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Society for Conservation Biology: 2002 Annual Meeting

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Society for Conservation Biology: 2002 Annual Meeting

Society for Conservation Biology 16th Annual Meeting July 14-July 19 2002
co-hosted by DICE and the British Ecological Society


Abstracts for Sustainable Resource Use
Session One

Tuesday 16th July, 13.30 - 15.00, Grimond Lecture Theatre 1

Chair: Richard Bodmer




(BLOCK CAPITALS indicate the presenting author)


13.30 - 13.45
PFAB, MICHÈLE F. and Mavis A. Scholes. Gauteng Department of Agriculture, Conservation, Environment and Land Affairs, P.O. Box 8769, Johannesburg, 2000, Gauteng, South Africa, <MicheleP@GPG.gov.za> (MP), 20 Gavin Avenue, Pine Park, 2194, Gauteng, South Africa (MS).

IS SUSTAINABLE USE ACHIEVABLE? THE CASE OF ALOE PEGLERAE.

Introduced by the Convention on Biological Diversity, the concept of sustainable use is widely accepted by the authorities and public of South Africa. However, the concept is rarely challenged. Aloe peglerae, an Endangered species restricted predominantly to the Magaliesberg range of South Africa, is threatened mainly by illegal collection. A population of 110 individuals was monitored demographically from 1976 to 1995. Resulting data were used to determine the temporal variation in observed demographic and reproductive parameters on which a stochastic population model was based. The model was used to assess the long-term effects of harvesting both adult plants and seed. Use of A. peglerae populations was found to be sustainable at only very low levels. Between 0.10% and 0.12% of an adult population can be harvested annually, equivalent to harvesting one plant every year from a large population of at least 1000 adults or one plant every 10 years from a population of 100 adults. With annual harvesting of one plant each year, a population of 250 adults or less has at least a 96% probability of becoming extinct within the next 500 years. However, a maximum of fifteen percent of the annual seed output can be harvested sustainably.

13.45 - 14.00
BENNETT, SARITA JANE. Co-operative Research Centre for Plant-based Management of Dryland Salinity, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia, <sarita@cyllene.uwa.edu.au>.

THE SEARCH FOR NATIVE PLANTS TO SLOW THE RISE OF DRYLAND SALINITY IN LOW-RAINFALL AREAS OF SOUTHERN AUSTRALIA

Dryland salinity is the response of the environment to the large-scale clearance of native vegetation and its replacement with annual crops. This has resulted in a water imbalance, with not all rainwater entering the system being utilised, subsequently raising the watertable and transporting salt from ancient saltpans to the surface. Legume pastures have traditionally been developed from Mediterranean species. However, Australia has a very rich native diversity, including many legume species. The aim of this study is therefore to conduct an ecogeographic survey to determine a number of native perennial legume species that are already well adapted to the climatic and edaphic conditions of southern Australia. The ecogeographic survey was conducted using the geographical information system, ArcView, and the climate modelling program CLIMEX, plus information from floristic guides in each state. A number of species from the genera Swainsona, Lotus, Glycine, Kennedia and Cullen have been identified that have similar climatic and edaphic requirements to the target areas in southern Australia. The advantage of using native species, such as these, is that they are deep-rooted and summer active, and so are able to utilise water stored in the soil profile during the summer months when annual agricultural species are absent.



14.00 - 14.15
BITARIHO, ROBERT, Alastair McNeilage, Dennis Babaasa and Aventino Kasangaki. Institute of Tropical Forest Conservation, P.O. Box 44, Kabale, Uganda, <itfc@infocom.co.ug>.

HARVEST IMPACTS OF PLANTS FROM BWINDI IMPENETRABLE NATIONAL PARK, UGANDA, BY LOCAL COMMUNITIES

Sustainable utilisation of forest resources has been widely adopted as a conservation strategy, but that sustainability has rarely been empirically tested. Plant resource extraction from Bwindi Impenetrable National Park by local communities has been legalised and controlled in specific multiple use areas. We undertook to determine harvest impacts of plant resource extraction, and to monitor long-term changes of plant extraction. We prioritised three species, Rytigynia spp., Ocotea usambarensis and Loeseneriella apocynoides, that are highly demanded and vulnerable to overexploitation. We used forest surveys to assess plant density and distribution as well as forest user society records to assess plant resource offtakes. Early results indicate that Loeseneriella has experienced severe harvest impacts. Over 80% of the plants are seedlings and there are very few harvestable mature stems, indicating overexploitation. Over 70% of Rytigynia and Ocotea harvested for bark are mature trees, and there are indications of poor regeneration. Forest society offtake records show a gradual decline in plant resource harvesting. The harvesting of Loeseneriella in the park should be halted. Long-term studies of the population dynamics and biomass production of the bark of Rytigynia and Ocotea is ongoing, to determine the harvest impacts and sustainable harvest levels.



14.15 - 14.30
DU PLESSIS, MORNE A. and Christian Boix-Hinzen. Percy FitzPatrick
Institute, Centre of African Conservation Biology, University of Cape Town,
Rondebosch, South Africa, <morne@botzoo.uct.ac.za>.

FUELWOOD COLLECTION PRESSURE CAN LEAD TO LOCAL EXTINCTIONS OF CAVITY-USING BIRDS IN SOUTH AFRICA

Energy is a limiting commodity for many communities in the developing world and the rural communities of Africa are highly dependent upon wood as their primary source of energy. Fuelwood collection does, however, affect the vertebrate communities that live in exploited habitats. Two studies in southern Africa have revealed that excessive levels of fuelwood collection in concentrated areas can lead to either localised extinctions of some cavity-using bird species, or a reduction in the densities of birds. Over a period of 20 years, three cavity-using bird species disappeared from heavily utilised riverine forests at a site in South Africa. These species included both primary and secondary cavity users. In a study in Namibia, dead wood was found to be ten times more common in lightly versus heavily harvested areas. In these sites, over half of cavity-using species had disappeared from heavily used areas. Most striking of all was that transects in heavily harvested sites yielded 77% fewer birds (29.2 vs. 9.7) than lightly harvested sites.



14.30 - 14.45
GROS, PAULE, Cheryl Asa and Anthony Stocks. Saint Louis Zoo, One Government Drive, St. Louis MO 63110, USA, <Pgros@ibw.com.ni> (PG and CA), Department of Anthropology, Idaho State University, Pocatello ID, USA (AS).

MAYANGNA PEOPLE ASSESS BIODIVERSITY AND ITS TRADITIONAL USE IN BOSAWAS: A QUEST FOR SUSTAINABILITY

In BOSAWAS Biosphere Reserve, Nicaragua, indigenous people may be the best stewards of rainforest conservation. This paper presents an original attempt at inventorying mammal and bird species, assessing hunting sustainability, and fostering conservation management using Participatory Action Research. Inventories were conducted across habitat types by a team of indigenous rangers assisted by one of us (PG). We combined direct observation, track records, and infra-red camera photography for mammal inventory, and based bird inventory on observations, calls, and mistnetting. Relative densities of larger mammals and birds were approximated from monthly surveys along 12 km line transects distributed under three land-use regimes: agriculture, hunting, and conservation. Indigenous women monitored wildlife meat consumption in three communities for one year, visiting 100% of households on a weekly basis. We found that BOSAWAS harbours the full assemblage of large mammal and bird species of Central American rainforests. Track densities were high compared to other studies in the region. Hunting appeared sustainable for most wildlife species. However the functionality of this system is threatened where indigenous land borders mestizo communities. Involving indigenous leaders and villagers at all stages of this project is more likely to promote long-term conservation by indigenous communities than would external laws or regulations.



14.45 - 15.00
DOVIE, DELALI K.B., Ed T.F. Witkowski and Charlie M. Shackleton. Restoration and Conservation Biology Research Group, School of Animal Plant and Environmental Sciences, University of the Witwatersrand, Wits 2050, Johannesburg, South Africa, <delali@gecko.biol.wits.ac.za> (BKDD, ETFW), Environmental Science Programme, Rhodes University, Grahamstown, 6140, South Africa (CMS).

DIRECT-USE VALUE OF BIODIVERSITY, SUSTAINABLE LIVELIHOODS AND CONSERVATION

We present account of the importance of direct-use value of biodiversity in the form of non-timber forest products (NTFPs) in a semi-arid savanna woodland biome of South Africa. The monetary value of most NTFPs is often neglected in national accounting, and macro-level policies and in main-line ethnobiological studies. In a study to examine the precise contribution of NTFPs to rural livelihoods, it was found that NTFPs contributed 19.4% equivalent to US$559 direct-use value per household per annum to household incomes in the context of other sources; crops (15.4%), informal cash income (15.6%), livestock (22.7%) and formal income (26.9%). Resources harvested included medicinal plants, wild edible herbs and fruits, insects, fuel wood, housing materials and several miscellaneous uses. Every household depended on at least one type of NTFP. There were signs of unsustainable harvesting, and for the over 43% endemic species in the savanna woodland biome of southern Africa, one cannot overrule threats of "insignificant" but potentially damaging uses. We argue that valuation of NTFPs is a key tool for conserving biodiversity outside protected areas. In conclusion, household behaviour in relation to resource use is paramount to the measure of changing attributes of biodiversity, and conservation planning.