An assessment of manganese distribution in podzols, brown earth, gley, and peat soils in NE Scotland showed that most of the manganese was in a form unavailable to plants (residual manganese). Among the available forms, exchangeable manganese in litter had by far the largest concentration. The percentage of total manganese in the exchangeable form in forest soils was found to have a very good correlation with organic matter concentration. Manganese oxides made a negligible contribution to the available manganese pool. It is believed that their supply is limited due to dissolution. Heather litter was found to contain larger concentrations of total manganese than forest litter. However, exchangeable manganese is lost easier from heather litter than forest litter, probably through leaching. A slow equilibration technique was applied to obtain Langmuir adsorption isotherms for manganese in simulated throughfall and Sitka spruce litter. It showed that the maximum adsorption capacity of litter reached a value of many thousands mg kg<SUP>-1</SUP>. Competition between hydrogen and manganese ions in simulated throughfall for adsorption sites on Sitka spruce litter was examined. It was found that the more acid treatments can leach significantly more manganese; however, exchangeable manganese is influenced by manganese concentration in throughfall and can increase in concentration proportionally to the manganese content in throughfall. It is believed that this is a defensive mechanism against excess manganese leaching from litter. A simulated acid rain experiment involving reconstituted soil profiles and young Sitka spruce trees was set up to investigate manganese fluxes and manganese cycling in the microcosms thus created.

Given the overexploitation of indigenous forests and inadequate regeneration programmes in Peninsular Malaysia there is concern about the long term availability of both export grade timber species and low grade timber for domestic consumption. Therefore heartwood samples from seven species with commercial potential, (kapur (<i>Dryobalanops aromatica</i> Gaertn. f); kempas (<i>Koompassia malaccensis</i> Maing. ex Benth); keruing (<i>Dipterocarpus</i> spp.); mersawa (<i>Anisoptera</i> spp.); punah (<i>Tetramerista glabra</i> Miq.); rubberwood (<i>Hevea brasiliensis</i> Muell.-Arg) and simpoh (<i>Dillenia</i> spp.)) but about which there exists little objective information were evaluated in terms of their preservation characteristics. The species' inherent structural limitations to impregnation were water-borne copper-chrome-arsenic (CCA) preservatives were identified through the use of both optical and scanning electron microscopy. Samples of each species were evaluated for their amenability to fluid impregnation through the use of a novel technique which allowed for the direct and continuous measurement and observation of fluid uptake throughout a controlled vacuum-pressure treatment cycle. The technique provided quantitative data on species amenability to impregnation and also allowed for the determination of optimum process duration. The evaluation of preservative active ingredient distribution in treated samples was determined qualitatively through the use of colorimetric reagents and scanning electron microscopy energy dispersive X-ray microanalysis and quantitatively through the use of X-ray fluorescence spectrophotometric analysis. These studies highlighted preservative distribution problems in several of the species examined most notably kapur, kempas, rubberwood and mersawa.

No description available.

This study, conducted in Indian Western Himalaya, investigated factors affecting tree growing in traditional agroforestry systems and the perspective of women and forestry staff towards agroforestry. Many physical, socio-economic, forest resource use and perceptional factors influenced tree growing. Forestry related factors were found through logistic regression to be weak determinants of tree growing. Farm size, traditional farm fencing agroclimatic zone and soil fertility were the important physical determinants. Worship of holy trees, importance of tree growing for future generations, mobility of head of household and family literacy were important social determinants. Agricultural production, off-farm income and restriction on grazing on-farm were important economic factors. The key forest resource use factors affecting agroforestry adoption were previous participation in forestry programmes, primary source of fuelwood, extent of natural regeneration and distance travelled to collect fuelwood. The perception about restriction on felling trees from their own farm and attitude towards agroforestry were key perceptional factors. Women’s decision to grow trees was nested within the overall household’s decision whether to grow trees. In tree-grower households, women grew trees to meet their own and overall household interest. In contrast to expectations, women preferred growing trees for fruits over fuelwood. The dilemma of foresters in properly identifying the issues related to on-farm tree growing was due to their conflicting roles as members of the local society on the one hand and foresters on the other. From the perspective the restriction on felling farm trees and selling them in the market was the most important constraint on tree growing. They preferred provision on incentives for tree growing as the most important motivator. Agroforestry training was concentrated on nursery and plantation management but they now recognise they need training in extension and agricultural aspects of agroforestry. Efforts to encourage tree growing should not merely consider on-farm tree growing in isolation of on-farm and off-farm affecting livelihoods of farmers.

No description available.

No description available.

No description available.

I assessed the effects of understorey cultivation of cardamom (<i>Eletteria cardamomum) </i>on forest structure, tree species composition, soil properties and potential for regeneration in the Knuckles Forest Reserve (KFR) in central Sri Lanka through extensive vegetation and soil sampling. In addition, I examined practical techniques for restoring forests affected by cardamom cultivation through experimental manipulations. Forests with cardamom (cardamom plantations) had higher canopy openness and lower tree, sapling and seedling densities than adjacent forests without cardamom (natural forests). Overall, cardamom plantations tended to be more diverse than natural forests, mainly related to the addition of pioneer species. Cardamom plantations had higher concentrations of total P and exchangeable K but lower concentrations of total N and soil pH than the natural forests. Relative to natural forests, cardamom plantations had a higher density of seed in the soil seed bank, with a higher percentage of grass and non-native species. Experimental manipulations in cardamom plantations demonstrated that slashing or uprooting or weeding of cardamom stands enhances tree seedling recruitment over the first 15 months post-treatment. However, given the higher labour costs required for removal of cardamom plants, deliberate weeding of cardamom stands with minimum disturbance to tree seedling emergence may be sufficient to enhance tree regeneration in cardamom plantations. Stakeholders in the Knuckles Forest Reserve have mixed views about the rationality of prohibiting cardamom cultivation in the reserve and forests in the buffer zone. However, there are the opportunities for enhancing cardamom production in agroforestry systems outside the reserve.

No description available.

No description available.