Recovery of photosynthetic capacity in Scots pine: a model analysis of forest plots with contrasting soil temperature |
| |
| Authors: | Per-Erik Mellander Johan Bergh Tomas Lundmark Kevin Bishop |
| |
| Institution: | (1) Department of Natural and Environmental Sciences, Mid Sweden University, 851 70 Sundsvall, Sweden;(2) Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, P.O. Box 49, 23053 Alnarp, Sweden;(3) Vindeln Experimental Forests, Swedish University of Agricultural Sciences, 922 91 Vindeln, Sweden;(4) Department of Environmental Assessment, Swedish University of Agricultural Sciences, P.O. Box 7050, 750 07 Uppsala, Sweden |
| |
| 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 |
| 本文献已被 SpringerLink 等数据库收录！ |
|
