| dc.contributor |
Ministerio de Educación y Ciencia (España) |
|
| dc.contributor |
Fundação para a Ciência e a Tecnologia (Portugal) |
|
| dc.creator |
García, Luis V. |
|
| dc.creator |
Maltez-Mouro, Sara |
|
| dc.creator |
Pérez-Ramos, Ignacio Manuel |
|
| dc.creator |
Freitas, Helena |
|
| dc.creator |
Marañón, Teodoro |
|
| dc.date |
2008-05-19T08:17:02Z |
|
| dc.date |
2008-05-19T08:17:02Z |
|
| dc.date |
2006 |
|
| dc.date.accessioned |
2017-01-31T01:21:41Z |
|
| dc.date.available |
2017-01-31T01:21:41Z |
|
| dc.identifier |
1399-1183 |
|
| dc.identifier |
http://hdl.handle.net/10261/4327 |
|
| dc.identifier.uri |
http://dspace.mediu.edu.my:8181/xmlui/handle/10261/4327 |
|
| dc.description |
The forest canopy modifies the availability of resources (light, water, and soil nutrients)
in the understorey. In this paper we analyze the relationships between woody canopy
density, litter accumulation, and topsoil N and P availability in the understorey of two
oak forests: one in southern Portugal and the other in southern Spain. Both forests
persist on low-nutrient soils, particularly poor in P. We hypothesize that direct and
indirect effects of the canopy overstorey cause opposite gradients in the availability of
essential resources (light and key soil nutrients) in the understorey. In both studied
forests we found significant relationships between the overall canopy density, light availability,
topsoil litter accumulation, and the availability of N and P, which frequently
limit plant growth. Path analysis (by Shipley’s d-sep method) showed that the available
data were consistent with the proposed causal model. The average values of soil variables
at the end quartiles of the light-availability gradient were compared. Results showed
large differences in litter accumulation (~30×) and available-N and -P topsoil concentrations
(~3×) in the Spanish forest (with the wider environmental gradient). Furthermore,
P increased from the ‘very low’ range to the ‘low’ or even the ‘optimum’ range of
availability (according to standard plant growth criteria), which suggests potential effects
on the growth of the understorey plant species. We conclude that the counteracting
gradients of the essential resources -light and nutrients- in the forest understorey
resulted from direct and indirect effects of the canopy overstorey, respectively. We suggest
that these counteracting effects of the woody canopy on essential resources of different
nature must be considered when interpreting the patterns of understorey plant populations
and communities. |
|
| dc.description |
The spanish MEC (CGL2005-05830-C03-01-BOS, DINAMED project) and the Portuguese FCT(SFRH/BD/8322/2002 grant to SMM)supported the research. |
|
| dc.description |
Peer reviewed |
|
| dc.format |
942473 bytes |
|
| dc.format |
application/pdf |
|
| dc.language |
eng |
|
| dc.relation |
Web Ecology 6: 67-74 (2008). |
|
| dc.rights |
openAccess |
|
| dc.title |
Counteracting gradients of light and soil nutrients in the understorey of Mediterranean oak forests. |
|
| dc.type |
Artículo |
|