|
[Plant systematics]
[Ethnobotany] [Sabonet]
[Ecology and Conservation] [Libraries]
[NBI Websites]
ECOLOGY AND CONSERVATION
[Climate Change] [Conservation
Farming] [Cycad Conservation] [Protea
Atlas Project] [Seed Research]
Scientific staff in the Ecology and Conservation Directorate, based
at the Kirstenbosch Research Centre, were active with ongoing research
projects that have firmly positioned the NBI as a key player in
biodiversity science and conservation in Africa. Scientists continued
to provide national leadership on policy research and advice in
the area of plant diversity and sustainable use.
CLIMATE
CHANGE
In 2001 funding was approved for a new two-year collaborative project
between the NBI (South Africa) and the CNRS* (France) under the
auspices of the Climate Change programme. The project Functional
changes in vegetation of the Cape region (Floristic Kingdom) in
response to global change is centred on the study of plant functional
types along gradients between karoo and fynbos vegetation. NBI scientists
participated in the first science planning meeting in Montpellier,
France, in July to set the agenda for the first year's work on this
project which will add to the understanding of plant form and function
in two biodiversity hotspots.
Other climate change research projects currently under way include
an examination of the effects of global climate change on savanna
ecosystems, the effects of elevated atmospheric CO2 on grassland
ecosystems and corridor design for biodiversity conservation in
the face of climate change.
The results and potential implications of the climate change research
under way at the NBI were also presented at a workshop on Climate
change and forests in Tanzania, as well as at international workshops
in France, Kenya, the United Kingdom and the United States. One
of the scientists from the Climate Change Programme was invited
as scientific advisor to a DEA&T presentation on Climate change
impacts on South Africa, delivered to the South African government
cabinet.
A colourful popular booklet sponsored by WWF-SA summarizing the
results of earlier climate change research, The heat is on - impacts
of climate change on plant diversity in South Africa, was released
to the media in September and generated a number of newspaper, radio
and television reports, including international wire news stories
in the United Kingdom and United States.
|
CLIMATE CHANGE RESEARCH RESULTS
- Bioclimatic modelling has revealed the potential extinction
risk facing indigenous species of the Fynbos and Succulent
Karoo Biomes. In the Fynbos Biome, the Protea Atlas Database
enabled the use of this group to estimate the extent of
climate change impacts on natural plant species. Up to 30%
of indigenous Proteaceae face extinction if they are unable
to shift their geographic ranges completely to keep pace
with climate change. Up to 60% of Proteaceae species could
lose more than 90% of their current geographic range. Poorly
dispersed species are particularly vulnerable. Rare species
with small geographic ranges are generally more at risk
of range dislocation (complete range shift or range extinction)
than common species with broader ranges.
- Fieldwork on seed dispersal has found that occasional
extraordinary wind events (probably whirlwinds) are able
to provide significant seed dispersal events, suggesting
that wind-dispersed species may be more able to track climate
change than ant- or rodent-dispersed species in the Western
Cape. In the arid Succulent Karoo, a combined modelling
and fieldwork study on Aloe dichotoma (kokerboom or quiver
tree) has revealed a remarkable agreement between the modelled
predictions of expected mortalities and population decline,
and observed population decline. This suggests that the
modelling techniques used are robust, and that the early
signs of climate change may already be visible in our natural
vegetation.
- Dynamic modelling has revealed the close dependence of
tree/grass balance in savanna systems to atmospheric CO2
levels. Rising CO2 strongly promotes the success of trees
growing competitively with grasses, and this effect is mediated
by fire frequency. This work shows that previous interpretations
of grassland expansions in southern Africa during glacial
conditions that have been understood as signs of aridity
should be re-evaluated. It seems that rising CO2 has been
under-appreciated as a factor behind the national problem
of bush encroachment. This phenomenon could therefore be
important in calculating the cost of atmospheric CO2 increase
to this country and in assessing the ability of natural
savanna and woodland ecosystems to sequester carbon.
- Results of the project on elevated atmospheric CO2 on
productivity and water use of South African C4-dominated
grassland ecosystems have indicated the potential for improved
ecosystem productivity and water use efficiency under elevated
CO2 and present rainfall scenarios. Ecosystem productivity
may be limited by the availability of other resources such
as nutrients. A shift in community structure is also possible
and is most likely influenced by availability of other ecosystem
resources apart from CO2.
- An understanding of physiological and structural adaptations
in diverse growth forms to environmental stress conditions
is important for predicting the possible impacts of climate
change on these growth forms. Structural analysis of the
ericoid leaf form, a dominant structural type in fynbos
vegetation (and an important component of biodiversity),
has revealed that this form is not sclerophyllous, and therefore
that its structure and presumed function requires a full
reappraisal. Stomatal function appears not to be determined
by water-saving considerations, but rather that stomata
are held in grooves on the abaxial surface of the inrolled
leaf in order to maintain stomatal opening under atmospherically
dry conditions. This strategy is likely to maximize carbon
uptake during common windy and dry conditions.
- A new project focuses mainly on the ecophysiological responses
of the economically significant indigenous savanna plants
to climate change scenarios projected over geological time
scales. The preliminary findings suggest that three tree
species, namely Acacia karroo, A. nilotica and Dichrostachys
cinerea, respond differently to CO2 treatment. It appears
that A. karroo and A. nilotica might flourish under conditions
of higher CO2 compared to D. cinerea, since the former two
species appear to have invested much carbon in above-ground
plant material as opposed to the latter. However, the question
of below-ground carbon investment is very important and
needs still to be investigated.
|
CONSERVATION
FARMING
The Conservation Farming Project received very positive
feedback from the project funders, the Global Environment Facility,
who visited the project during the year as part of their global
evaluation of medium-sized projects.
To date, workshops have been held in all four study sites included
in the Conservation Farming Project. The workshops involve researchers,
farmers, and labourers from a range of farms in each district. A
key factor emerging from all the workshops is that farmers lack
information and support services.
Twenty-one contract staff and consultants have been appointed to
assist with the Conservation Farming Project. Most of these appointments
are researchers and this has provided a boost for ecological research
in South Africa. Ten student projects are currently being supported
as part of the project, including five Ph.D. projects.
The Conservation Farming Project website (http://www.nbi.ac.za/consfarm/cfindex.htm)
was substantially updated to enable stakeholders to download relevant
information. The website now contains fact sheets, a reference database
and information on sites.
As part of an ongoing sponsorship agreement, Mazda Wildlife Fund
supplied the Conservation Farming project with a new vehicle.
|
CONSERVATION FARMING RESEARCH RESULTS
- A project on the importance of porcupines as ecosystem
engineers in the Nieuwoudtville area is nearly complete.
The data showed that porcupines turn over large volumes
of soil and selectively remove certain bulb species. Preliminary
analysis suggests that this activity maintains bulb diversity,
increases rainfall infiltration (up to 10 times faster in
areas with porcupine diggings than in areas without porcupines),
and influences the storage of soil carbon (areas with high
bulb numbers associated with porcupine activity contained
much higher levels of soil carbon).
- Studies of seed dispersal of Brunsvigia bosmaniae
were used to provide detailed data on the effects of land
use on dispersal and establishment of different groups of
plants. The results showed that dispersal was interrupted
by farm structures such as fences and also occurred only
in specific 'corridors'. This means that once plants are
eliminated from a landscape, they cannot always re-establish
from seeds. Moreover, establishment depended on a combination
of soil type and rainfall. Under low rainfall, plants established
only on dolerite soils, but they would establish on other
soils under higher rainfall.
- Data on soil carbon together with above- and below-ground
biomass have now been collected at three of the four study
sites. This means that the amount of carbon stored in the
soil and in plant biomass per hectare can be calculated,
giving an idea of how carbon sequestration changes with
land use.
- Experiments on the effects of fire, as a land management
option, on the presence and flowering of geophytes in the
Nieuwoudtville area were also undertaken. The study compared
unburnt plots with plots that were burnt or brush-cut. Findings
showed that flowering increased in burnt and cut plots but
that there were no species that flowered only after fire.
Frequently burnt plots were found to have substantially
fewer species.
|
CYCAD CONSERVATION
The NBI has been instrumental in completing a status survey and
action plan for the world's cycads, which was submitted to the IUCN
for final publication in 2002. The Cycad Action Plan clearly identifies
priority species and areas for conservation and therefore makes
it easier to access funds for specific projects.
The IUCN Cycad Specialist Group has been reconstituted for the
next three-year term specifically to carry out the actions outlined
in the Cycad Action Plan. The members represent eight countries
(Australia, China, Kenya, Mexico, South Africa, Thailand, USA and
Vietnam). The key areas that the group will focus on are Red Lists,
collections in botanic gardens, habitat conservation, trade, liaison
with cycad enthusiasts, taxonomic information, sustainable utilization
and community nurseries in developing countries, and fund-raising.
|
RESEARCH RESULTS
- The fieldwork for a National Geographic Society-funded
project on cycad pollination was completed in December 2001
and generated several significant results. Thrips have been
discounted as effective pollinators in many plant groups
because of small pollen loads. Cones visited only by thrips
had the same number of pollen grains per ovule as beetle-pollinated
cones. Cycads pollinated by thrips were furthermore found
to have diurnal heating patterns and volatile attractants
that were different from those of cycads pollinated by weevils.
- Research into how cycads with different life histories
respond to harvesting is being used to develop government
policy on cycad trade. An analysis of 10 years population
data for two cycads showed that seed harvesting had a negligible
effect on cycad populations, even when adult life spans
varied from 50 years to > 300 years.
|
PROTEA
ATLAS PROJECT
The Protea Atlas Project entered a new phase with the start of
an externally funded collaborative project aimed at statistical
analysis of the data collected by the Protea Atlas Project over
the past 10 years. To this end, the project leader and co-workers
attended workshops on Bayesian statistics and modelling in Santa
Barbara, USA. Bayesian modelling is being employed to predict the
distribution and biodiversity of proteas on environmental and spatial
variables.
Data gathered by the Protea Atlas Project is being put to use by
the Cape Action Plan for People and the Environment in planning
conservation areas, by the NBI's Climatic Research group for mapping
Global Climate Change and also to help map the vegetation types
within the Fynbos Biome.
A new and very unusual species of Leucadendron was discovered by
the Protea Atlas Project, the eighth new species to be discovered
since the Project's inception.
SEED
RESEARCH
There are a large number of rare and threatened plant species in
different parts of the world and seed conservation research aims
at establishing and perfecting the techniques required for long-term
storage of seed as a means of conserving their genetic potential.
To this end, an NBI scientist attended the Kew International Workshop
on Seed Conservation: Turning Science into Practice held in the
United Kingdom in July 2001 where opportunities for possible research
collaboration between the Kew Millennium Seed Bank and the NBI were
discussed.
LIBRARIES
MARY GUNN LIBRARY
The Mary Gunn Library, housed at the National Herbarium, continued
to provide a valuable service to the scientific staff of South African
research institutions, as well as support to institutions in the
SABONET network.
The Library enjoyed a busy year, with almost 2 000 books and photocopies
of articles issued and over 5 400 telephonic and e-mail enquiries
fielded. Over 2 650 copies of the contents pages of new journals
were circulated to internal users and SABONET participants and 800
books and photocopies of articles were requested through national
and international interlibrary loans.
A presentation on the management and administration of a library
was given to participants in the SABONET Botanical Gardens Management
Course. The Mary Gunn Library was marketed through an article in
SABONET News as well as through the NBI website.
HARRY MOLTENO LIBRARY
The Harry Molteno Library, housed in the Kirstenbosch Research
Centre, experienced a successful year, with an increase in all the
main areas of activity. Over 1 300 enquiries were processed and
almost 1 100 books issued. The Library hosted a meeting of members
of the Special Libraries Interest Group at which the librarian spoke
on Developing and managing a corporate website. The Wednesday Club
visited the Library to view its rare book collection.
The increasing cost of journal subscriptions led to several titles
being cancelled at the end of 2001. This was before the drastic
devaluation of the SA rand at the end of 2001, which has very serious
implications for the library holdings unless additional funding
can be sourced, as most of the acquisitions are published outside
South Africa.
Training sessions on how to search the SABINET on-line databases
were offered free of charge by SABINET to NBI research staff.
NBI WEBSITES
The websites designed and maintained by the librarian of the Harry
Molteno Library enjoyed phenomenal growth during the year. Hits
to the www.nbi.ac.za site have almost doubled, while the use of
www.plantzafrica.com site has increased more than threefold. In
March 2002, both sites passed the threshold of an average of 5 000
hits per day.
Several additions were made to the www.nbi.ac.za site during this
period, including an expanded section on the Lowveld NBG, pages
on the Conservation Farming Project, Leslie Hill Laboratory and
the NBI-Ball Agreement. The site was constantly updated to promote
events in the Gardens, with pages developed for concert programmes,
art and sculpture exhibitions and plant fairs.
The www.plantzafrica.com site grew regularly as two Plants of the
Week contributed by staff at Kirstenbosch and the Witwatersrand
NBG respectively were added every week. Other additions to the site
were information on listed invasive plant species, descriptions
of the trees of the year, and many articles taken from past issues
of Veld & Flora. The number of hits on this site is growing
steadily as people discover its value as a source of information
on indigenous plants.
|
