Abstract
Year of Publication 2012
Successful regeneration of bamboos from
seed is a key issue in the ecology of many tropical regions and the livelihoods
of their inhabitants. The gregarious monocarpy of many bamboos may be driven by
a need to satiate seed predators by seeding in abundance at infrequent
intervals. In long-lived clonal monocarps, seed production is expected to be
positively related to the success of the clone in generating more and larger
ramets during its lifetime. Ramification may be constrained by harvesting of
culms, but it is unclear whether the reduction in productivity is proportional
to the loss of reproductive biomass. We counted the seed produced by 661 culms
(ramet stems) sampled from 90 clumps of the gregariously monocarpic bamboo Schizostachyum dullooa that is intensively harvested by villagers
in northeastern India. The smallest clumps had fewer culms and few or no culms
more than one year old. Seed production was indeed positively related to culm
size and the number of culms in a clump. First-year culms were markedly more
productive than older culms after controlling for culm diameter and clump size.
There was a negative effect of clump size on productivity per culm which may
occur because clumps that had been harvested heavily were able to exploit
resources retained in rhizomes from harvested culms. Nevertheless, small clumps
produced much less seed than larger clumps, generating a risk of unknown
magnitude that heavily harvested stands of monocarpic bamboos may be unable to
satiate seed predators during their single opportunity for reproduction.
Key words: Bambuseae; clonal plant; clumping bamboo;
gregarious semelparity; India; predator satiation; sustainable harvest.
Authors:
Arun Jyoti Nath, Donald C. Franklin, Michael
J. Lawes, Mukta Chandra Das, and Ashesh Kumar Das
Journal Name and Issue: Biotropica 44(5): 699–704. (IF:
2.29)
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