Architecture, seasonal growth and interference in three grass species with different flowering phenologies in a tropical savanna
✍ Scribed by Raventos, Jose ;Silva, Juan F.
- Book ID
- 104621088
- Publisher
- Springer-Verlag
- Year
- 1988
- Tongue
- English
- Weight
- 626 KB
- Volume
- 75
- Category
- Article
- ISSN
- 1573-5052
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✦ Synopsis
In a field experiment we studied the relationships between architecture, seasonal aerial biomass growth and interference from neighbours in three savanna grass species differing in time of flowering: a precocious species (Elyonurus adustus), an early species (Leptocoryphium lanatum) and a late species (Andropogon semiberbis).
To detect the neighbour interference upon architecture and seasonal regrowth, we measured the leaf interception of a plane at different heights, when the species grew alone, in pairs and in groups of three. Although the three species differed widely in the spatial and temporal patterns of occupation of above-ground space, important levels of interference among neighbouring plants were detected. The species differ in: a) the pattern of space occupation when growing alone; b) the magnitude of the interference effect by the companion species; c) the change in pattern as a consequence of interference; d) their reaction to fire.
The interference is not symmetric and it is not related to phenological similarities based on flowering season.
L. lanatum was both the most impaired and the least impairing of the three species and the opposite is valid for A. semiberbis. The basal species (E. adustus and L. lanatum) showed a higher potential to produce leaf surface during the growth season than the tall species (A. semiberbis), but the stronger interference from the latter tended to equate their growth when the species grew in mixtures. In all three species interference led to a reduction of the growing period. Based on the analysis of growth at the various heights and the architectural peculiarities of the species we concluded that neighbour ~nterference is probably reducing both tillering and leafing in the basal species but only culm elongation and leafing in the erect species.
The species also differed in their reaction to fire. A. semiberbis and E. adustus showed a pulse of regrowth after the passing of fire which is missing in L. lanatum. In all cases the neighbour interference affected both the intensity of growth and the length of the growing period, but it did not affect either the height of the plants nor the reproductive phenology of these three grass species.