INVESTIGADORES
BERTILLER monica Beatriz
artículos
Título:
Leaf strategies and soil N across a regional humidity gradient in Patagonia.
Autor/es:
BERTILLER, M.B; MAZZARINO, M.J.; CARRERA, A.L.; DIEHL, P; SATTI, P; GOBBI, M.J.; SAIN, C.L.
Revista:
OECOLOGIA
Editorial:
Springer
Referencias:
Año: 2006 vol. 148 p. 612 - 624
ISSN:
0029-8549
Resumen:
We analyzed leaf traits
related to carbon- fixation, nutrient conservation strategies, and
decomposability and their relationships with potential N-mineralization and
microbial N in soil in 19 species of 5 dominant life forms growing in 40 sites
across a regional humidity gradient in northern Patagonia. We hypothesized that
(1) the shifting of species and life forms across the humidity gradient is
related to a shifting in traits of green and senesced leaves with some
overlapping among life forms, and (2) leaf traits associated with litter
decomposition are related to the potential dynamics of soil-N across the
humidity gradient. LMA in green leaves and P-resorption effciency decreased
with humidity while concentrations of lignin and total phenolics in green and
senesced leaves and P concentration in senesced leaves increased with humidity.
Soil C and N concentrations were positively correlated to humidity. Increasing
soil N concentration was related to increasing rates of absolute (per unit soil
mass) potential net N-mineralization and microbial-N flush. Relative (per unit
N mass) potential net N-mineralization and microbial-N flush decreased with
soil N and were inversely correlated to lignin concentration and C/N ratio in
senesced leaves. We found overlapping in N concentration and C/N ratio in green
and senesced leaves, P concentration in green leaves, and N resorption among
species and life forms across the humidity gradient. We concluded that (1) leaf
traits related to carbon fixation and the decomposition pathway significantly
varied with humidity and were not overlapped between plant life forms from dry
and humid habitats, (2) the largest overlapping among species and plant life
forms across the gradient occurred in those leaf traits related to N conservation
in the plant, and (3) life forms from humid habitats produce more recalcitrant
litter that induce lower rates of relative potential net N mineralization (per
unit N) than those of dry habitats.