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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 Conservation and Plants

Wednesday 17th July, 15.30 - 17.30, Eliot Lecture Theatre 2

Chair: Kay Havens




(BLOCK CAPITALS indicate the presenting author)


15.30 - 15.45
GRIFFITHS, MEGAN E. and Colin M. Orians. Department of Biology, Tufts University, Medford, Massachusetts 02155, USA, <mgriffit@tufts.edu>.

THE ROLE OF SALT SPRAY IN MAINTAINING NEW ENGLAND COASTAL HEATHLAND PLANT COMMUNITIES

Coastal sandplain heathlands are disturbance-dependent plant communities with limited distribution in the northeastern United States. Previous research has shown that anthropogenic fire is important for heathland persistence because it inhibits the growth of trees. We hypothesize that salt spray also plays a critical ecological role in these rare dwarf shrublands. Field surveys were conducted on Martha's Vineyard, Massachusetts, with the following goals: (1) to determine the spatial distribution of salt spray in heathlands and (2) to measure changes in plant morphology, physiology, and community composition across a salt spray gradient. We found that as salt spray accumulation rate decreased, plant height increased, leaf necrosis decreased, plant water stress decreased, and the number trees in the community increased. Additional manipulative greenhouse studies were performed to identify differences in species' responses to salt spray. Tree species showed a greater degree of growth inhibition, leaf necrosis, and water stress at high salt spray levels than native heathland species. Based on our experimental results, we propose that the effects of salt spray on plant growth provide a mechanism by which this abiotic factor maintains both the characteristic low stature and composition of heathland plant communities.

15.45 - 16.00
SCHLÜTER, EVEROSE N. and J. Michael Reed, Tufts University, Department of Biology, Medford, MA 02155, USA, <eschlu01@tufts.edu>.

THE ROLE OF MATURE-FOREST STRUCTURE IN THE DISTRIBUTION AND PERSISTENCE OF MOSS COMMUNITIES

The persistence of species dependent upon structure found predominantly in mature forest may be jeopardised by forestry practices. Currently, we are studying the potential impacts of forestry practices on moss distributions in Maine. We have identified a strong candidate for a mature forest structure specialist species in Neckera pennata, an epiphytic moss species. In this study we determined N. pennata’s distribution, including overstory habitat types, substrate types (tree species), and some potential mechanisms to explain these distributions. We sampled 1765 trees of 12 species within the virgin and industrial forests and found that N. pennata was present on only 5 tree species (mostly deciduous), and was primarily on sugar maple, Acer saccharum. The frequency of occurrence was greater in the virgin (16 %) forest than in the industrial forest (9%). In both the virgin and the industrial forests, N. pennata was found more frequently on larger trees (DBH > 40 cm).



16.00 - 16.15
Kelly, Dave, Alastair W. Robertson, JENNY J. LADLEY, Ben Montgomery and Victoria Burgess. Department of Plant and Microbial Sciences, University of Canterbury, Private Bag 4800 Christchurch, New Zealand. <j.ladley@botn.canterbury.ac.nz> (DK, JJL, VB), Ecology Group, Institute of Natural Resources, Massey University, Private Bag 11222, Palmerston North, New Zealand (AWR), Department of Biology, University of Michigan, Ann Arbor, MI 48109-1048, USA (BM)

WHY IS PERAXILLA TETRAPETALA POLLINATION BETTER ON THE EDGES OF FOREST FRAGMANTS?

Populations of the endemic New Zealand mistletoe, Peraxilla tetrapetala (Loranthaceae), are declining because of forest clearance, introduced herbivores, and reduced pollination and dispersal service from native birds. However, forest fragmentation can provide some benefits to existing mistletoe populations. We showed previously that plants growing on edges of forest fragments have higher fruit set rates than those in the interior. Here we report that this "edge effect" is caused by increased visitation rates by pollinators to plants on edges. Overall native bird (three species) visitation to flowers on edge plants was twice as high as on interior plants (P = 0.040), as was native bee (two species) visitation (P = 0.009). This increase in mistletoe pollination and fruit set on forest edges may help offset the negative effects of further forest loss, herbivory, and declining numbers of its pollinators and dispersers.



16.15 - 16.30
SUZÁN-AZPIRI HUMBERTO and Vinicio Sosa Fernández, Escuela de Biología, Universidad Autónoma de Querétaro. Cerro de las Campanas s/n, C.P. 76010, Querétaro, Qro. México, <hsuzan@sunserver.uaq.mx> (HS), Instituto de Ecología, Km 2.5 Antigua Carretera a Coatepec, Xalapa, 91000, Veracruz, México (VS).

SURVIVAL AND GROWTH OF COLUMNAR CACTI SEEDLINGS UNDER TWO OVER-HARVESTED NURSE SPECIES IN SONORA, MEXICO

Recruitment and survival of cacti in North American Deserts occurs extensively under the canopy of perennial plants (nurse plants). In the Sonoran Desert, columnar cacti and their nurse plants are extremely important for the maintenance of the ecosystem dynamics. However, important nurse species (legume trees) have been extensively over-harvested. In Bahia Kino, Sonora, México, we conducted a field experiment from 1992 to the present of the performance (survival and growth) of cardon cacti, Pachicereus pringleii, seedlings, planted under two nurse species: ironwood, Olneya tesota; and mesquite, Prosopis velutina. Ten seedlings each were planted in 24 chicken wire boxes, under six randomly selected trees per nurse species. A multivariate repeated measures analysis indicated that seedlings under mesquite have significant higher survival differences than those under ironwood (P=0.0015). Greater height increases were detected under mesquite trees (P=0.024), but significant differences between boxes within trees were detected (P=0.0008). Soil surface temperatures and photosynthetic active radiation levels differed during summer afternoon measurements (P<0.0001 respectively) that explained partially the growth and survival differences. Previous experiments comparing physical microenvironmental conditions and seedling performance in open microhabitats with those beneath nurse trees supports our conclusion of the importance of nurse plants for the conservation of columnar cacti.



16.30 - 16.45
HENRIQUEZ, CAROLINA A., Carlos Valdivia, Ramiro Bustamante and Javier A. Simonetti. Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, <chenriqu@ciencias.uchile.cl>.

LAPAGERIA ROSEA, A NATIVE CHILEAN VINE TRYING TO SURVIVE IN FRAGMENTED FORESTS

Habitat fragmentation is one of the mayor threats to native forest in central Chile, leaving many small fragments of forest surrounded by a matrix of exotics pine plantations. Lapageria rosea (Philesiaceae) survives in these fragments, but achieves lower population size and densities than in continuous forests. We studied the factors behind such a population decline, focusing on reproductive success. We compared pollination rate, fruit and seed production, and seed germination among L. rosea in forest fragments and continuous forests. Pollination rates and the proportion of individuals producing fruits were lower in forest fragments. In addition, the total number of seeds produced per individual was also lower. However, seed germination was higher in fragmented populations. Therefore, habitat fragmentation has a negative effect in the abundance of Lapageria rosea through depressing its reproductive success. Specifically, the number of seeds produced is depressed more than seed quality.



16.45 - 17.00
DE JOODE, DANIEL R. and Lisa M. Curran. Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan 48109 USA, <danield@umich.edu> (DRD), Yale School of Forestry and Environmental Studies, New Haven, Connecticut 06511 USA (LMC).

META-ANALYSIS INDICATES REDUCED PLANT SPECIES RICHNESS IN TEMPERATE FORESTS AFTER LOGGING

The majority of plant species in temperate forests are understory herbs and shrubs. The effect of logging on understory plant diversity is widely debated because of conflicting patterns of richness in logged forests. The controversy centres on whether herbaceous understory species persist and recover following logging. Over 100 published empirical studies of the effects of logging in temperate forests worldwide were compiled. From that collection, it was possible to combine data from 22 studies in a meta-analysis. We calculated the log ratio of species richness in logged forests contrasted with unlogged controls in each study to determine the effect of logging. Understory richness increased after selective logging, but clear-cutting had no net effect on richness of the total species pool. However, shade-tolerant forest resident species richness declined after logging. Among species categorised by leaf phenology, richness of both vernal and summer herbs decreased in logged forests. Silvicultural site preparation increased total species richness but slightly decreased resident richness. Although individual studies vary, the increased power and sample size possible with meta-analysis suggest that intensive logging reduces understory plant species richness in temperate forests. Future research is required to identify specific sensitive species and test potential mechanisms of decline.



17.00 - 17.15
CHEN, XIAO-YONG. Department of Environmental Sciences, East China Normal University, Shanghai 200062, P. R. China, <xychens@public4.sta.net.cn>.

WILD METASEQUOIA POPULATIONS ARE DISAPPEARING

Metasequoia glyptostroboides, a relict tree species native to Central China, was listed as an endangered species in the red book of China. This species is also one of the most successfully recovered species in the world and has been widely introduced into more than 60 countries. A survey conducted recently, however, indicated that wild M. glyptostroboides populations will disappear in the foreseeable future. There are two main causes leading to the disappearance of the wild populations. Firstly, proper habitats had been lost. M. glyptostroboides is a pioneer species, and naturally regenerates by seeds dispersed to the newly formed floodplains. Such habitats, however, had been changed to farmlands due to the dense population. Regeneration of those wild populations is very difficult and hardly any seedlings were found. Populations are mainly consisted by large trees usually diameter at breast high > 50cm. Secondly, transplants of other species, such as Cryptomeria fortunei and bamboos, and growing medical herbs under the extant wild populations may accelerate the disappearance. However, some villagers also planted M. glyptostroboides seedlings in several populations but this might significantly change population genetic composition and differ from the naturally generated populations. Suggestions are proposed to slow down the disappearance.



17.15 - 17.30
NIESTEN, EDUARD, Jared Hardner, Peter Frumhoff, and Michelle Manion. Hardner & Gullison Associates, LLC, P.O. Box 1580, Palo Alto, CA 94302-1580, USA, <eddy@hg-llc.com> (EN, JH) and Union of Concerned Scientists, 2 Brattle Square, Cambridge, MA 02238-9105, USA (PF, MM).

DESIGNING A CARBON MARKET THAT PROTECTS FORESTS IN DEVELOPING COUNTRIES

The Kyoto Protocol enshrines market mechanisms as an innovative and cost-effective means to control atmospheric concentrations of greenhouse gases. However, as do markets for many other goods and services, a carbon market may generate negative environmental externalities. Possible interpretations and application of Kyoto provisions under COP6bis and COP7 raise the concern that rules governing forestry with respect to carbon markets may increase pressure on native tropical forests and their biodiversity. By examining the economic incentives created by these decisions, we assess whether the Kyoto Protocol will encourage destruction of native tropical forests by explicitly excluding conservation of standing forests from the Clean Development Mechanism and restricting allowable forestry measures to afforestation and reforestation. We further assess how carbon crediting for forest management in Annex I (industrialised) regions under Article 3.4 creates a dynamic that displaces timber harvests from Annex I countries to developing nations in the tropics. Given the nature of timber extraction in the tropics, additional harvest pressure would certainly exacerbate biodiversity loss. Further development of carbon markets must reward rather than penalise conservation of natural forests in developing countries and, ultimately, this may only be accomplished when developing countries are fully integrated into a global cap-and-trade system.