The faint promise of a distant market: a survey of Belém's trade in non-timber forest products

Increased trade in non-timber forest products (NTFPs) has been promoted as one possible means to slow tropical deforestation by increasing the economic value of intact forest. A market survey of NTFPs occurring in the Capim River basin in eastern Amazonia, Brazil demonstrated that the reality for many smallholder communities in frontier and remote regions includes chronic transportation difficulties, high variability in fruit production, perishable products and lack of market expertise. In some communities, declining abundance of NTFPs due to logging and fire has resulted in a lack of forest products to even meet subsistence needs. In areas close to cities where transportation is assured and where forest clearing has eroded the natural occurrence of some valuable native NTFPs, smallholders who manage and successfully market native fruit and medicinal species are overcoming these obstacles. In frontier regions undergoing rapid transformation, however, decline in locally used and regionally marketed NTFPs currently pose detrimental consequences for communities. Findings suggest that an overemphasis on NTFP marketing has diverted attention from local livelihood, resource access and subsistence issues.     

The natural regulation of Giant tortoise populations on Aldabra Atoll. Reproduction

A two-year reproduction study of three isolated populations of different densities of the Aldabra Giant tortoise ( Geochelone gigantea Schweigger) showed dissimilarity in gonadal parameters; (i) as population density increased age at sexual maturity was delayed in males and females; (ii) although the mean number of mature follicles was similar in all populations, preovulatory follicular atresia was only found in the high density population; (iii) annual variation in preovulatory follicular atresia was dependent on rainfall and food availability; (iv) the number of clutches laid/♀/year decreased with increasing population density as did clutch size; in the high density population (and depending on rainfall) only 30–80% of the mature females bred. The discussion considered the importance of movement in determining survival/reproduction.     

Sex ratio under conditional sex expression

We present a model to show that, when sex depends on environment rather than genotype, the sex expressed under relatively unfavorable conditions will be more abundant. This result refers to numbers of males and females in the population. By contrast, no clear prediction can be made about the allocation of resources to the two sexes. The model is constructed to highlight the logical relationship between the distribution of resources to the two sexes and the relative numbers of males and females. The predicted bias in numbers toward the sex developing under unfavorable conditions depends on the assumption that fitness either increases or decreases steadily according to the quantitative variable on which sex expression depends.     

Manipulation of vegetation communities on the Abu Dhabi rangelands. II. The effects of topsoiling and drip irrigation

The effect of topsoiling on the vegetation communities of Abu Dhabi coastal desart rangelands with sand taken from an inland area of rangeland supporting a different vegetation community, was investigated. The study was carried out on ghanada Island, an inshore desert island which had been extensively topsoiled in the previous 5 years. Parts of the island also had been drip irrigated. Perennial vegetation communities on Ghanada were markedly different on topsoiled areas compared to non-topsoiled areas. However not all the species common in the topsoil source area were subsequently found to be common on the topsoiled areas. Zygophyllum hamiense, thought to be a colonizer of disturbed soil in the source areas, was common on the topsoiled areas. Annual plant species richness was greater on topsoiled areas compared to untreated native soil indicating (i) that the source areas had a greater annual species richness than Ghanada, and (ii) annual species propagules successfully survived the processes of topsoiling. Annual and perennial species richness was not significantly different between irrigated and non-irrigated areas. The perennial percentage cover was greatest on drip irrigated areas and the perennial which benefited the most was Heliotropium kotschyi, probably due to its rhizomous growth habit.     

Extinction Risk: Predicting and Redressing the Threat

Predicting and redressing the threat of species extinction is not a success story. The science of estimating extinction rates and risk prediction is approached in a manner that is difficult to apply in the field, and yet current integrated ecosystem management programmes in many parts of the world, which are trying to place the conservation of species into sustainable community projects, need predictive tools for planning land use programmes. Such programmes involve US$100s of millions of multilateral and bilateral aid; many predicated on a site's biodiversity importance, the risks of extinction, sustainable extraction, production forms of land use, community livelihoods, water, and many others factors, but increasingly on ensuring that after the pump-priming funds are finished the programmes are both environmentally and economically sustainable (Swingland 2002, 2003, 2004; Swingland et al. 2003). [Swingland I.R. 2002. In: Swingland I.R., Bettelheim E.C., Grace J., Prance G.T. and Saunders L.S. (eds), Carbon Biodiversity, Conservation and Income: An Analysis of a Free Market Approach to Land-use Change and Forestry in Developing and Developed Countries. Philosophical Transactions Royal Society London A: Mathematical, Physical and Engineering Sciences, London; Swingland I.R. (ed.) 2003. Capturing Biodiversity and Conserving Biodiversity: The Market Approach. Earthscan, London; Swingland I.R. (ed.) 2004. CO² e biodiversità. Un approccio integrato a favore del clima e del patrimonio naturale. Edizioni Ambiente, Milano, Italy, 296 pp.; Swingland I.R., Bettelheim E.C. and Niles J.O. 2003. In: Swingland I.R. (ed.), Capturing Biodiversity and Conserving Biodiversity: The Market Approach. Earthscan, London] This involves predictions of ‘what if?’ what if laws are changed to prevent over utilisation and prevent ‘The Tragedy of the Commons’ where land ownership is vested in the state and people degrade the environment, and instead institute private land ownership. In places like China and much of the Far East, biodiversity is over-exploited as nearly all their species are used for food, medicine and construction purposes, and private land ownership in rural areas is rudimentary or absent. Since most species extinction is anthropocentric, research on species extinction needs to be more accessible and focussed on global problems.     

Genetic divergence and units for conservation in the Komodo dragon Varanus komodoensis

In the past decade much attention has focused on the role that genetics can play in the formation of management strategies in conservation. Here, we describe genetic diversity in the world''s largest lizard, the Komodo dragon (Varanus komodoensis), examining the evolutionary relationships and population genetic history of the four islands in south-east Indonesia, which form the vast majority of its range. We identify distinct genetic groups for conservation. The population on the island of Komodo shows by far the largest values of genetic divergence and is proposed that it should be a separate conservation management unit. Other populations, surviving either on small islands with substantially reduced genetic variability, or in isolated patches, are identified as particularly vulnerable to stochastic threats and habitat loss. Our results provide an example of how data defining intraspecific levels of genetic divergence can provide information to help management plans, ensure the maintenance of genetic variability across populations and identify evolutionary potential within endangered species.     

Manipulation of vegetation communities on the Abu Dhabi rangelands. I. The effects of irrigation and release from longterm grazing

The effect on vegetation communities of release from grazing by camels and goats has been investigated in the Baynunah region of Abu Dhabi emirate, in The United Arab Emirates, by the study of an exclosure established 11 years previously. Also the effect of sprinkle irrigation (in the absence of grazing) on the rangeland vegetation was investigated. Perennial species richness was significantly lower outside the exclosure compared with inside on both sand and gravel substrata. Annual species richness however was not significantly different. Perrenial percentage covers were lower outside the exclosure compared with inside, especially on sand substrata. The perennial grass Stipagrostis plumosa (L) showed the greatest difference in percentage cover in this respect. The species richness of annuals and perennials was not significantly different between irrigated and non-irrigated areas within the exclosure. The perennial percentage cover was much greater on sprinkle irrigated sand and gravel substrata. The perennial which benefited the most was Zygophyllum hamiense, Scweinf. Annual percentage cover was lower in irrigated quadrats. Suggestions are made about the effect of intensive grazing on the vegetation communities at Baynunah and on the effectiveness of irrigation as a tool for increasing the quality of the rangeland for livestock and wildlife.     

The influence of light intensity on the roosting times of the rook (Corvus frugilegus)

Little work has been done on the roosting behaviour of Corvidae, particularly the influence of light-intensity on its timing. This paper describes the effects of light-intensity on the roosting times of rooks (Corvus frugilegus) from a large roost during winter. Light intensity was measured and its influence on the departure of birds from the feeding grounds, arrival at the roost, entry into the roost and morning departure was found to be significant. Departure from feeding areas (and arrival at the roost) was earlier at lower light-intensities and later at higher light-intensities. Control of responsiveness to light-intensity by circadian rhythm for rooks from different feeding grounds was discussed.