A Ecological Baseline Surveys Of: - Lake Bisina - Nature Uganda

Layer Family Species % cover Life form
Polygonaceae Polygonum salicifolium 5 P
Polygonaceae Polygonum setolosum 1 P
Rhamnaceae Maesopsis eminii 1 P
Sapindaceae Allophylus Africana + P
Solanaceae Lycopersicon esculenta + A
Solanaceae Solanum nigrum 1 A
Solanaceae Solanum sessilistellatum 1 P
Solanaceae Solanum tuberosum 2 A
Solanaceae Withania somnifera + A
Tiliaceae Grewia bicolor 2 P
Tiliaceae Grewia similis 1 P
Tiliaceae Triumfetta macrophylla 1 P
Typhaceae Typha latifolia 1 P
Ulmaceae Chaetacme aristata + P
Vitaceae Cissus rotundifolia 1 P
Vitaceae Cyphostemma adenocaule 1 P
Bare bround 3
Note: P = Perennial and A = Annual
4.1.7.2 Ecosystems challenges
This ecosystem has been highly modified through:-clearing vegetation and reclaiming seasonally
flooded valleys for farming leading to biodiversity loss and soil erosion starting at the bare patches
slopes after clearing. This is expected to completely change the species dynamics. The anticipated
adverse impacts include: Species loss, soil fragility, introduction of invasive species, siltation of the
wetland and flash flooding.
4.1.7.3 Environment and vegetation management
Plant cover is effective in preventing erosion to the extent that it absorbs the kinetic energy of
raindrops, covers a large proportion of the soil during periods of the year when rainfall is heavy,
slows down runoff, and keeps the soil surface porous (Zhang et al., 2005). Whatever the slope,
extent of soil fragility or climatic conditions, complete plant cover ensures a high level of soil and
water conservation. Plant cover may have a priority in any effort to improve on water management,
infiltration, biomass production and soil conservation. Some researchers have used plant cover as
an indicator to assess ecosystem functional status in restoration projects (Maestre et al., 2006).
Plant cover can be used to compare the abundance (dominance) of species of widely different
growth forms, because it is not biased by the size and distribution of individuals. Only 3 % of the
land was found to be bare, without plant cover. However, this is a high percentage that exposes
the ecosystem to the effects of erosion if not monitored and maintained well. This being a fragile
ecosystem, much of it should not be exposed. It was observed that diversity of herbs was higher
than that of shrubs and trees. Fortunately, most of the dominating herbs are perennial species. For
monitoring purposes, if the annual herbs dominate over the perennial ones, chances of getting
larger bare patches will increase hence putting the ecosystem at an even greater risk of erosion.
Dominance of annual species is expected if more land is cleared for agriculture. This being a wetland,
the indicator species include all those recorded for family Cyperaceae as well as the following
associated species: Echinochloa pyramidalis, Enydra fluctuans; families Nymphaceae, Typhaceae
and Alismataceae (see Table 1). Significant changes in the estimated cover for the indicator species
will directly imply that the negative effects of human disturbance are acting on the ecosystem.
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Ecological Baseline Surveys of Lake Bisina, Lake Opeta, Lake Mburo and Nakivali Wetlands Systems