Conservation recommendations for Nee Soon 
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Floristic exploration of the Nee Soon catchment should continue, with more 
emphasis on epiphytes and lianas as these were under-represented in our surveys. In 
addition, a catchment-wide survey focused on identifying very large trees, e.g. >30-cm 
DBH, may yield more rediscoveries, new records, or rare species that can be targeted 
for conservation action. 
Faunal ecology 
Aquatic communities vary spatially across the Nee Soon freshwater swamp forest. 
The variations are responses to the hydrological conditions, principally stream 
depth characteristics. Depth is correlated with stream order (the order of branching), 
from source to confluence. A higher diversity of benthic macroinvertebrate, pelagic 
decapods and fish were observed in larger streams. However, this diversity was not 
necessarily representative of the least disturbed fauna for the swamp forest streams, 
because non-native invasive species were commoner (and added to the species total) 
in the larger streams. 
Spatial and temporal studies of the fish and decapods in the Nee Soon 
freshwater swamp forest indicate that there exists a healthy community of native fish 
and decapods within the Nee Soon freshwater swamp forest. However, the situation is 
different towards the lower catchment and the edge of the forest, where the community 
contains a large percentage of introduced species. Additionally, the main drivers of 
diversity and richness among the fish and decapod community appear to be substrate 
type, stream depth and stream order. 
With this in mind, an important recommendation is to maintain constant 
monitoring of the faunal communities in the Nee Soon freshwater swamp forest, 
especially in the more upstream sites, so as to ensure that introduced species do not 
successfully establish within such sites. If any individuals from an introduced species 
are found they should be immediately removed, as they may have adverse effects on 
native species once established, as has occured in many other places (Ogutu-Ohwayo, 
1990; Beisner et al., 2003). 
Additionally, the temporal results suggest that the Northeast monsoon period 
(December to February) is an important breeding period for several species of fish. 
Therefore, it is important that any form of disturbance in the streams during this period 
be minimised. Otherwise, there may be serious effects on the long-term survival and 
viability of these fish populations, something which cannot be afforded as many of the 
fish in the Nee Soon freshwater swamp forest are endangered in Singapore. 
Again, the lack of introduced species in the middle and upper catchment is 
heartening, and it is imperative that monitoring continues to be carried out to maintain 
this state of affairs and prevent establishment of introduced species deeper in the Nee 
Soon freshwater swamp forest. 
Invertebrate communities found at the downstream “edge habitat” sites closer 
to the Upper Seletar Reservoir spillway were more diverse (higher richness and 
abundance) than in the rest of the Nee Soon freshwater swamp forest. Nevertheless 
the aquatic community at the “edge habitat” sites was not indicative of a “healthy” 
forest stream system (Blakely et al., 2014). Macroinvertebrates such as chironomids 
