In cool temperatures, trees keep these sugars in the leaf, but when it's warmer, the sugars shift to other parts of the plant.
Templer and her colleagues found that in higher temperatures trees weren't able to filter as much carbon dioxide and nitrogen as they would otherwise.
Fig. 3 Effects of longitude (a), latitude (b), annual precipitation (c), mean annual temperature (d), tree species richness (e), and tree size heterogeneity (f) on stand productivity of US inventory plots.
Fig. 1 Effects of longitude (a), latitude (b), annual precipitation (c), mean annual temperature (d), tree species richness (e), and tree size heterogeneity (f) on stand productivity of German inventory plots.
Fig. 7 Effects of longitude (a), latitude (b), annual precipitation (c), mean annual temperature (d), tree species richness (e), and stand density (f) on tree size heterogeneity of US inventory plots.
Fig. 5 Effects of longitude (a), latitude (b), annual precipitation (c), mean annual temperature (d), tree species richness (e), and stand density (f) on tree size heterogeneity of German inventory plots.
This field of study uses sophisticated statistical methods to derive meaning from scattered and variegated indirect indicators of past temperature — with tree rings being the most familiar example.
The 78-author paper, published Sunday in Nature Geoscience, used a variety of indirect indicators of temperature, from tree rings to pollen grains, to build on other work charting temperature shifts since the end of the last ice age — including the recent Marcott et al paper, explored here, which used seabed sediments to chart 11,000 years of temperatures.
The positive relationship often found between air temperature and tree growth is thought to be principally driven by the lengthening of the growing season (Lieth 1973; Kerkhoff et al. 2005).
Our study, which reaffirms the importance of salmon to riparian productivity and contributes new insight for the complex, spatiotemporal influences of salmon abundance, temperature and tree location relative to salmon upon conifer growth and δN levels.
