Total Carbon Stock and Potential Carbon Sequestration Economic Value of Mukogodo Forest-Landscape Ecosystem in Drylands of Northern Kenya

Carbon sequestration is one of the important ecosystem services provided by forested landscapes. Dry forests have high potential for carbon storage. However, their potential to store and sequester carbon is poorly understood in Kenya. Moreover, past attempts to estimate carbon stock have ignored drylands ecosystem heterogeneity. This study assessed the potential of Mukogodo dryland forest-landscape in offsetting carbon dioxide through carbon sequestration and storage. Four carbon pools (above and below ground biomass, soil, dead wood and litter) were analyzed. A total of 51 (400 m2) sample plots were established using stratified-random sampling technique to estimate biomass across six vegetation classes in three landscape types (forest reserve, ranches and conservancies) using nested-plot design. Above ground biomass was determined using generalized multispecies model with diameter at breast height, height and wood density as variables. Below ground, soil, litter and dead wood biomass;carbon stocks and carbon dioxide equivalents (CO2eq) were estimated using secondary information. The CO2eq was multiplied by current prices of carbon trade to compute carbon sequestration value. Mean ± SE of biomass and carbon was determined across vegetation and landscape types and mean differences tested by one-way Analysis of Variance. Mean biomass and carbon was about 79.15 ± 40.22 TB ha-1 and 37.25 ± 18.89 TC ha-1 respectively. Cumulative carbon stock was estimated at 682.08 TC ha-1;forest reserve (251.57 TC ha-1) had significantly high levels of carbon stocks compared to ranches (209.78 TC ha-1) and conservancies (220.73 TC ha-1, P = 0.000). Further, closed forest significantly contributed to the overall biomass and carbon stock (58%). The carbon sequestration potential was about 19.9MTCO2eq with most conservative worth of KES 39.9B (US$40M) per annum. The high carbon stock in the landscape shows the potential of dryland ecosystems as carbon sink for climate change mitigation. However, for communities to benefit from bio-carbon funds in future, sustainable landscape management and restorative measures should be practiced to enhance carbon storage and provision of other ecosystem services.

Recovery Status and Livestock Use of a Kenyan Montane Forest a Decade after Cessation of Human Encroachment

Montane forest ecosystems support biodiversity and provide varied ecosystem services to adjacent and downstream human communities. However, human-induced disturbances are common in many of these ecosystems, threatening their capacity to sustain their functions. This study assessed the status of woody vegetation and livestock use of a Kenyan montane forest 10 years after government-sanctioned cessation of human encroachment. The findings can inform suitable interventions that support recovery of abandoned forest settlements subjected to continuous anthropogenic disturbances. Selected woody vegetation attributes and livestock disturbance indicators were assessed across three human-driven disturbance regimes (light, moderate and heavy) using stratified-systematic sampling technique. Data on the extent of community dependence on forest grazing were collected from 381 randomly selected forest adjacent households using semi-structured questionnaires. Information on the palatability of plants to livestock was obtained from Focus Group Discussions. Vegetation data were analyzed using linear mixed models, while descriptive analysis was applied on household survey data. A total of 33 woody plant species belonging to 22 families were identified, out of which 55% were perceived to be unpalatable to livestock. Species richness, species diversity, stem density and basal areas declined significantly with increasing levels of disturbance. Specifically, these attributes were 59% - 98% lower in heavily disturbed sites than in moderately and lightly disturbed sites. A vast majority (88%) of the sampled households grazed their livestock in the forest throughout the year. Evidence from this study indicates that intense past and ongoing anthropogenic disturbances caused significant negative effects on the forest vegetation condition, and lowered its capacity to recover. Forest managers should prioritize minimizing recurrent anthropogenic disturbances as the forest recovers to ensure successful succession and sustainable provision of ecosystem services.