SUSTAINABLE RESOURCE USE

ALIEN PLANTS

Invasion in Protected Areas

Management

Employment

Mpenjati Nature Reserve

Funding

Clearing operations are mostly funded by the Department of Agriculture and Environment Affairs: Invasive Alien Species Programme.

EKZNW is currently looking into other possible funding options to fund the shortfall. In order to address the current infestation in all protected areas EKZNW would require R 60 million per annum for the next ten years. Currently DAEA provides R 30 million per annum. Conservatively estimated invasive alien plants spread at a rate of 5% per annum, should clearing of the current infestation be delayed by ten years it would increase the cost by 55%.

ALIEN PLANT IMPACT

What impact are invasive alien plants having on EKZNW protected areas?

Over 9000 species of alien plants can be found within South Africa. To date, 198 of these species have been legally defined as alien invader plants. These species are non-native, non-indigenous, foreign or exotic and have the ability to spread naturally (without the direct assistance of people) in natural or semi-natural habitats. Invader plant species produce a significant change in terms of composition, structure, or ecosystem processes. From a nature conservation perspective, the mere presence of an alien invader plant species is a threat.

However, not only do alien invader plant species pose an ecological threat, but potentially have dire social and economical ramifications as well. For instance, a far-reaching ecological, as well as economic and social, implication is the depletion of South Africa’s water resource that alien invader plant species incur. In KwaZulu-Natal, alien invader plants use approximately 576 million m3 of water per annum more than the natural vegetation they have invaded and replaced.

Invasive alien plants also have a significant impact on the ecological integrity of our natural systems, the productive potential of land, the intensity of fires, flooding, erosion, the health of estuaries, water quality and quantity and the livelihoods of all those who depend on the life-support systems that these invasive alien plants undermine. KZN is no exception, with alien infestation having a major impact on the ecology throughout the province.

A number of examples are discussed below. Although these pertain primarily to Zululand, the principles thereof may in the majority of cases be similarly applied to the other regions of the province. One of the biggest threats within the Zululand region is Chromolaena odorata (Triffid Weed). It is known to reduce the grassland, savannah and forest vegetations to monotypic vegetation irrespective of the systems properties (Goodall & Zachariades, 2002). It is this biotic homogenization and the suppressing of the indigenous plant communities that results in endemic species loss and habitat destruction (MacDonald and Jarman, 1985; McKinney and Lockwood, 1999). C. odorata poses a threat to species diversity. C. odorata has invaded many of Zululand’s Protected Areas and consequently many of the research initiatives within Zululand and its surrounds have concentrated on C. odorata.

Crocodiles (Crocodylus niloticus) which occurs in several of the Zululand Protected Areas have a temperature dependent sex determination (Hutton, 1987; Leslie, 1997). In a study by Leslie and Spotila (2000) they investigated the impact of C. odorata on C. niloticus nest site selection, nesting success and resultant hatching sex ratios in the Mpate River breeding area in the Greater St Lucia Wetland Park, KwaZulu-Natal. They found that the alien plant species poses a very serious threat to a continued survival of the C. niloticus in the Lake St. Lucia ecosystem. Their data confirmed that C. odorata has a shading effect on nesting sites, and that this shade has reduced incubation temperatures. Nests in shaded sites would, therefore, be well below the pivotal temperature for C. niloticus at St Lucia and would therefore be expected to produce a female-biased sex ratio. Of the six nesting site investigated, three have been invaded by C. odorata. If C. odorata remains uncontrolled and continues to spread, a female-biased sex ratio in all nesting areas may result in the eventual extirpation of C. niloticus from Lake St Lucia ecosystems (Leslie and Spotila, 2000).

Similarly, turtles and some lizards also have temperature-dependant sex determination (Hutton, 1987; Bull and Charnov, 1989; Janzen and Puakstis, 1991; Wibbels, Bull et al., 1992; Leslie, 1997), thus their existence may also be threatened by invading alien plants species such as C. odorata. According to Samways and Taylor (2004), many of the endemic dragonflies and damselflies (Insecta: Odonata) are threatened by invasive alien trees, in particular Acacia mearnsii (Black wattle) and Acacia longifolia (Long-leaved Wattle). These trees shade out the vegetal understorey and, as a result, grasses that are perching sites for these species, and bushes that are oviposition sites, are disappearing.

In the Zululand Region, the globally threatened Pseudagrion newtoni (Harlequin Sprite) and the nationally threatened Lestinogomphus angustus (Spined Fairytail) are examples of such species that are threatened. A study on ‘Invasion biology of the alien invasive plant C. odorata in a South African savanna’ is currently being conducted in HiP. Preliminary analyses show that the aggressive invasive nature of this species can be attributed to its exceptionally high growth rate and its enormous seed production. It appears that overall herbivore densities within C. odorata infested areas are low, but it is uncertain whether this is related the presence of C. odorata or merely a characteristic of the area in which the experiment is set up. However the results do indicate that grazers are negatively affected by C. odorata, while browsers are affected positively, or it is possible that the affect may be neutral. The plants species diversity in infested areas is not affected to a great extent, but the abundance of indigenous plant species is significantly decreased by the presence of C. odorata. In areas that were cleared of C. odorata, the herbivore community has shown a shift from purely browsers to a mix of browsers and grazers. This coincides with a shift from C. odorata to grassland.

The study also showed that C. odorata invasion is lower in grassland areas than in areas supporting woodlands. Fire appears to be effective in hampering the invasion of C. odorata, especially in areas where fire has been used as a tool to reduce bush encroachment (Ms M. te Beest, pers comm.) In a study conducted in HiP on the impact of C. odorata on invertebrate density and diversity, spiders were used as biological indicators. C. odorata was shown to have a negative impact on spider diversity and density. Another aspect of this study determined if the system is able to rehabilitate itself after clearing operations. The results indicated that the treatments that were cleared 3-5 years ago have a higher spider diversity index value as compared to treatments that were cleared 1-2 years ago. This suggests rehabilitation is taking place (Ms M. Mgobozi, pers comm.)

A further study within HiP is investigating the effects of C. odorata on the habitat use of L. pictus and on small mammal diversity. L. pictus is among the most endangered species in the world, and is extinct in 25 of the 39 countries which it occupied. Because L. pictus have large home ranges, habitat loss is clearly a problem as it reduces population size thus increasing the extinction risk. In addition small mammal monitoring can be used as a method of indicating whether the functioning of an ecosystem is healthy or unhealthy and may facilitate the management of nature reserves and future development of natural areas. From the preliminary data, it appears as if L. pictus is neither avoiding nor preferring the areas invaded with C. odorata. However, anecdotal data shows that they sometimes use C. odorata to improve capture by chasing their prey into dense stands of the weed. L. pictus has also denned in areas of high C. odorata infestation. This may help protect the den from Panthera leo (Lion) and Crocuta crocuta (Spotted Hyena). However, more analysis needs to be done on the data to confirm these findings. The same study also found that areas that have been invaded for long periods have the lowest small mammal diversities (Ms L. Dumalisile, pers comm.) .

The invasion by C. odorata is clearly having a significant impact on habitat dynamics within in HiP and elsewhere, however, the long term consequences of these invasions still need to be established. Questions have also been raised on what impact C. odorata is having on flagship species, such as the endangered D. bicornis (Black Rhino). Consequently, the need for ongoing research is vitally important in furthering our knowledge and understanding of all invasive alien plant species and their associated impacts.

BLACK RHINO IN ISIMANGALISO

BLACK RHINO MANAGEMENT IN THE iSIMANGALISO WETLANDPARK

By AJ Conway
EKZNW CM iSimangaliso WetlandPark
Member IUCN AfRSG
Member SADC RMG
Chair: KZN Rhino Group

The black rhino is classified as Critically Endangered in the IUCN 1996 Red List of Threatened Animals. Yet as recently as the 1970’s, it was estimated that over 60 000 black rhino were still roaming Africa. Poaching, combined with inadequate field protection has decimated these populations throughout the continent. The target being their horns for medicinal purposes in the East and tradition daggers in Yemen. Of the four black rhino subspecies, the future of the western black rhino is especially bleak, with the species probably now extinct in Cameroon, the last known population. The south-central black rhino (Diceros bicornis minor) which we have here in KwaZulu-Natal is the most numerous, yet still has only an estimated population of 1866 in the wild worldwide, of which 1258 occur in South Africa.

Some populations have increased well under protection and others appear to have stabilized during the 1990’s. The most recent estimate of 3 726 black rhinos (all four species) in December 2006 indicates that they are showing a gradual increase.

In KwaZulu-Natal there are 460 black rhino (D. b. minor) of which 90 (ninety) occur in the iSimangaliso Wetland Park, in uMkhuze, Western Shores and Eastern Shores of Lake St Lucia

To prevent rhino disappearing forever it is necessary to protect them from poaching and manage them to maintain rapid population growth. And it is with this defining principle in mind is that drives the management initiatives in the iSimanagaliso Wetland Park in respect to black rhino and indeed other rare and endangered species such as white rhino, wild dog and oribi.

The protection of black rhino involves an elaborate security system which involves field rangers and section rangers patrolling the areas that they frequent daily and record details of all sightings of black rhino on prescribed forms which are later captured in a database at the section headquarters. The details are strictly quality controlled and the life history of as many animals as possible are tracked through personal history sheets. It is for this reason that every two years expensive ear-notching operations take place with helicopters and immobilizing drugs. The principle being that the more animals that are known in a population the greater control one has over the population estimate and performance, in measuring for example date at first calving, inter-calving intervals, calf mortalities, home ranges etc. All this data also provides valuable historical data in the event of an animal that disappears and serious manpower and effort is mobilised to try and locate the animal.

In terms of maximizing the black rhino population performance (breeding) the rhino strategy for the Park follows the guidelines and principles set by the IUCN African Rhino Specialist Group and the SADC Rhino Management Group, which prescribes a set harvesting rate for populations at or near ecological carrying capacity. In the case of uMkhuze and EasternShores the harvesting rate is set at 5% per annum. The WesternShores population has been recently established and the population will only be harvested in about 8 (eight) years time when the population of black rhino exceeds 75% of carrying capacity.

There is an exciting new development with the fencing Ozabeni, a large (50 000ha) section of the Park, which is ear-marked for a founder introduction of black rhino in 2008. This introduction will provide a vital link between EasternShores and uMkhuze, furthering the viability of black rhino in the iSimangalisoPark.

The introduction to Ozabeni will top the 100 figure of black rhino in the iSimangaliso WetlandPark and securing it the highest status possible, a KEY 1 population in terms of the IUCN African Rhino Specialist Group rankings – a great achievement worth protecting and maximizing performance for the survival of the black rhino forever!!

FISH TRAPS AT KOSI

KosiBay fishtraps: From dying out to too successful?

In the early 1980’s Kosi Bay was a rural backwater of Apartheid South Africa with almost no employment opportunities. The migrant labour system milked the area of its youth and infrastructure was rudimentary. The result was that the traditional fishtraps, which were an important part of Zulu culture, were dwindling in numbers and trapping was a dying art.

The area was recognized as having outstanding biodiversity and scenery and steps were taken, at the highest level, to enhance its conservation status. Kosi Bay was proclaimed a Nature Reserve, Ramsar wetland of international importance and included in South Africa’s first World Heritage Site. During this process, efforts were made to investigate fish trapping and establish its impacts. Research results suggested that catches were sustainable and not in direct conflict with recreational and other fishers. Traps caught a fairly small proportion of the fish migrating to the ocean to spawn and recreational anglers in the lakes and had an opportunity to catch fish before their migrations.

As a result of the findings trapping was recognized as a legitimate fishing method and, while improved management reduced illegal and unsustainable fishing methods, it reversed the decline in trap numbers. The collapse of the migrant labour system, after the end of Apartheid, resulted in large numbers of unemployed young men returning to Kosi Bay. There were still few employment opportunities but one opportunity was to build fishtraps and sell the catch. The result was a marked and sustained increase in the number of traps, with more than a doubling in numbers between 1994 and 2000. Another result was to convert a generally subsistence fishery into a mostly commercial operation.

QUESTIONS AND ANSWERS

In the Ukhahlamba (Drakensberg) area the main concern is wattle, pine, lantana and bramble. Along the Coast as with the Zululand reserves the main invasive plants already established in many areas are chromolaena and lantana. Other species such as parthenium, pereskia, madeira vine are often found in small communities inside PA’s but due to their invasiveness in other areas of the country/ world they are a real concern and are being treated as soon as they are spotted. Senna, mauritius thorn, castor oil, madagascar periwinkle, and sword fern among others also occur in PA’s.

A survey conducted by Lesley Henderson in 2006 of many of the protected areas provided EKZNW with a list of species and location of occurrence in each PA. These lists are updated and kept in a central database. Also densities in an area are updated annually to update clearing costs.

Alien species refer to any animal or plant, or any other type of organism that is introduced to a new area through the accidental or deliberate actions of humans, but which are not necessarily invasive. The important fact that needs to be highlighted is the involvement of humans in the introduction of such species either deliberately or accidentally, e.g. deliberately through introduction of an ornamental plant for sale in nurseries which has become invasive, e.g. Yellow bells (tecoma stans) or accidentally, triffid weed (chromolaena odorata) it has been suggested that it was introduced into the country during the second world war in a shipment of horse feed.

This definition excludes the natural migration of native species to new areas due to environmental changes or influences.

Invasive species produce reproductive off-spring, often in very large numbers, at a considerable distance from the parent plant, and have the potential to spread over large areas.

It has been suggested that plants that spread over 100 metres in less than 50 years warrant classification as invasive species. For plant species spreading by roots, rhizomes, stolons, or creeping stems, it is suggested that spreading more than six metres within a period of three years would constitute an invasive species. Therefore it can be said that how quickly and how far a species spreads defines its invasive status.
The following are examples of known negative impacts of invasive alien plants:

• Loss of biological diversity through permanent changes to habitats, e.g. indigenous woodlands being changed to alien plant thickets.
• Reduced water flow where fast-growing alien trees use far more water than the locally adapted native grasses and shrubs.
• Artificially high fuel loads created by combustible alien plants invading forests and forest margins, causing fires of high intensity to penetrate the forest canopy, e.g. triffid weed.
• Disruption to dispersal of indigenous seeds: birds develop a preference for feeding on alien fruits, e.g. rameron pigeons have been found to prefer bugweed (Solanum mauritianum) to black stinkwood (Ocotea bullata) fruits
• Important breeding sites being overrun by alien plants, e.g. crocodile nesting areas in Lake St Lucia.

No, only a small percentage of introduced species become naturalized or invasive. Many alien species are highly beneficial to humans, e.g. potatoes. Importantly, though, many alien species may not yet be invasive, but may well have the capacity to become invasive over time, for example when they reach habitats that are more suitable, or once conditions change to enhance their reproductive rate and/or ability to spread.

Many South African plants have been taken to other countries for their commercial and/ or ornamental value. However, once in these countries some of the species have become invasive such as the Arum lily (Zantedeschia aethiopica) and several species of Watsonias which are invasive in Australia.

It is important to be aware of what species are alien and which are invasive. There are laws that prohibit nurseries from selling certain species and laws that prohibit people from having certain plants in their garden/farm/reserve. For more information visit the following websites: Working for Water Programme, Plant Protection Research Institute, or the Global Invasive Species Programme

By visiting the websites indicated above, or by reading Lesley Henderson’s “Alien Weeds and Invasive Plants” book, which can be purchased by calling Eunice Kiwane at (012) 808 8222, her e-mail address is kiwanee@arc.agric.co.za. Another book recently published by WESSA “Invasive Alien Plants in KZN” is available through the Wildlife and Environment Society of South Africa’s Durban office, 100 Brand Road. This book lists the 40 most invasive alien plants in KZN and is well illustrated and provides recommended treatment methods, this book is available at R 35.

In a garden treating alien plants can be as easy as pulling them out, or by using a broad leaved herbicide sprayed as per label recommendations. However it needs to be kept in mind that these plants are aggressive growers and one needs to go back to these plants regularly and see whether they have died, if not one needs to repeat treatment.

In larger areas a clearing plan is essential. Best practices include keeping clean areas clean, starting from lowest density areas first (as areas highly infested cannot get any denser), clear vectors of spread, e.g. if invasion is along the road entering your property then clear along the road verges, also be aware of new invasive plants entering your property which have the potential to spread. Ensure that you follow up regularly, e.g. at least before the plant sets seed annually.

Clearing methods for specific plant species are indicated in “ Invasive Plants of KZN” which can be purchased through the Wildlife and Environment Society’s Durban office, 100 Brand Road, at R 35. This book lists the 40 most invasive alien plants in KZN and is well illustrated and provides recommended treatment methods.

RARE, THREATENED AND ENDEMIC SPECIES

The iSimangaliso Park Rare, Threatened and Endemic Species project.

The iSimangaliso WetlandPark Threatened Species Project is an Ezemvelo KwaZulu-Natal Wildlife special project, supported by the iSimangaliso Wetland Park Authority and Wildlands Conservation Trust. Initiated in 2003, the overall objective was to promote the conservation of the rare, threatened and endemic species of the Park. It produces information on their presence, distribution and management, focussing on the less charismatic groups such as smaller mammals, reptiles, beetles, orchids and cycads. This is achieved through an analysis of existing information as well as field surveys with the assistance of international volunteers.

Due to the size of the Park it was decided to conduct baseline surveys targeting 14 sample survey sites representative of the broad habitat diversity of the Park. In 2006, an Atlas approach was piloted in uMkhuze. The main advantage of this type of approach is equal effort during the surveys, which then provides information on the relative abundance of species, in addition to data on presence and spatial distribution.

As a result of the cryptic nature and nocturnal habits of many of the priority species, live trapping and active searches during the day and night are conducted. Trap stations consist of pitfall traps combined with plastic drift fences, funnel and rodent traps. Active searches are conducted once all trap stations are in position, searching under logs, rocks and other suitable habitats and refugia, as well as in the top layer of the soil for ground dwelling fauna. Road cruises, bat and amphibian surveys are conducted at night.

The majority of specimens are identified in the field then released but a small proportion require further investigation by a taxonomic expert for identification and they are deposited at a museum.

New records for the province of KwaZulu-Natal include the rufous hairy bat, desert pigmy mouse, Thomas’ pygmy mouse, bicoloured musk shrew and two-striped shovel-snout snake. Confirmed new records for the iSimangaliso WetlandPark include the least dwarf shrew, tiny musk shrew, Namakwa rock mouse, bald ibis, floodplain water snake, striped harlequin snake, delalande’s beaked blind snake, holub’s sandveld lizard, six fruit chafer and four epiphytic orchid species. One of the main reasons the Park was proclaimed a World Heritage Site was its very high biodiversity. This project removed 14 species erroneously included in the Park species lists but has added over 150 new species.

During the past two years, the project has facilitated an MSc research study on the Gaboon Adder (Bitis gabonica), one of the flagship snake species of the Park. The main foci of the research were radio telemetry, movement patterns, habitat use and thermal strategies. In conjunction with distribution information and molecular work, ecological data from this study will provide practical management recommendations and an accurate description of the conservation status of the Gaboon Adder in South Africa .

Part of the mission of the iSimangaliso WetlandPark is managing and protecting the ecosystems and biodiversity according to the stringent standards of the South African government and UNESCO’s World Heritage Commission. During the past five years the Threatened Species Project has played a unique role in working towards that goal by providing management with improved tools to identify and care for the most vital components of the Park biodiversity.

SUCCESS ACHIEVED

Success Achieved

The Hluhluwe –iMfolozi Park (HiP) is the oldest proclaimed game park in South Africa, and has been instrumental in saving the white rhino (Ceratotherium simum) from extinction. Over the years HiP has become invaded with invasive alien plants. By 2003 70% of the park’s over 90 000 hectares was seriously infested, posing the greatest threat to the biodiversity of the park. Control programmes have been ongoing since the first invasions, yet the funding and programmes to curb the spread have always been inadequate to stop invasion. In 2003 a large scale clearing operation was established, with poverty relief funds aimed at using labour intensive methods. Dangerous game, difficult terrain, the size of the operation, and prioritization of clearing made this programme a difficult undertaking.

Five years later HiP has become a success story. This has been due to adequate funding which has been sufficient to allow the rate of control to exceed the rate of spread, a clearly defined prioritization schedule, regular mapping surveys, a dedicated invasive alien management team, an emerging weeds team, ongoing safety and clearing standards training for the more than 500 workers in-field at any time, and support from all levels of management. Currently the infestation reduction is estimated at over 90% and close to 50% of the park is under maintenance, while the remaining is at various stages of treatment, e.g. first follow- up, fourth follow –up, etc. Only 1200 hectares remain to be treated. Efforts to control the spread are ongoing. Although the spread of invasive alien plants had been curbed inside the park, many areas bordering on the park are highly infested; the challenge is to get these areas cleaned to prevent re-infestation. This has been done through engaging with the local district municipalities to create a district clearing plan and thereby lobby funding, which is an ongoing initiative. A recent study conducted by Mandisa Ncgobo indicated that the biodiversity of the sites in her study actually rehabilitated quite soon after clearing. This is phenomenal and indicates that the investment of over R 60 million since 2000 was well worth spent.

Through long term funding first from Working for Water and then the Department of Agriculture and Environment Affairs some of the Protected Areas have reached a “maintenance phase” (where densities are less than 2%) some of these reserves are Tembe, Umgeni Vlei, Vryheid Hill, currently an average of 10 000 hectares are moving to maintenance phase annually.

UMKHANYAKUDE DISTRICT MUNICIPALITY

DISRICT MUNICIPALITIES

The structure of the South African government system is designed so that district and local municipalities are the implementation arms of government. In respect of this and taking into consideration that ultimately, KZN Wildlife is accountable to government for the resources allocated to manage the biodiversity of the province, it is important that the projects undertaken by the organization take cognisance of the district municipality's priorities as well as their own. If in one region, there is a district municipality that has a problem with a scarcity of water, it makes much more sense for KZN Wildlife to have district projects that will concentrate on the removal of alien plants which use so much water. Similarly, if there is a KZN Wildlife camp that is not generating as much revenue as expected due to inaccessibility, it makes sense for the district municipality to prioritize road construction or road maintenance to the camp in question, instead of a totally unrelated project. Umkhanyakude District Municipality is located in the North east corner of KwaZulu-Natal, South Africa. The regions claim to fame is the iSimangaliso Wetland Park (formerly Greater St Lucia Wetland Park) World Heritage Site, as well as a number of large protected areas namely the Hluhluwe – iMfolozi Park, Ndumo Game Reserve and the Tembe Elephant Park.

This district is rich in both its natural wildlife and terrestrial ecosystems but also boasts two marine protected areas and rich diving attractions.

KZN Wildlife is responsible for conservation management within these protected areas and also plays an active role within the district. A number of district conservation officers offer expert advice to private and community landowners in either game farm management or conservation issues. A community conservation team drives the conservation awareness and community partnerships focus for the organisation. They actively interact with local communities and municipalities.

KZN Wildlife is also responsible for a number of large scale project initiatives. These include massive alien plant clearing programmes, Transfrontier Conservation Area initiatives and DEAT funded Coast Care and development projects. KZN Wildlife’s Community Levy programme has made constructive improvements to infrastructure within this District.