1007/s10342-007-0184-4

Permanent link to this page (URI)

https://res.slu.se/id/publ/17408