Conservation Biology

Tuesday, March 06, 2007


Most changes in the environment affect almost everything on the earth surface. These disruptions on the earth surface are dangerous and lead to the degradation of the planet even though change occurs natural – weather, climate, tectonic movement, etc. we are just speeding up the process. One of the issues which need to be looked at is deforestation. Deforestation has environmental consequences that most people are not aware of – such as global warming. Deforestation is when an area which was forested changes to be non-forested (1). This is caused by many factors, for example urban development. The removal of trees leads to the degradation of the environment with reduced biodiversity (1).

Deforestation alters with the rate or extent of deforestation changes the carbon cycle, hydrological cycle and the amount of soil nutrition (2). Trees reduce the impacts of rain drops on the soil so if the trees are removed the vegetation is altered with because some plants depend on these trees so that they can grow. Removal of trees alters the amount of water that penetrates the soil and groundwater. This leads to increased surface runoff and decreased infiltration and percolation. Evaporation and evapo-transpiration which are the processes which takes place from the trees and plants will be reduced due to deforestation. These will lead to reduced evaporation these mean that the energy from the sun is able to warm the earth surface, which will lead to rise in temperatures. The essential nutrients such as nitrogen will be washed out of the soil by run-off and these lead to soil erosion. The soil will end up being infertile and acidic (3)

In rural areas deforestation is caused by people because of the need for fire wood. The wood is used for fire for cooking, even though some of them have electricity. In this way they save electricity since they use it for lights only and use wood for cooking and boiling water. Fire releases carbon dioxide which is the dominant green house gas which contributes to global warming. Thus destruction of trees leads to the decreased consumption of carbon dioxide by plants which results in the increase of temperature. Trees increase the quality of air by taking in carbon dioxide and it also traps other particles such as methane which are released by factories (2). Removal of trees lead to the “albedo effect which reflects more heat and light back into the atmosphere than would be the case if the dun shone on green trees” (4)

I was busy capturing data for Natural Resource and Environment at CSIR the questionnaires was taking about the type of energy preferred by people at Zimbabwe. Most people preferred wood because it was free unlike the other energy source such as electricity and generator. Some of the people complained about deforestation because almost each an every person is starting to use wood so that they can reduce the cost.

Some people think that deforestation is caused by poverty, but it is not only poverty that causes deforestation even urban development (5). When a town or city is built, the area has to be cleared of vegetation. Ecological functions can be assigned economic values, and development is not always good from an economic point of view. As a result of deforestation the temperatures are increasing dramatically. Places like Polokwane might be faced with drought in the mere future, if the condition does not change.

Deforestation differs from country to country. In Ethiopia deforestation is caused by people. People clear the forest for their personal needs such as fuel, harvesting their own crops, building of houses, e.t.c. Ethiopia is the second largest populated country in Africa and there is also famine. The population of Ethiopia increases by the day and people needs a place to stay so most of the trees have to cut so that people have a land. In the early twentieth century about 42 hectares of Ethiopia was covered by trees but now it has less than 14.2 percent of trees remaining (1). In Nigeria the cause of deforestation are logging, subsistence agriculture and fire wood. Nigeria has lost more than half of its forest in the past five years and is considered the world’s highest deforested country (1).

How can we prevent/control deforestation, especially in less developed countries? We should start implementing some efforts (or “measures”) to slow deforestation or stop cutting wood. We should also start replanting trees just like Wangari Muta Maathai who was awarded a Nobel Peace Prize for “her contribution to sustainable development democracy peace” (6) in 2004. She planted over 30 million trees across Kenya to prevent soil erosion. In South Africa and other countries such as Australia, Canada and others have a day where they plant trees. The day in which trees are planted world wide is called Arbor Day (7).

We should also start using wood cautiously, remembering the after effects of cutting all the plants. People should also be educated about how the importance of plants. We should start taking care of trees and plants, if we do not do so we are going to pay the price.


[1]. Wikipedia contributors. Deforestation [Internet]. Wikipedia, The Free Encyclopedia; 2007 Mar 1, 10:30 UTC [cited 2007 Mar 1]. Available from:

[2]. Beamon, C and Cargill, C.J. Deforestation and Desertification. [Internet]. Available from:

[3]. Jocelyn Stock Andy Rochen. The Choice: Doomsday or Arbor Day. [Internet]. Available from:

[4]. Barnekow Lilleso, J. P, Dhakal, P, Kjaer, E. D, Nathan, I and Shrestha, R. (2000). Conservation of trees through use by local people and decentralized seed distribution supported by a tree seed programme. [Internet]. Available from:

[5]. Collins, J. Deforestation. [Internet]. Last Updated: 2001 Feb 01. Available from:
[6]. Wikipedia contributors. Wangari Maathai [Internet]. Wikipedia, The Free Encyclopedia; 2007 Mar 6, 06:06 UTC [cited 2007 Mar 6]. Available from:

[7]. Wikipedia contributors. Arbor Day [Internet]. Wikipedia, The Free Encyclopedia; 2007 Feb 26, 21:01 UTC [cited 2007 Mar 6]. Available from:

Lethabo Mosomane
Tel: 27 12 841 2133
Fax: 27 12 842 3676

The Modjadji cycad Encephalartos transvenosus

Cycads are an ancient group of seed plants meaning that they are spermatophytes. During the Jurassic period, cycads were common in many parts of the world e.g Japan. Today cycads are very few in tropical and subtropical regions and in southern and northern hemisphere. While large numbers of cycads are found on the continents of Australia, South America, and South Africa. Many cycads live 200 million years ago before the dinosaurs roamed the earth. Cycads grew well during eons period that is 150 million years ago (1). The arrival of dinosaurs caused a decrease in the number of cycads (1) because they fed on cycads. During that time, herbivores were dominant.

Today cycads are few and there is a need for Department of Agriculture Conservation and Environment to conserve few cycads that are available as they do not grow anywhere around the world
Cycads are facing the threat of extinction due to over-utilization by people. People over use and destroy cycads by harvest the palnts and plough cycads in private gardens around the world because their leaves are very beautiful and attractive.

The aim of this article is to investigate the large number of cycads (Encephalartos transvenosus ) in the Modjadji nature reserve.

The Modjadji cycad is one of the largest cycads in South Africa. Encephalartos transvenosus is being protected in Modjadjie Nature Reserve which is found to the north of Tzaneen. People of Balobedu said Encephalartos transvenosus is "Modjadji's palm" and they named it after the Rain Queen. The Rain Queen or Modjadji is the queen of Balobedu . Queen modjadji is areal person and she is known by its power of making rain. Sometimes the Encephalartos plants are commonly called bread palms because the stem is used to make crude bread.

The people of Bolebedu are using these plants as a sacred and they also use it to receive the royal protection from their rain queen that is why they respect these plants. This species is threatened at Modjadji Nature Reserve. The Department of Water Affairs and Tourism (DWAF) plays an important role by conserving cycads plants available at modjadji nature reserve

One can say, cycads are similar to ferns or palms as they have large divided leaves. yes, they are, but not very closely – they’re still more related to palms than either is to us, for example, Cycads are similar to primitive seed plants because the motile sperm produced by living seed plants of cycads are similar to those produced by primitive seed (5).

E. transvenosus is a tree that can reach the height of approximately 6m (2). Cycads fall in the genus Encephalartos and the family Zamiaceae. The plant is not found in large numbers that they tend to grow in small groups. The species has numerous leaves that are arranged in a dense crown. The leaves that can spread up to 2.5 m. E. transvenosus are an evergreen plant. Cycads have large stout trunk and compound leaves. The leaves are light green with fine brown hairs wile the mature E. transvenosus has dark glossy green colour. Its leaves can spread up to 2,5m long. The E. transvenosus is a deciduous plant that produces golden brown cones during late summer. Its trunk can grow up to 45cm Diameter (2). E. transvenosus can survive approximately 100 years.

The species prefers to live in free frost area. It grows well in drained soil, light shade and full sun (4). The cones of E. transvenosus are destroyed by baboons as they occasionally break the immature cones. The seeds are eaten by beetles. The E. transvenosus play an important role in a diet of reptiles that are found in the Modjadji reserve. The management of modjadji reserve are trying to balance and protect this species from reserve. Many animals such as squirrels, monkeys, birds and baboons are attracted by the brightly colour of E. transvenosus. The species is easily propagated from seeds. The species need to conserves from their predators.

Indigenous tribes obtained starch from the stems of E. transvenosus and used it for food. They soaked and grinded the nuts of E. transvenosus in order to remove the nerve toxin although they do not remove the entire toxin from the plants which cause health problem to the people.

The mudjadfji nature reserve is found in the Bolobedu Mountains near Duiwelskloof harbours having some of the most fascinating plants in Southern Africa. One of these plants is E. transvenosus. E. transvenosus is endemic to Limpopo Province and Mpumalanga in South Africa. The reserve covers an area of 530 hectors. E. transvenosus is protected in the Letaba district that receives an annual rainfall of 1500mm (3). The region is a frost free area.

All Encephalartos species are endangered excluding the E. transvenosus because is protected at Modjadji Nature Reserve. Cycads decrease in number as people destroy their habitat. Conservation

The habitats of cycad are being destroyed in the entirety of the world. The forests were cleared for timber and for plant crops e.g. Mexico. In countries where cycads are endemic, plants are being destroyed for housing e.g. South Africa. Currently, there is an increase demand for cycads as the prices of cycads have increased. In South Africa Encephalartos species are selling for thousands of dollars Premium. A botanical garden can remove a cycad from modjadji cycads reserve for research purposes.

There are many people that want to conserve cycads in their own way. If we all work together, and do what is best for the cycads, cycad will no longer decrease in number.

1. Ken Hill, 2004. Introduction to Cycads.[Online].[Cited, 02 March 2007].Available from:

2. Christopher J.2004. Encephalartos transvenosus [Online].[Cited, 27 February 2007]. Available from:

3 Winter J.2005. Encephalartos transvenosus Stapf & Burtt Davy [Online].[Cited, 26 February 2007]. Available from:

4. Wikipedia contributors. Cycads [Internet]. Wikipedia, The Free Encyclopedia; 2007 March 4, 13:16 UTC [Cited 2007 Feb 27].Available from:

5. David L. 2006 Cycads [Online].[Cited 04 March 2007]. Available from:

Linette Netshiheni
CSIR Pretoria
Tell: 012 841 2133
Fax: 012 842 3676


Sea turtles are reptiles species classify in phylum Chordata and order Festudines. Sea turtles are categorised into two families called Dermochelyidae (leatherback turtle) and Chelonnidae (kemp’s ridleys turtles, olive ridleys turtles, green turtles, hawksbill turtles, flatback turtles, and loggerhead sea turtles (1)). Sea turtles are aquatic (ponds, oceans, seas, lakes, rivers) dwellers and lay their eggs on terrestrial (beaches, dunes) (2). The internal organ of turtles is covered by hard (carapace and plastron) shells made of many fused bones called scutes (1). Shells protect the interior of such as heart from bacteria and parasites (1). Turtles have been in the planet since Triassic period about 200 million years ago (2).Sea turtles and their eggs are facing a high risk of becoming extinction in United States (3).

Loggerheads (Caretta caretta) and olive’s ridleys turtles ( Lepidochelys olivecea), were listed as threatened in United States by Endangered Species Act (4 )). Leatherbacks (Dermochely coriacea) green turtles (Chelonia mydas), kemp’s ridleys (Lepidochelys kempii), flatback turtles (Natator depressa), and hawksbill turtles (Eretmochelys imbricata) were listed as endangered in United States by Endangered Species Act (4).

Human activities at the edge of the oceans can have the negative impact on sea turtles and their nesting habitat. Constructions of roads and houses at the edge of beaches have the negative impact on the nesting habitat of turtles. Sea turtles lay eggs and bury them in beach sand so the eggs under the soil can be damaged during the movement of people from one place to another accidentally. Human also harvest shells of the turtles and use them to make jewelleries (5). The lights from the houses built near the sea and night driving disturb the female sea turtles from nesting and return to the sea. It will decrease the natality (birth) of turtles (5). Lights can confuse hatchings on beaches and they will migrate to the land, where they often die of dehydration. Some people harvest eggs of the turtles for the economic purposes while some harvest for the food (6).

Some people believed that the blood of turtles could be used to cure disease. Luis Felipe Lopez has done a research about the blood matter and King Louise XI confirmed that the blood cure his leprosy disease (7). The King says that he used the turtles blood to rub the affected area.

Polluted water by oil spilt, fertilizers, petroleum, and urban run off chemicals have a negative impact on sea turtles. The above-mentioned pollutants can cause diseases and kill sea turtles. They can also kill prey of sea turtles (marine plants and animals) in the oceans and the sea turtles will end up not having food (5). The death of turtles can cause by dumping trash near the beaches. Turtles will die after eating the debris such as plastic bags, tar balls, balloons, pellets, and bottle (5).

Global warming and climate change also have an impact on sea turtles (8). As we know that sea turtles have temperature-dependent sex determination that will increase in global temperature. For those who do not know sex of turtles hatchling while they are still in eggs determine by temperature. Scientists believe that cool temperature produce male turtles while warm temperature produces female turtles (8). When temperature increases, the population of sea turtles become unstable because some turtles hatchling died (8).

All people must follow the laws and regulations to conserve turtles not getting extinction. International laws and agreements, organisations and individuals must cooperate and share the responsibility on conserving turtles. In the United States, the law forbids the purchase of items made from the turtles, for examples, buying jewelleries, and selling the eggs and meat of turtles (5)). The endangered Species Act is the national law that protects sea turtles (5). Other act includes Conservation on International Trade in Endangered Species (CITES) and Marine Turtle Protection Act. The law stipulated that it is illegal to kill the sea turtles, to import and sell the products made by turtles. National Marine Fisheries Services, and Fish and Wildlife Services in United States also protect sea turtles (5).

People have to reduce their disturbances at the edge of the beach for example; they have to decrease impacts and lights in the beaches. People must stop dumping the debris near the beaches and it will help if public awareness is conducted to the communities. Sea turtles need the conservation that should focus on their nesting habitat. Oceans, rivers, and seas also need a monitoring to asses the health of the sea turtles and their prey.


1. Roberson D. Available from: Sea Turtles: families Cheloniidae and Dermochelyidae. 2000 [Online]. September 23. [Cited 2007 February 26]. Available from:

2. Nicholas M. Light pollution and marine turtle hatchlings .2001. [Online]. [Cited March 2]. Available from:

3. Quintanilla E. Hurrcane Emily takes toll on sea turtles. 2007. [Online]. [Cited 2007 March 5]. Available from:

4. Anonymous. Sea Turtle Species of the World. Caribbean Conservation Corporation &Sea Turtle survival league. 1995 [Online]. [Cited 2007 February 28]. Available from:

5. Anonymous. Sea Turtles Threats & Conservation. Caribbean Conservation Corporation &Sea Turtle survival league. 2003. [Online]. [Cited 2007 February 28]. Available from:

6. Anonymous. Marine turtles. Three of the seven existing species of marine turtles are critically endangered. 2007. [Online]. 2007 February 20 [Cited 2007 March 1] Available from:

7. Anonymous. An Insight into Africa’s threatened sea turtles.2002. [Online]. [Cited 2007 March 4]. Available from:

8. University of Exeeter. Scientists warn climate change risk to marine turtles. 2007. [Online]. [Cited 2007 March 2]. Available from:

Lizzy Maluleke
NISL- Ecological Informatics
P O Box 395


Taboos represent traditional social rules that regulate human behaviour [1]. Social taboos (on species and habitat) are also called Resources and Habitat Taboos (RHTs). RHTs include specific species, habitat, clan, temporal, segment, method, life history, and taboos [2]. Social taboos may protect endemic, threatened and keystone species and their habitats [1]. Taboo species may be used for traditional religion or medicinal purposes.

Specific species taboos are comprised of taboos that thoroughly protect plants and animals in space and time. The specific species can be avoided for different uses for example detrimental use, consumption, hunting and killing [3]. The radiated tortoise (Geochelone radiata) is a species native to Southern portion of Madagascar Island. The tortoise populations decreased by 20% after twenty-five years as a result of illegal harvesting for commercial trade and food by the Tandros people [4]. Geochelone radiata was then listed as vulnerable by the International Union for Conservation of Nature (IUCN). Geochelone radiata were protected by Malagasy National law since 1960 and is listed on Convention of International Endangered Trade in Endangered species in 1975 [5] Geochelone radiata is also one of the world rarer species and they were likely to go extinct [5]. The consumption of Geochelone radiata is articulated as taboo [4]

Species such as sacred fig (Ficus religiosa), mountain lion (Felis concolor ) and southern pocket gopher (Thomomys umbrinus emotus) are protected by Hindus’ specific species taboo all over the entirety of
India [3]. Ficus stieligiosa is a keystone mutualist (species that depend on each other for their benefit, when the species that depend on dies, it will also get affected). Ficus stieligiosa is responsible for maintenance of tropical biological diversity. The threatened Felis concolor is a keystone predator that preys on vertebrates which feed on trees species with large seed. Felis concolor may control forest composting by favouring large seeded tree species on behalf of small seeded species. Thomomys umbrinus emotus are essential for moving large quantity of earth and they burrow, scrape and make bare area free from plants [1].

The threatened species are restricted by taboos in different community around the world from using number of birds and reptiles which are classified as threatened by IUCN. The species such as spectacled bear (Tremarctos ornatus); giant armadillo (Priodontes maximus) and giant anteater (Myrmecophoga tridactyla) are protected by taboo in Peru and Achuars of Ecuador. The taboos were enforced by the Achuar within the area [1].

Habitat taboos control access and use of resources in a particular area [2] for example sacred habitat (trees and plant are allowed to grow without any disturbance). Sacred habitats are found in South America for instance Kuna of Pana and Africa, for instance Tanzania. The Mlinga forest reserve of Tanzania has a dam between Muinga and Ukindo Peak [7]. In Tanzania Wanyamwezi (Brachystegia species) are core for spiritual needs of the local people for both ritual and cultural purposes. The burial sites of the chiefs’ are respected and preserved. Conservationists are considering whether sacred groves could be used to promote in situ conservation of endangered species [6].

The Southern range dry spine of Madagascar declined in early 1970s as results of timber harvest, cattle herding and charcoal production [5]. However, small patches of forest were retained for sacred purposes. Small patches were relatively untouched, even in the mainly intensive used area. The sacred forest usually has a sub circular, 300 to 400m in diameter and occasionally contain tomb. However, due to taboo and entering restriction insufficient information is known about the spiny forest [5]

The dam has a big snake. Traditional healers are allowed to use forests for medicinal purposes and dam and other people are prohibited. Trees such as Adansoma digitata and Sterculia opendiculata are not cut because whoever cut these species may be affected by evil spirit. Trees that are found in a water sources and on top of the mountain are not cut. People believe that these trees bring rainfalls and conserve water [7]. As a result, people respect their local taboos and religion by not using dam and cutting the trees.

Temporary taboos prohibit access to resources in time that is daily, periodic, weekly or monthly. The chief of Nkavele village may compel a periodic taboo after cyclones in season of severe drought to conserve food. Similarly, the chief of Nghomu village may place taboos on the use of coconut palms The Ghana people have a daily taboo which is obligated on fishing on a particular weekday for example Tuesday. The similar taboo is also articulated among northwest Newfoundland lobster fishers who avoid Sunday fishing [3].

Method taboos are responsible for controlling method and techniques for removal of species. Fishing using toxin is a taboo because toxins destroy coral reefs. The methods that were articulated as taboo in Oceania in some communities (for example Vanuata) include gill netting, spear fishing during the night and drop line fishing [3]. Different communities of Tuvalu and Kiribati are forbidden to use pressure lantern for dip netting of flying fish. These fishing methods are good for fishers but they may cause over fishing [3].

Life history taboos control the removal of species at vulnerable stages of its life history based sex, age, size or reproductive status [2]. The studies of life history taboo indicated analysis of spawning fish and bird eggs are expressed by taboo. The taboo of hunting fruit bats expressed in daytime settle on trees in midst of villages. As results bats are not overexploited in South India [3].

Segment taboos are responsible for decreasing the rate of exploiting a species [2]. The studies of Amazonian group indicated that segment taboo may decrease hunting pressure of some species with by approximately 50-80% [3] by granting access to specific people for instance chiefs.

Clan taboos usually involve totem (is any entity that stare over clan [8]) species. The clan members of Zaire’s Mbuti are forbidden from consuming totemic species such as leopards, buffaloes and bate antelopes [3]. Several animals are protected through restriction and prohibition in East Usambara forest in Tanzania for example, bushbuck (Tragelaphus scriptus ) and bohr reedbuck (Redunca redunca). The people of Tanzania believe that when they consume meat of these animals, they will have skin diseases. The bird such as Otus species were not killed because people believe that otus are associated with spirit. People also believe that by killing otus, they will encounter misfortune such as death [7]. People may believe the taboo because of their culture or religion.

The ethnic group of West and Central Africa are represented each of their clan with symbol of different wildlife species. To hunt and to eat such species is considered as taboo. The majority of people in Central Africa did not eat or hunt primates because they are closely resemble to human. Young girls and pregnant women were prohibited from eating the meat of monitor lizards, and forest crocodile [9]

The restriction on the use of certain animals, plants and habitat play an important role in conservation. The endemic, threatened and keystone species and their habitats will not go extinct if people continue to use their social taboo to conserve.


1. Colding, J., and C. Folke. The relations among threatened species, their protection, and taboos. Conservation Ecology [online] 1997 [cited 2007 Feb 27] 1(1): 6. Available from:

2. Martinez D. 2001. Final Report for World Funds? U.S. Forest Service Upper Glade National Pilot Stewardship Project. [Online]. [Cited 2007 February 27] Available from:

3. Colding, J., and C. Folke. 2000. The taboo system: Lesson about informal institution for nature management. [online] [cited 2007 Feb 27] Available from:

4. Lingard M, Raharison N, Rabakondrianina E, Rakoarisoa J & Elmgyist. The role of taboos in conservation and management of species: The radiated tortoise in Southern Madagascar [Online] 2003 Jul-Dec [cited 2007 Feb 27] 1(2): Conservation and Society. Avaliable from:

5. Lingard M, Raharison N, Rabakondrianina E, Rakoarisoa J & Elmgyist. Conservation and Society. 2003. The role of taboos in conservation and management of species: The radiated tortoise in Southern Madagascar [Online]. [cited 2007 Feb 27] . Available from:

6. Mgumia F.H and Oba G. Potential role of sacred groves in biodiversity in Tanzania. Environmental conservation [Online]. 2003 [cited 2007 Feb 27] 30(3):259-266. Available from:

7. Kweka D. 2004. The role of local knowledge and institution in the conservation of forest resources in the East usambara. [Online].
[Cited 2007 February 27] Available from:

8. Wikipedia contributors. Totem. [Online]. Wikipedia, The Free Encyclopedia; 2007 Feb 17, 18:22 UTC [cited 2007 Feb 27].
Available from:

9. White L. undated. Integrating conservation& development Central Africa [Online]. [Cited 2007 February 27]
Available from:

Masiya Kedibone
NISL-Ecological Informatics