Abstract
Background: Fine roots comprise a dynamic carbon pool in forests. Legumes, widespread in the tropics, have a specialized strategy of nitrogen acquisition. However, the belowground dynamics of this group are poorly understood. Scope: We studied the seasonal and spatial variation in surface fine root mass (FRM) and nodulation over 2 years in plantations of four legume species (Dalbergia retusa, Enterolobium cyclocarpum, Gliricidia sepium, Leptolobium panamense) in a dry forest in Costa Rica. We measured soil moisture, FRM, and nodule mass at 2 soil depths (0–15 and 15–30 cm) and at 2 distances from the tree bole (1 and 2 m). Mean FRM per species ranged from 10 to 17 g m−2 during the dry season to 86–116 g m−2 the following wet season. Species differed in belowground foraging strategies: G. sepium and L. panamense had ~41 % more roots in the surface layer, but in D. retusa plantations, 44.3 % more roots were in the deeper layer. In G. sepium and L. panamense, nodulation fluctuated seasonally, while the other species did not nodulate. Conclusions: FRM varied in synchrony with rainfall and responded to interannual precipitation anomalies. Thus, FRM is a sensitive component of the forest carbon pool, vulnerable to shifts in species composition and climate regimes.
Original language | English (US) |
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Pages (from-to) | 187-196 |
Number of pages | 10 |
Journal | Plant and Soil |
Volume | 388 |
Issue number | 1-2 |
DOIs | |
State | Published - Mar 2015 |
Bibliographical note
Publisher Copyright:© 2014, Springer International Publishing Switzerland.
Keywords
- Fine roots
- Legumes
- Nodulation
- Seasonality
- Tropical dry forests