Restoring the IITA Forest

Deni Bown, d.bown@cgiar.org

Read the Estonian translation by Anna Galovich

IITA lake and forest. Photo by IITA.
IITA lake and forest. Photo by IITA.

In 2010, the International Year of Biodiversity, a new project began at IITA to enhance biodiversity and restore IITA’s Forest. Coincidentally, the United Nations (UN) declared 2011 as the International Year of Forests, and the IITA–Leventis Project is preparing to plant over 30,000 saplings of indigenous tree species this year to restore native forests.

Background
The IITA campus (1000 ha) in Ibadan, Nigeria, now largely within the city limits of Ibadan, was acquired in 1965. The land was mostly bush, interspersed with field crops and 26 villages, whose occupants were relocated. After campus construction and the allocation of fields for crop research, about a third of the site—some 350 ha—was left untouched. In 1987, campus residents created pathways through this regenerating post-abandonment secondary forest, resulting in the Forest Trails we still enjoy today.

After more than 45 years as a reserve, and with continuing loss of forest in southwest Nigeria, this area has become an increasingly important refuge for many plants and animals that were once widespread. Together with an artificial lake at the west margin, the IITA Forest shelters a wealth of animal and plant species and provides a habitat for biodiversity in Nigeria.

year-of-forests-2011

Objectives
The IITA–Leventis Forest Restoration Project aims to:

-Restore the existing forest by removing invasive exotic species, such as Chromolaena odorata, Delonix regia, Gliricidia sepium, Leucaena leucocephala, and Tithonia diversifolia, and replanting the area with indigenous species from seeds, wildlings, and cuttings.

-Protect the IITA Forest against disturbance and theft, in particular, against hunting for bush meat and the collection of medicinal plant parts.

-Catalog the biodiversity of the forested areas, mainly in terms of birds, butterflies, and medicinal plants, and monitor changes.

Junonia cymodoce basking in the sun. Photo by Sz. Safian.
Junonia cymodoce basking in the sun. Photo by Sz. Safian.

-Replant the east bank of the lake with indigenous tree species and carry out research into reforestation techniques.

-Engage in conservation educational activities, especially with young people, to raise awareness of the need to protect forests.

-Form local, regional, and international partnerships in tropical forest conservation, research, and education activities.

Activities
The team of rangers and nursery workers from the IITA–Leventis Project is led by Project Manager John Peacock, Project Coordinator and flora/medicinal plant consultant Deni Bown, and Nursery Manager Olukunle Olasupo. In the first year, over 21,000 seedlings of more than 40 indigenous tree species were propagated. Experimental plots were established to record the effects of different ground treatments on the growth of 10 species. Reforesting the east bank was also started by planting trees grown in their first Tree Seed Project by the International School at IITA and by the Institute’s staff.

In addition to the School’s Tree Seed Project, a Garden Club was started to show children how to grow, propagate, harvest, and value edible and medicinal plants. There are regular activities to engage children in observing wildlife and appreciating the forest. Moves are also under way to found a Youth Explorers’ branch of the Nigerian Field Society which will use the resources and expertise at the IITA campus. Educational displays of medicinal plants, butterflies, and photo archives of birds were exhibited at events, and information, both printed and electronic, is provided for the numerous visitors.

Together with the Security Unit at IITA, the team also improved the protection of the Forest.

Ibadan malimbe, an endemic bird species in Nigeria. Source: Leventis Foundation.
Ibadan malimbe, an endemic bird species in Nigeria. Source: Leventis Foundation.

Catalogue of forest resources
The IITA Forest is an internationally acclaimed Important Bird Area (IBA). Since March 2010, over 200 bird species have been identified during surveys by Shiiwua Manu, Phil Hall, John Peacock, Adeniyi Taiye, and Matt Stephens. Similar baseline surveys were carried out for butterflies by Szabolcs Sáfián, Robert Warren, and Oskar Brattström, and brought the total identified in the IITA Forest to 220. Deni Bown has to date recorded 431 plant species at IITA; of these, 382 have medicinal uses.

Flagship species
For many people, the Forest is a place of mystery and beauty but something they may not know much about. By targeting conservation efforts on spectacular species, their interest can be focused. The Project has three flagship species: the Ibadan malimbe, Malimbus ibadanensis, an endangered bird found only in the Ibadan area; the iroko, Milicia excelsa, one of Nigeria’s most important timber trees; and the “PG plant”, Pararistolochia goldieana, a liana (a woody vine) that produces the largest flower in Africa.

Pararistolochia goldieana, a woody vine that produces the largest flower in Africa. Photo by O. Adebayo, IITA.
Pararistolochia goldieana, a woody vine that produces the largest flower in Africa. Photo by O. Adebayo, IITA.

The Iroko is of major economic importance but cannot be grown successfully in plantations. The only place where it is now safe from being felled is within the IITA campus.

Likewise, the Ibadan malimbe and PG plant are totally dependent on the IITA Forest for survival.

Over the past 50 decades, the loss of tropical forests in Nigeria has been catastrophic, giving this fragment in IITA considerable importance. Increasing its extent and biodiversity is part of IITA’s new initiative to conserve biodiversity and create an African Science Park or Innovation Africa™. These are valuable resources for local interests and the wider scientific community.

why-do-tropical-forests-matter

The butterflies of IITA

Robert Warren, robertdavidwarren@yahoo.co.uk

Charaxes imperialis. Photo by IITA.
Charaxes imperialis. Photo by IITA.

IITA boasts a wide range of butterflies. Knowledge about the diversity of these species, however, is incomplete. For instance, a preliminary survey conducted from 2002 to 2009 has confirmed the presence of 149 butterfly species. The actual number could fall somewhere in the range of 250 to 400.

A survey carried out in a directly equivalent location (Olokomeji Forest Reserve) in the late 1960s found 267 species, with quite limited collecting inputs (estimated total >450). A more complete survey at Agege, near Lagos in southwestern Nigeria, found more than 380 species. This location is in the moist evergreen forest zone, and is fairly comparable to the secondary nature of the IITA forest.

Completing a survey at IITA would yield information useful for conservation. The fact that the IITA forest is small and now isolated would allow the assessment of pressures on extinction. Despite the enormous destruction of West African forests to date, records show that butterfly extinction has yet to occur when viewed on a regional scale.

While the primary consideration for survival will be the presence of the host plants, there is also a consideration of the range required for survival. Knowledge of the total species population within IITA and specific species present could be likely to provide answers on the cut-off point where the range is too small for survival of certain species groups.

The IITA forest is also an important conservation target itself because of its location. It is quite possibly the westernmost representative of semi-deciduous forest on this scale before the Dahomey gap. Attempts to locate equivalent forests within Nigeria to the west of IITA, guided by satellite imagery, yielded only one small, unprotected patch (5 km west of Tapa). Forest reserves have all but disappeared. Several butterfly species (e.g., Liptena ilaro, Euriphene kiki, Axiocerses callaghani) found near IITA have not been seen elsewhere, pointing to the biogeographical importance of such habitats. If results eventually show that the IITA forest is indeed too small to allow the survival of all the species that should be present in an equivalent forest type, it will nonetheless remain an important refuge.

Display cases of all but a handful of the 149 species observed to date have been donated to IITA to promote further interest.* A specimen of the very rare species Melphina noctula was found at IITA (there are only three in the Natural History Museum), and has been donated to the African Butterfly Research Institute in Nairobi, Kenya.

An in-depth study of the IITA butterflies would be of international interest and importance because very few such surveys have been completed in Africa. Comparison with our knowledge of the fauna of western Nigeria could shed light on the importance of a forest such as IITA’s for the long-term survival of species. It could be one of the localities proposed for studying the survival of the butterflies between now and 2100. Finally, it could show if new species are added as the forest matures from its secondary status over time.

*Specimens were collected, identified, mounted, and donated recently by the author to IITA. These are currently on show at the IITA International School in Ibadan, Nigeria. The author is a buttefly expert who came to Nigeria at the age of 4 months. He has been surveying butterflies all over Nigeria and also at IITA since 2002.

A research park for Africa

John Peacock, j.peacock@cgiar.org

The IITA campus is a rich center of biodiversity. Because of the protection and nonexploitation of a patch of secondary forest, lakes, and other natural resources in the area, it represents a wealth of flora and fauna that are not common in other parts of Nigeria.

IITA campus, Ibadan, Nigeria. Image from Google Maps.
IITA campus, Ibadan, Nigeria. Image from Google Maps.

IITA was established in April 1967. Earlier in October 1965, approximately 1,000 ha of land were acquired, lying between Ojo in Ibadan town and Moniya villages. The land was covered mainly with oil palms, cassava, maize, cocoyam, and a variety of indigenous trees and climbers.

Today, 43 years on, the area is taken up by research, administration, and residential buildings, lakes, experimental plots, and 350 ha of valuable secondary forest. An arboretum was established in 1979 containing 152 different tree species; 81 of them are indigenous. In addition, the residential and administrative areas of IITA were extremely well landscaped with a diversity of both indigenous and exotic trees. Many of the original hardwood trees were left in situ.

Young Milicia excelsa (Iroko). Photo by J. Peacock.
Young Milicia excelsa (Iroko). Photo by J. Peacock.

Although protected, the forest is still a degraded secondary forest. It is basically four layered, made up of a discontinuous emergent canopy dominated by Milicia excelsa (Iroko), Celtis zenkeri, Terminalia superb, and Antiaris africana; a tree canopy made up of Blighia sapida, young Ceiba pentandra, Entandrophragma angolense, and Ricinodendron heudelotii as the more frequent woody plants. The shrub layer is composed mainly of Newbouldia laevis and Baphia nitida with seedlings and saplings of typical canopy emergents such as Mammea africana. The herb layer is highly diverse containing members of the family Orchdaceae and some Poaceae and Chromolaena sp. in the more open areas (Hall and Okali 1978, 1979).

The IITA forest provides a good habitat for a great number of different insects and birds. It is one of the Birdlife International Important Bird Areas (IBA) with 350 species, including the Ibadan Malimbe, Malimbus ibadanensis, which is endemic to this region.

Knowledge about the diversity of butterfly species at IITA is incomplete. A preliminary survey conducted by lepidopterist Robert Warren in 2002−2009 has confirmed the presence of 149 species (See Warren, this issue). This figure is considered low and could be as high as 400.

Pararistolochia goldieana. Photo by IITA.
Pararistolochia goldieana. Photo by IITA.

In December 1987, a group of enthusiastic volunteers from IITA embarked on carving out a nature trail in the forest. Many useful plant species including herbs, medicinal plants, fiber-producing plants, and fruit and timber trees can be seen from the trail. The most spectacular is a climber with a long name and a huge (40 cm diameter and 50 cm length) dark-red flower called Pararistolochia goldieana, which belongs to the family Aristolochiaceae.

The rich biodiversity of the campus is also influenced by its nine lakes. The largest is approximately 70 ha. A dam (The John Craig Dam) was constructed in 1969 and impounds water from the Awba River which runs through the Gunwin watershed. This lake is home to various varieties of fish, aquatic weeds, and birds.

Currently there are many fish in the nine lakes and ponds. Records show that the largest lake was stocked with a wide variety of species. The dominant ones are the African Catfish (Clarias gariepinnus), Nile Perch (Lates niloticus), Slapwater (Heterotes niloticus), and various Tilapines (Oreochromis niloticus, Tilapia zilli, etc.). But a wide variety of other species are present, e.g., Gymnarchus niloticus, Hepsestes odoe, and Channa obscura. There is also a diversity of aquatic weeds, Nuphar spp. (water lily), Azolla sp. (water fern), Potomogeton sp., Typha sp. (bulrush), and Lagarosiphon cordofanus Caspry. L. cordofanus Caspry is uncommon and this may be the only known occurrence in Nigeria (Adeniyi Jayeola, personal communication).

Despite the water and forest habitat, the resident level of mammalian fauna is low. The cane rat or grass-cutter, duiker, mongoose, potto, tree hyrax, civet, and the giant Gambian rat can be seen. Others are the bush-tailed porcupine, squirrels, and small antelopes. Amphibians, lizards, and snakes are also common but have not been studied or documented.

Fruit bats flying over a Ceiba pentandra tree (Yoruba local name: osun papa), IITA. Photo by IITA.
Fruit bats flying over a Ceiba pentandra tree (Yoruba local name: osun papa), IITA. Photo by IITA.

However, there is a large population of straw-colored fruit bats. The flying foxes (Eidolon helvum) form large colonies in the IITA forest. They are the second largest West African bat with a wing span of up to 953 mm. Adults can weigh up to 350 g. They roost conspicuously in the open, covering hectares of treetop branches in the IITA forest and arboretum. An important food for these bats is the fruit of the Iroko tree (M. excelsa). The Iroko produce finger-sized fruits that resemble mulberries. Each fruit contains an average of 80 small, tomato-like seeds which are then transported away from the parent tree. Iroko ranks as one of Africa’s most valuable hardwood trees.

Why is IITA so concerned about its secondary rainforest, indigenous trees, and its rich biodiversity? Deforestation is a serious problem in Nigeria that currently has one of the highest rates of forest loss (3.5%) in the world, translating to an annual loss of 350,000–400,000 ha of forest land (See Ladipo, this issue). Since 1990, Nigeria has lost 6.1 million ha or 35.7% of its forest cover. These figures give Nigeria the dubious distinction of having the highest deforestation rate of natural forest on the planet, and the lowest percentage (2.4%) of rainforest remaining in any African country.

The IITA campus is one of the few reserves in Nigeria where valuable and rare indigenous trees, such as the Iroko, are safe from poachers. Today there is only one specimen of Parkia bicolor in southwestern Nigeria; this one tree is on the IITA campus.

Recently the Director General of IITA, Hartmann, announced that the IITA campus and all it contains will become an African Science Park. This decision is most timely, coming during the International Year of Biodiversity. This will create a more diverse scientific community which could include agriculturalists, ornithologists, lepidopterists, ecologists, foresters, botanists, invasion biologists, and conservationists.

In the future, the IITA campus could be used as a research site for reconciling increasing agricultural production in the tropics and the conservation of biodiversity. IITA has embarked on seed collecting and propagation of indigenous trees to develop an in-situ conservation program for indigenous trees of West Africa. It is also working with scientists at the A.P. Leventis Ornithological Research Institute (APLORI); Centre for Environmental, Renewable, Natural, Resources Management Research and Development (CENRAD); Forestry Research Institute of Nigeria (FRIN); the University of Ibadan; and the Royal Botanical Gardens, Kew to ensure that its rich biodiversity will be conserved for many generations to come. This new initiative at IITA will be used to educate and encourage others in Nigeria to preserve these valuable rainforests.

References
Hall, J.B. and D.U.U. Okali. 1978. Observer-bias of complex in a floristic survey of tropical vegetation. Journal of Ecology 66: 241–249.

Hall, J.B. and D.U.U. Okali. 1979. A structural and floristic analysis of woody fallow vegetation near Ibadan, Nigeria. Journal of Ecology 67: 321–346.