6 research outputs found
Global pattern of leaf litter nitrogen and phosphorus in woody plants
Forest ecosystems exert an important influence on global biogeochemical cycles.
A global dataset of nitrogen (N) and phosphorus (P) concentrations in leaf-
litter of woody plants was compiled from the literature. Among the 677 data
sets, 482 included P concentrations and the N:P ratio. At a global scale, the
mean leaf-litter N and P and N:P ratio were 10.9 mg g-1, 0.85 mg g-1 and 18.3,
respectively. Leaf-litter N and P were significantly correlated. When the data
was grouped by continents, the highest mean N was found in Africa (19.5 mg g-1),
and the lowest in North America (8.18 mg g-1). P was significantly smaller in
the Asian Islands (Japan and Malaysia, 0.44 mg g-1) than on the Asian mainland.
For the global dataset, leaf-litter N increased linearly with mean annual
temperature and annual precipitation and decreased with latitude. Although leaf-
litter P showed no significant relationship with temperature, it declined
linearly with precipitation and there was a convex quadratic relationship with
latitude. For the global dataset and also for different functional groups (e.g.
shrubs, evergreen broadleaf, deciduous broadleaf, and conifers) the leaf-litter
N:P ratio generally followed a positive linear relationship with temperature and
precipitation, and showed a concave quadratic response with latitude. The
differences in leaf-litter N:P ratio among functional groups and among
continents should be taken into account when modeling biogeochemical cycles in
different regions as well as on a global scale