An Overview Of Our Solution
A study in 1.2ha degraded watershed in Ologbo Forest Reserve, Nigeria. The plot was rid of the grass dominated vegetation leaving the relic trees/shrubs. Using the framework species & maximum diversity method, 1336 seedlings of 5 indigenous trees were planted. Three improved cassava varieties were inter-planted at 1.2m x 1m. Cultural activities (e.g. weeding) were undertaken. The cassava crops were harvested/replanted in 2006, second harvest was in 2007. Growth data were collected. At 30 months after planting (MAP), the relic species population increased by 5% while height of introduced taxa averaged 300m. At 36MAP, plant succession reversed from entirely grass- to broadleaved herbs – perennial grass association. At 54MAP Khaya grandifoliola and Nauclea diderrichii attained average height of >4.8m.
Who is this solution impacting?
Community Type
Rural
Additional Information
- Population Impacted:
- Continent: Africa
General Information
Organization type
individual
Ecosystem (select all that apply)
Forests
Population impacted
Empirical investigation
Challenge
Size of agricultural area
1.2ha
Production quantity
Biodiversity restoration/Ecosystem services/15 – 17tons/ha
People employed
9 people
Solution
Describe your solution
Enrichment planting/Assisted natural regeneration involving cassava & some indigenous forest trees was used to rehabilitate a degraded portion of the catchments of a small river in 2005. The 1.2ha plot was rid of the grass-dominated fire-climax vegetation leaving all relic trees/shrubs. Using the framework species and maximum diversity design, 1336 seedlings and wildlings of some crops were out-planted at 3m x 3m. Cuttings of three cassava varieties: Tropical Manihot Series (TMS) 30572, 30555 & 4(2) 1425 were later inter-planted at 1.2m x 1m. Weeding, fire-tracing, beating-up, pruning and mulching were undertaken. In line with local farming practices, the cassava varieties were harvested and replanted in 2006 while the final crop was harvested in 2007. At 30 months after planting (MAP), total tree population (relic and introduced species) increased. At 36MAP, plant succession at the plot reversed from being entirely grass- to broadleaved herbs and perennial grass association with Chromolaena odoranta and Panicum maximum. At 54MAP tree population was 1384 while some Khaya grandifoliola and Nauclea diderrichii species reached average height of >4.8m. The dominance of the Chromolaena odoranta weed over perennial grasses + with the emergence of 1 primary tree colonists Trema orientalis & Musanga cecropoides within a span of four years suggest irreversible build-up of eco-resilience culminating in natural successional trend and recovery of biodiversity at the site.
Implementation
Describe your implementation
The plot having been rid of the grass-dominated fire-climax vegetation leaving all relic trees/shrubs, a number of indigenous species seedlings were planted side by side three improved cassava varieties using the framework species and maximum diversity design. Cultural activities – weeding, fire-tracing, beating-up, pruning, mulching were carried out during the study. Weeding was carried out manually 18 times during the first two years. To keep out fire during the dry season, mulching and fire tracing were done twice – September and December. The cassava varieties and relic trees at the site provided an enabling environment for the young tree seedlings, particularly during the dry season. The harvest and replanting of cassava were done to mimic the extant cropping practice which is common among the subsistence farmers in communities who had hitherto depended on Ologbo Forest Reserve for their livelihood. Although attention was mainly focused on the rehabilitation of the degraded landscape, the yield from the first cassava harvest (14metric tons) in 2006 was more than the outcome from the second/final harvest (12metric tons) in 2007. The canopies of the relic trees and different cassava varieties instigated forking of the seedlings – to the extent that over 10% of the total stems of the introduced taxa had bifurcated stems. We collected abundance and growth data on introduced species and relic trees/shrubs while assessment of natural succession was somewhat anecdotal. We engaged six labour and ensured that they were fully committed by providing adequate remuneration. Our team did close evaluation and monitoring of activities at the project site. One critical issue which was given prompt attention was the long spell of dry season that preceded the establishment of the experiment site. The seedlings strived and grew optimally under the cassava for two years. When the cost of hand weeding became too high, we resorted to locating and releasing natural regeneration
External connections
The project was originally designed as a tree planting exercise for 2005 but was later converted to an experimental site after the ceremony was concluded. Two volunteer staff – an agriculture extension officer and another with expertise in farmers’ cooperatives – of the State Ministry of Agriculture and Natural Resources were drafted into the project as members of the project implementation team. The State Ministry of Environment and Public Utilities provided the planting stock from its established nursery where the seedlings were nurtured. It also provided tools and materials as well as funds for the payment of salaries of four labour during the first two years; subsequently when two labour were engaged on part time basis. The Ministry of Agriculture provided the improved cassava varieties at subsidized rates. The money realized from the sale of cassava was ploughed back and used for the payment of emolument of some labour. Taungya farming system was introduced to Nigeria in the 1920s. The system was a land hunger-driven initiative in which a portion of land (ca. 1 acre) is allocated to a farmer in a forest reserve by the Forestry Department (FD). The farmer (allotee) prepares the land and cultivates his arable crops side by side forest tree seedlings (that were supplied by the FD) for one or two years; and after harvesting his arable crops, leaves the site thus giving room for the forest trees to grow as plantation made up of single or mix stand.
Results
What is the environmental or ecological challenge you are targeting with your solution?
Conversion of forest land to diverse agricultural production systems and development of infrastructure, e.g. oil exploration; illegal and unsustainable logging, wildlife poaching, slash and burn/nomadic agricultural practices and associated wild fires, soil erosion, environmental pollution and climate change and associated externalities. Ruination of ecosystem services, including species erosion and biodiversity loss; dismantling forest dependent people’s livelihood systems; reduced primary productivity, low soil fertility, recurrent fire and increased susceptibility to fire, small-holder itinerant farm family dependence on customized traditional hand tools for cultivating arable land; total reliance on rain-fed agriculture; subsistence, risk averse and low input resource driven practices. Weather adverse conditions and huge harvest losses; poor cropping patterns; weak tenure and land use systems.
Describe the context in which you are operating
Human population increase is the main socio-economic driver of forest/agricultural land degradation. Rainfall amount/distribution has declined considerably during the last five decades. Cassava is Nigeria’s most common and adaptable staple food crop which is highly resilient & can grow in most diverse climatic conditions; performs optimally (output) in marginal lands as well as nutrient deficient and impoverished soils. It is ubiquitous, easily processed into assorted food products and acceptable across diverse cultures. IITA has developed several high yielding, early maturing and disease-resistant varieties of the Tropical Manihot Series (TMS) which produce low to medium stems; early branching and canopy development; Ologbo Forest Reserve (OFR) dependent communities engage in arable farming, artisanal fisheries, itinerant timber processing and petty trading. Population range from 200 in Ikara to 1,200 in Ologbo. Over 90% of OFR has been de-reserved and converted to other land uses.
How did you impact natural resource use and greenhouse gas emissions?
The introduced species reaction to canopy shade as well as trends in succession among secondary colonists and weed species were largely numerical and somewhat anecdotal. Growth data of all introduced species were summed for all three most abundant taxa across sub-plots before calculating the relative growth rate and annual absolute height increment. Rank-abundance curve was constructed using total number of stem recorded for both relic and introduced species. Of the 1336 seedlings planted in 2005, 76 or 13.5% developed forked stems (or double leaders). Nauclea diderrichii accounted for 75.6%, Khaya grandifoliola (20.4%) and Entandrophragma angolense (3.9%). Within sub-plots, spontaneous bifurcation among the introduced taxa was most widespread under TMS 4 (2) 1425) cassava variety in sub-plot 5 followed by sub-plots 6 and 7 which had TMS 30572 and (25) 1425 cassava varieties respectively. By the fourth year when the relic species and introduced taxa had attained substantial height, small mammals and avi-fauna population increased at the experimental site – particularly with regards to nesting sites.
Language(s)
English
Water
The study which was conducted in the 1.2ha plot located on the degraded Agbaa stream catchments (pH 5.2, organic carbon 0.7%, clay 8%, silt 3% and sand 89%) restored biodiversity around the river which provides drinkable water to some of inhabitants, particularly farm families. The project did not only improve the fertility of the soil in the watershed, the flow status of the stream which was hitherto seasonal was restored to perennial flow & water quality and volume improved considerably.
Food Security/Nutrition
The rehabilitated site offered mutually reinforcing conservation and livelihood benefit options to peasant families, small holder investors and individuals in Ologbo town and peripheral communities. The site provided reliable supplies of food, fuel wood, Non-timber Forest Products (NTFPs). Besides, it created feeding, roosting and nesting sites for birds and small mammals. The return from cassave sales was considerably high when compared to pre-experiment yield from the same site.
Economic/Sustainable Development
The improved ecosystem services enhanced livelihood system of rural populations who depend on the forest reserve. Some ecosystem services (i.e. vegetation cover and resultant erosion control, food , improvement of river water volume and purification and fuelwood) might have been generated fairly promptly following restoration of eco-services. Besides, it created appropriate habitat conditions for seed and seedling banks & regeneration, growth & establishment of indigenous species.
Climate
The year 2005 recorded the least rainfall amount (1595mm) between 1960 and 2010. The climate in Ologbo Forest Reserve is governed by two major seasons: Wet & Dry. Rainfall pattern is bi-modal with 2 peak seasons, average rainfall data for the period 1960 to 2010 was 2176mm. While average rainfall has been on a gradual decline, 2005 (when project commenced) recorded the least rainfall. Relative humidity is 83% and average maximum and minimum temperatures of 350C and 230C respectively.
Sustainability
Seed fund from government drove project activities during the first two years. Fund is needed to carry out rehabilitation work involving forest trees and arable crops.
Return on investment
It took Two thousand six hundred and fifty US Dollars to implement the activities in four years. Comparatively return on investment is high. Project is cost effective.
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Replication and Scale
How could we successfully replicate this solution elsewhere?
To successfully replicate the results of this investigation, it will be imperative to adopt participatory approach involving all stakeholders – government, communities, civil society and research institutions. Besides, specific site/climate characteristics, community and individual needs – including livelihood, arable crops, forest trees, etc. should be taken into consideration. Although this has not been done on a large scale before, it has a high prospect for resolving issues of landscape/environmental degradation and rehabilitation of marginal lands/ecosystems. The key stakeholders will include: corporate organizations (Presco Plc, government Ministries, Departments and Agencies (Agriculture and Natural Resources and Environment and Public Utilities). A modest cost of One thousand two hundred US Dollars ($1200) per hectare can conveniently rehabilitate a forested land turned fire-climax ecosystem. This will depend on the possibility of partners support.