Latest News on Forest Reserve : April 21

[1] Land‐use and cover changes (1988–2002) around budongo forest reserve, NW Uganda: implications for forest and woodland sustainability

Land‐use and cover changes around Budongo Forest Reserve (BFR) were analysed from multi‐temporal LandSat images (1988 and 2002) and associated field‐based studies in 2003–2004. Three major land‐use and cover classes: forest/woodland, sugarcane plantations and grassland/shifting‐cultivation/settlements were clearly discriminated. The area under sugarcane cultivation increased over 17‐fold, from 690 ha in 1988 to 12729 ha in 2002, with a concomitant loss of about 4680 ha (8·2 per cent) of forest/woodland, mainly on the southern boundary of BFR. Land‐use and cover changes were a result of (a) agricultural expansion, (b) increasing human population, exacerbated by large influxes of refugees, (c) conflicts of interest and political interference in the management of BFR and (d) unclear land tenure. Agriculture is the main land‐use practice and source of income to local people, with commercial sugarcane and tobacco as the primary cash crops. Individual smallholder sugarcane plantations covered distances ranging from 30 to 1440 m along the BFR edge, with no buffer zone, resulting in direct conflicts between farmers and forest wild animals. There is an ever‐increasing need for more land for agricultural expansion, resulting in continued loss of forest/woodland on private/communal lands and encroachment into BFR.

[2] Changes following 60 years of selective timber harvesting in the Budongo Forest Reserve, Uganda

The controlled extraction of timber from the Budongo Forest Reserve began in the 1930s. From the start of the operations it was intended that the timber should be harvested on a sustainable yield basis and the first of several 10-year working plans for the forest was drawn up in 1933. This paper documents the volume of timber removed, the date of logging, date of arboricide treatment and volume of arboricide applied in most compartments in the forest. Four species of mahogany formed about 65% of the timber extracted and this remained almost constant over the years despite attempts to encourage the use of other species by the Uganda Forest Department. Forest type maps made from sets of aerial photographs taken in 1951 and 1990 showed an increase in ‘mixed forest’ at the expense of ‘Cynometr forest’; one of the major aims of the arboricide treatment.

[3] The diversity, abundance and biomass of termites under differing levels of disturbance in the Mbalmayo Forest Reserve, southern Cameroon

This paper presents data on the abundance, biomass and species richness of termites in the Mbalmayo Forest Reserve, southern Cameroon. Five plots of differing disturbance level (near primary forest, old secondary forest, young plantation, weeded Chromolaena fallow, and completely cleared forest) were sampled for termites in two successive years (July 1992 and July 1993, giving a total of ten sampling areas, plus one in the completely cleared plot in November 1992). A stratified sampling regime of soil pits, wood samples, mound samples and soil scrape samples was used. Estimated abundance and biomass were extremely high in the near primary and old secondary plot (maximum estimated abundance, old secondary sampling area 1, 10488 m-2, maximum biomass density, near primary sampling area 1,123.2 g m-2). In all cases termite abundance was highly clumped. Disturbance had apparently little effect on termite abundances and biomass in forested plots, but there were clear reductions in abundance and biomass in the cleared plots. In the completely cleared plot, abundance and biomass fell sharply from year 1 to year 2, presumably because colonies left after clearance had dried out and died.

[4] Height-diameter Relationship Models for Teak (Tectona grandis) Plantation in Nimbia Forest Reserve, Nigeria

The study on height-diameter modelling was carried out on Teak (Tectona grandis) plantation in Nimbia Forest Reserve. Two fit methods (Chapman-Richards and Weibull) were used to model height-diameter relationship. The teak plantation is divided into four forest beats as management unit, therefore, stratified random sampling was employed to select five plots of 20 x 20 m from each forest beat (as stratum), thereby having a total of 20 plots. Stump diameter (Dst), diameter at breast height (Dbh), diameter at middle and top positions (Dm and Dt) of trees, and tree height for all the selected trees were measured. Average Dbh measured 15.00 cm and the mean tree height was 6.77 m. Pseudo coefficient of determination (Pseudo R2) and residual mean square error (RMSE), goodness-of-fit statistics were considered as model selection criteria. Chapman-Richards function produced the best goodness-of-fit statistics for Teak height-diameter modelling. The height-diameter models require additional site factors for better models; hence the need for establishing permanent sample plots (PSP) in order to get additional information from re-measurements of the plots.

[5] Tree Species Diversity and Structure of Eda Forest Reserve, Ekiti State, Nigeria

Tropical rainforest is continuously threatened by timber exploitation and conversion to other land uses. In this study, tree species diversity and forest structure of Eda Forest Reserve in Ekiti State, Nigeria, were assessed using systematic line transect and purposive sampling techniques for plot demarcation and data collection. Two transects (2000m long) were laid in secondary forest and encroached farmland in the reserve, while the primary forest fragments were sampled purposively. Twenty sample plots (20m×20m) were laid out on each of the vegetation types. All trees >10cm diameter at breast height (dbh) were identified to species level and enumerated for total height and dbh. Data were analyzed using descriptive statistics such as tables, charts, frequency, percentages and diversity index analysis using paleontological statistics software (PAST 2.14). There were 60 species from 22 families, with Sterculiaceae, Caesalpiniaceae and Moraceae being the most abundant families. Individual tree populations were 380 trees/ha, 280 trees/ha and 137 trees/ha in the primary forest, secondary forest and encroached farmland, respectively.

 

Reference

[1] Mwavu, E.N. and Witkowski, E.T.F., 2008. Land‐use and cover changes (1988–2002) around Budongo forest reserve, NW Uganda: Implications for forest and woodland sustainability. Land degradation & development19(6), pp.606-622.

[2] Plumptre, A.J., 1996. Changes following 60 years of selective timber harvesting in the Budongo Forest Reserve, Uganda. Forest Ecology and Management89(1-3), pp.101-113.

[3] Eggleton, P., Bignell, D.E., Sands, W.A., Mawdsley, N.A., Lawton, J.H., Wood, T.G. and Bignell, N.C., 1996. The diversity, abundance and biomass of termites under differing levels of disturbance in the Mbalmayo Forest Reserve, southern Cameroon. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences351(1335), pp.51-68.

[4] Shamaki, S.B., Akindele, S.O., Isah, A.D. and Mohammed, I., 2016. Height-diameter relationship models for Teak (Tectona grandis) plantation in Nimbia Forest Reserve, Nigeria. Asian Journal of Environment & Ecology, pp.1-7.

[5] Olajuyigbe, S.O. and Jeminiwa, M.S., 2018. Tree species diversity and structure of Eda forest reserve, Ekiti State, Nigeria. Asian Journal of Research in Agriculture and Forestry, pp.1-12.

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