Biomass Energy Resource of the Highland Bamboo (<i>Yushania alpina</i>) and Its Potential for Sustainable Exploitation in Southern Aberdares Forest

Yushania alpina is the only bamboo species native to Kenya and covers about 150,000 ha growing in pure or mixed stands in the montane forests. The Aberdare forest is one of the natural habitats for Y. alpine occupying an area of 6419 ha mainly in the water catchment areas. The growing human population and depletion of other forest resources have necessitated the exploration of Y. alpine as a source of energy. This paper assessed the quantity of Y. alpine available for biomass energy and its potential for sustainable exploitation. Plots were laid on area maps to cater for altitude and distance from farms. The study area was stratified into three altitudinal zones: A (2220 - 2330 m), B (2331 - 2440 m) and C (2441 - 2550 m). The initial sampling plot of 10 m × 10 m was located randomly 500 m from the edge of the forest while the subsequent plots were laid out systematically at intervals of 500 m. In each plot, a total enumeration and biomass estimation of bamboo clumps were done using Muchiri and Muga (2013) [1] method. Bamboo samples and those of commonly used biomass energy sources were analysed for calorific value using bomb calorimeter. In addition, data for quantities of biomass energy used by some local industries were used to estimate the amount of bamboo required. The mean stocking was 19,981 (20,000) culms ha-1, and varied significantly among altitude strata and distance from adjacent farms. The mean biomass density and energy content were 86 tons/ha and 380,893 Kca/ha respectively with the higher altitudinal stratum (zone C) having the highest means (114 tons/ha) while the lower stratum (zone A) had the lowest (65 tons/ha). The energy needed by sampled local industries was 416,276,266 Kcal per year against 2.4 billion Kcal available in the bamboo forest. This implies that the bamboo forest in its present stocking can provide biomass energy for these local industries for more than five years. With bamboo maturing with less than five years, the forest can sustainably provide the required energy while still providing its environmental services.

Estimation of Above Ground Biomass in Forests Using Alos Palsar Data in Kericho and Aberdare Ranges

Above Ground Biomass is one of the six pools identified in the inventory of forest resources and estimation of greenhouse gas emissions and sinks from the forestry sector. The pool varies by management practices in different agro-ecological or agro-climatic zones in forests. The quantification of above ground biomass (AGB) hence carbon sequestration in forests has been very difficult due to the immense costs required. This research was done to estimate AGB using ALOS PALSAR L band data (HH, HV polarisation) acquired in 2009 in relation with ground measurements data in Kericho and Aberdares ranges in Kenya. Tree data information was obtained from ground measurement of DBH and tree heights in 100 circular plots of 15 m radius, by use of random sampling technique. ALOS PALSAR image is advantageous for its active microwave sensor using L-band frequency to achieve cloud free imageries, and the ability of long wavelength cross-polarization to estimate AGB accurately for tropical forests. The variations result between Natural and plantation forest for measured and estimated biomass in Kericho HV band regression value was 0.880 and HH band was 0.520. In Aberdare ranges HV regression value of 0.708 and HH band regression value of 0.511 for measured and estimated biomass respectively. The variations can be explained by the influence of different management regimes induced human disturbances, forest stand age, density, species composition, and trees diameter distribution. However, further research is required to investigate how strong these factors affect relationship between AGB and Alos Palsar backscatters.

Effects of Sawdust, Forest Soil and Cow Dung Mixtures on Growth Characteristics of Blue Gum (<i>Eucalyptus saligna</i>) Seedlings in South Kinangop Forest, Nyandarua, Kenya

Forestation programs, in Kenya have been hindered by, among others, high cost of tree seedling production and longtime seedlings stay in the nursery. This has been attributed to poor quality of forest soil and unavailability of alternative growth media. Study was carried out in South Kinangop forest station to evaluate the potential of mixing sawdust and cow dung with forest soil to form a nutrient rich growth media. Using forest soil;sawdust, cow dung and mixture of these components, this study sought to determine growth characteristics of Eucalyptus saligna seedlings under different conditions available in the nursery. The experiment was laid out in a Completely Randomized Design (CRD) with six treatments comprising of Saw dust alone (Tr 1), Forest soil alone (Tr 2);Sawdust: Cow dung mixture in the ratio of 1:1 (Tr 3);Forest soil to Sawdust-Cow dung mixture (1:1) in ratio of 1:1 by weight (Tr 4);Forest soil to Sawdust-Cow dung mixture (1:1) in ratio of 1:2 by weight (Tr 5) and Forest soil to Sawdust-Cow dung (1:1) in ratio of 1:3 by weight (Tr 6). Treatments were replicated three times and an experimental unit consisted of 110 seedlings of which 15 were tagged for height and root collar diameter measurement. The remaining 95 were used for biomass determination by destructive sampling. The results showed that Sawdust: Cow dung mixtures (Tr 3) had the highest measurements for height, root collar diameter and biomass at week 20 when compared to the rest of growth mixtures. Height measurements were significantly high (13.81 cm) for the Sawdust: Cow dung mixtures while the variation in root collar diameter and biomass were not significantly different among the treatments. Sawdust alone did not favor seedling growth and recorded the lowest measurements in height, root collar diameter and biomass. Nutrient release from the growth media during the experimental period was equally high for the Saw dust: Cow dung mixture (Tr 3) which was ideal media for raising tree seedlings. The findings of this study illustrate the usability of sawdust and cow dung in enhancing the productivity of tree nurseries and shortening the time taken for raising seedlings in the tree nursery. The findings also propose a safe disposal of saw dust that poses as an environmental waste.

Estimation of Tree Height and Forest Biomass Using Airborne LiDAR Data: A Case Study of Londiani Forest Block in the Mau Complex, Kenya

Tactical decisions on natural resource management require accurate and up to date spatial information for sustainable forest management. Remote sensing devices by the use of multispectral data obtained from satellites or airborne sensors, allow substantial data acquisition that reduce cost of data collection and satisfy demands for continuous precise data. Forest height and Diameter at Breast Height (DBH) are crucial variables to predict volume and biomass. Traditional methods for estimation of tree heights and biomass are time consuming and labour intensive making it difficult for countries to carry out periodic National forest inventories to support forest management and REDD+ activities. This study assessed the applicability of LiDAR data in estimating tree height and biomass in a variety of forest conditions in Londiani Forest Block. The target forests were natural forest, plantation forests and other scattered forests analysed in a variety of topographic conditions. LiDAR data were collected by an aircraft flying at an elevation of 1550 m. The LIDAR pulses hitting the forest were used to estimate the forest height and the density of the vegetation, which implied biomass. LiDAR data were collected in 78 sampling plots of 15 m radius. The LiDAR data were ground truthed to compare its accuracy for above ground biomass (AGB) and height estimation. The correlation coefficients for heights between LiDAR and field data were 0.92 for the pooled data, 0.79 in natural forest, 0.95 in plantation forest and 0.92 in other scattered forest. AGB estimated from LiDAR and ground truthed data had a correlation coefficient of 0.86 for the pooled data, 0.78 in natural forest, 0.84 in plantation forest and 0.51 in other scattered forests. This implied 62%, 84% and 89% accuracy of AGB estimation in natural forests, other scattered forests and plantation forests respectively. The even aged conditions of plantation forests might have resulted to better estimates of height and AGB as compared to uneven aged natural forests and scattered forests. The results imply the reliability of using Airborne LIDAR scanning in forest biomass estimates in Kenya and are an option for supporting a National Forest Monitoring System for REDD+.

Assessment of the Effectiveness of Watershed Management Intervention in Chena Woreda, Kaffa Zone, Southwestern Ethiopia

The main purpose of this study was to assess the effectiveness of watershed management intervention in Chena Woreda. A systematic sampling technique was used to select sample micro-watersheds, and random sampling method was used to select individual households from both intervention and non-intervention areas. Data were collected through field observation, household questionnaire survey, focused group discussion, in-depth interview and key informant interview. Moreover, physical soil and water conservation structures’ layout measurement was conducted. Descriptive statistics, t-test, chi-square test and participation index were used for data analyses. The study revealed that the intervention has good achievements in reducing soil erosion, improving water availability and quality, developing tree plantation and diversifying household income sources in the catchment. However, poor community participation, lack of the structures design alignment with standards, inappropriate time of implementation, lack of diversified soil water conservation measures, absence of regular maintenance and management of the structures were some of the major limitation of the intervention. Therefore, this study recommends that the stake-holders should make appropriate correction measures for observed failures and further interdisciplinary study should be conducted to explore the problems.

Comparing Tree Heights among Montane Forest Blocks of Kenya Using LiDAR Data from GLAS

This study was designed to use LiDAR data to research tree heights in montane forest blocks of Kenya. It uses a completely randomised block design to asses if differences exist in forest heights: 1) among montane forest blocks, 2) among Agro ecological zones (AEZ) within each forest block and 3) between similar AEZ in different forest blocks. Forest height data from the Geoscience Laser Altimeter System (GLAS) on the Ice Cloud and Land Elevation Satellite (ICE-SAT) for the period 2003-2009 was used for 2146 circular plots, of 0.2 - 0.25 ha in size. Results indicate that, tree height is largely influenced by Agro ecological conditions and the wetter zones have taller trees in the upper, middle and lower highlands. In the upper highland zones of limited human activity, tree heights did not vary among forest blocks. Variations in height among forest blocks and within forest blocks were exaggerated in regions of active human intervention.

An annotated checklist of mammals of Kenya

Kenya has a rich mammalian fauna. We reviewed recently published books and papers including the six volumes of Mammals of Africa to develop an up-to-date annotated checklist of all mammals recorded from Kenya. A total of 390 species have been identified in the country, including 106 species of rodents,104 species of bats, 63 species of even-toed ungulates(including whales and dolphins), 36 species of insectivores and carnivores, 19 species of primates,five species of elephant shrews, four species of hyraxes and odd-toed ungulates, three species of afrosoricids, pangolins, and hares, and one species of aardvark, elephant, sirenian and hedgehog. The number of species in this checklist is expected to increase with additional surveys and as the taxonomic status of small mammals(e.g., bats, shrews and rodents) becomes better understood.

Characterization of Forest Degradation beyond Canopy Cover Change in Mau Forest, Kenya

Monitoring Forest degradation is evidence enough to show a country’s commitment to monitor the forest trend both for national and local decision-making and international reporting processes. Unlike deforestation which is easier to point out, monitoring forest degradation is quite a challenge since there is no universal definition and thus no clear monitoring methods apart from the canopy cover change. This research, therefore, sought to look at the degradation trends in the Mau forest complex between 1995-2020 with the aim of finding out whether monitoring canopy density changes over time and quantifying these changes in terms of biomass loss could be a good approach in monitoring forest degradation. Forest Canopy Density (FCD) model was adopted focusing on using vegetation indices describing biophysical conditions of Vegetation, Shadow and Bareness to monitor changes in canopy density as a parameter for describing forest degradation in the forest blocks of Maasai Mau and Olpusimoru in Mau forest complex. Results indicated how different vegetation indices responded to changes in the vegetation density and eventually changes in the canopy density values which were converted in terms of biomass loss. The forest Canopy Density model proved to be a good tool for monitoring forest degradation since it combines different biophysical indices with different characteristics capturing what is happening below the canopy.

Human-climate induced drivers of mountain grassland over the last 40 years in Sidama, Ethiopia: perceptions versus empirical evidence

Background:Mountain grasslands are globally important ecosystems.They are considered as heritage sites with“outstanding values”to ecological communities by adding a further“layer and support to the existing protection measures.”However,mountain grasslands are increasingly under threat from human activities and impacts of climate change.Methods:Using satellite imagery,we studied land use/land cover(LULC)patterns between 1973 and 2015.Individual interviews consisting of 240 households for comparison and field data collection were conducted for accuracy assessment.Results:Five categories of LULC types were identified from the image classification that included forestland,grassland,shrubland,bushland,and agricultural land.Between 1973 and 2015,the forestland,grassland,and shrubland covers were declined by 15.9%,53.6%,and 41.0%,respectively.In contrast,bushland and agricultural land were increased by 169%and 647%,respectively.The overall LULC classification accuracies for the four reference years ranged from 77.6 to 86.5%with Kappa statistic of 0.69 to 0.80.The majority of respondents(92.5%)mentioned that the cover of forestland outsized the other land use land cover types followed by grassland in the past.Conclusions:The stated indicators of land use/land cover changes linked to the impact of climate change were decline in milk yield and crop production,spread of livestock diseases,degradation of grazing lands,and change in the timing of rain.The results of the study suggest that human-climate related components were major drivers of land use/land cover dynamics that demand for proper management and conservation of mountain grassland ecosystem in Sidama South Ethiopia.

Seed dispersal by Tana River mangabeys in fragmented gallery forests

Data collected on a free ranging group of Tana River mangabeys (Cercocebus galeritus) indicates that this endangered primate species, which has previously been regarded as a seed predator, plays an important role in seed dispersal and do contribute to the regeneration of a highly fragmented gallery forest. We observed fruit handling behavior and the post-dispersal fate of seeds ingested by the mangabeys. The two main fruit handling behaviors observed, fruit swallowing and processing fruits in cheek pouches, positively contributed to seed disper- sal. Seed predation was not common during this study, apart from a few particular plant species such as Acacia robusta and Alangium salviifolium with non-fleshy fruits. We found a correlation between seed predation and fruit availability, respectively seasonal differential specific dispersal efficiency. The role of the mangabeys in dispersing seeds and facilitating forest regeneration is enhanced by their movement across forest patches through non-forested matrix, which contributes to the deposition of seeds and regeneration in these habitat gaps.