Melliferous taxa, floral calendar, Melissopalynology, and organoleptic characterization of aboriginal Ogiek honey in the eastern Mau forest block, Kenya

Abstract

Mau forest is one of the five water towers in Kenya serving as a critical catchment area for rivers and lakes in both Kenya and Tanzania. It plays a critical role in livelihood support. Eastern Mau forest has experienced most of the deforestation, loss of ecosystem vitality and biodiversity due to non-inclusion of local community in the conservation efforts. The Kenyan government legislative and policy frameworks have acknowledged the need for involvement of the Ogiek community. The community have long lived in the forest and area knowledgeable in forest conservation and bee keeping. Beekeeping by the Ogieks has been recommended under livelihood support programs to reduce destructive forest exploitation, this is by lack of information on: the authenticity of botanical and geographical origin of the Ogiek honeys, floral calendars to enhance apiary management and, organoleptic profile to enable sale in regulated honey markets. The objective of this study was to characterize melliferous flora, the botanical and geographical origin of Ogiek honeys and their organoleptic profile. A simple stratified random sampling research design was adopted with Kapkembu, Nessuit, and Mariashoni areas, Eastern Mau as the strata. The Ogiek bee keepers’ hives were the source of honey samples. Ten grams of each of the twenty-seven honey samples collected from Eastern Mau forest formed the unit of analysis. Approved methods of honey analysis were used. Collection of field data for development of floral calendar adopted belt transects around selected bee colonies for twelve months. Data was subjected to Analysis of Variance, Tukeys honestly significant difference post-hoc test, multivariate analysis, Jaccards similarity coefficient, quantitative descriptive analysis, and two-step cluster algorithms on SPSS base 20. Means of organoleptic data was subjected to Friedman’s test. Total of eighty-six plant species are foraged by Apis mellifera. Cissus rotundiflora Vahl. (Vitaceae), Trema orientalisL. (Ulmaceae), Maerua triphyllaA. Rich (Capparaceae), Aloe secundiflora Engl. (Asphodelaceae), Tribulis terrestisL. (Zygophyllaceae) and Polyscias fulvaJ.R. Forst. and G. Forst. (Araliaceae) are reported for the first time in Eastern Mau. Trees formed 41.86%, Herbs (25.58%), Shrubs (23.25%), and climbers (9.3%) of the bee forage. The peak availability of forage from the floral calendar was in April and May (2016) during the study. The Acacia species provide successive bloom mosaic year round. The highest similarity was observed in a comparison between (NE-S3-8) and NE-S1-8) within same site. The mean number of pollen types were highest in April (12.8), and lowest in December (9.7). There is a significant positive correlation (r=0.607*, 0.05) between number of pollen types and pollen density. Mean Shannon weaver diversity index was 2.32 across all seasons and sites of sample collection. Vernonia auriculifera, Cordia abyssinica, Acacia spp were very frequent pollen types, with Acacia type pollen having 85.2% frequency of occurrence in the honey samples. The rare, infrequent, frequent, very frequent pollen types observed in this study constitute the pollen spectrum that determine the geographical origin of Ogiek honeys in Eastern Mau forest. Botanical origin from predominant pollen types were Acacia spp type, Eucalyptus type, Croton spp. type, Albizia coriaria type, Cordia abyssinica type, and Vernonia auriculifera type. Floral fresh aroma family was the most dominant in 50% of the unifloral honey samples represented by Acacia, Croton and Albizia honey. Friedman’s test (N=12, df=7, X2 =14.07, Least Significant Difference= 23.52) revealed a significant difference in the sum of rankings in all organoleptic attributes. This study provides significant information on the floral calendar, unifloral and multifloral botanical origin as well as pollen spectrum denoting the geographical origin, and an organoleptic profile of unifloral Ogiek produced honeys Eastern Mau. The information from this study is important for extension services and policy development.