Sustainable utilisation of Non Timber Forest Products (NTFPS) is a widely accepted forestry management approach. Unfortunately the sustainability of NTFPS in high demand like the wild climbers used by local communities is rarely investigated over a period of time. Yet extraction of these wild climbers by local community for food security purposes has been on going in Bwindi Impenetrable National Park(BINP) since 1994. This study is a precursor to a baseline study on the role of wild climbers around BINP for food security and ecological impacts of their harvest carried out by ITFC ( Bitariho and Akampurira, 2019). The study was carried out in Bwindi Impenetrable National Park in the parishes of Rutungunda, Eastern Ward and Southern Ward, where forest wild climbers harvesting by the local people was legalized since 1994. The same sampling design and sampling plots used by (Bitariho and Akampurira 2019) in 2018 were maintained for this study too. The individuals that were re-measured in this study were easily identified by the plastic tags tired around them in 2018. Our study focused on the same wild climbers that were studied a year before by (Bitariho and Akampurira 2019) and these included: Smilax anceps, Salacia elegans, Monanthotaxis littoralis, Toddalia assiatica, Loeseneriella apocynoides, Dracaena laxissima, Pristimera gracilifolia, Embelia liberiana, Enfulensia Montana and Rytigynia rwenzoriensis.
Results show that there was hardly any significant difference between the population structure of wild climbers in this study and those observed by Bitariho and Akampurira,(2019). The population structure for seven of the 10 harvested wild climbers (Dracaena laxissima, Smilax anceps, Pristimera gracilifolia, Embelia liberiana, Enfulensia Montana, Salacia elegans and Rytigynia rwenzoriensis) depicted healthy sustainable populations. As they exhibited an inverted ‘J’ and bell shaped type of diameter class distribution that is characteristic of plant populations that are cable of self-replicating. On the other hand population of Loeseneriella apocynoides and Monanthotaxis littoralis exhibited population structure of species that have experienced severe harvest impacts. Over 90% of the plants are re-sprouts and there are very few harvestable mature stems, indicating the plants have been overexploited. Loeseneriella apocynoides and Monanthotaxis littoralis are perhaps one of most demanded wild climbers usually used in making of tea harvesting baskets in the northern part of Bwindi. The growth of the tea economy in north of Bwindi over the past 20 years is primarily linked to the over exploitation of these species. The analysis of the basal areas of the wild climber their variation with environmental factors showed that only the Dracaena laxissima basal area was significantly (p<0.005) associated with environmental variables; Canopy, herb cover, tree cover and shrub cover. The variation of growth rate with tree diameters showed that Draceana laxissima (GLMM, x²= , DF = 1, P = 0.03324) and Smilax anceps (GLMM, x²= , DF = 1, P = 0.00423) demonstrated significant relationship with their growth rates.
In conclusion Monanthotaxis littoralis and Loesenerialla apocynoides demonstrated a population structure that has suffered the negative impacts of over harvesting or un sustainable harvesting . It is therefore important to restrict their harvest and continue their monitoring. But even perhaps more important is for the park management to work with local communities to identify potential alternatives that can help address the food security needs of local communities around Bwindi.