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Forest plantations on Imperata grasslands in Indonesia - Establishment, silviculture and utilization potential
... Much lower volume production ranging from 2.03 to 4.01 m 3 ha −1 for different A. auriculiformis provenances at the age of 3 years are also reported (Mbwambo et al. 2004). The high volume production of A. crassicarpa from PNG has been widely reported (Thepphavong 1997, Otsamo 2001. Good performamce of A. crassicarpa in volume production is attributed to its advantages in good growth in diameter and height at the study site. ...
... The results showed variations in basic wood densities among species/provenances. Variations in basic densities amongst Australian-PNG acacias are reported by various authors (Ali et al. 1997, Clark et al. 1991, Otsamo 2001. For example, in Malawi, basic density for A. crassicarpa ranged from 524 kg m −3 to 607 kg m −3 (Ngulube et al. 1993). ...
This study to compare performance of three Australian–Papua New Guinean Acacia species/provenances (A. mangium, A. auriculiformis, A. crassicarpa) and A. julifera was conducted at Kongowe, Kibaha, Tanzania. Species/provenances were evaluated for survival, growth (diameter, height and volume), wood basic density and wood biomass. The trial was laid out using a randomised complete block design with three replications of 22 treatments (species/provenances). Data for survival, diameter at breast height and height was collected at ages 2 and 4 years from the nine inner-plot trees. Six defect-free trees from each treatment were selected at random for volume, wood basic density and biomass measurements. Results showed significant differences in survival, height and diameter growth among species/provenances at all assessment occasions. Average untransformed survival at 4 years ranged from 16.0% to 93.3%. Acacia crassicarpa from Bensbach, Papua New Guinea (PNG), had the largest diameter (13.9 cm) and A. crassicarpa from Bimadebum, PNG, had the largest height (12.6 m). Volume production and wood biomass differed significantly (p < 0.001) among species/provenances. Acacia crassicarpa from Bensbach, PNG, had the highest volume (58.7 m3 ha–1) and wood biomass (53.4 t ha–1) while A. mangium from Kongowe, Tanzania, had the lowest height (4.6 m), volume (1.92 m3 ha–1) and wood biomass (2.7 t ha–1). Acacia mangium from Claudie River, Queensland, had the highest basic density (610.6 kg m–3) while the accession from Bituri, PNG, had the lowest (375.2 kg m–3). Ordinal ranking indicated that the three best-performing Australian–PNG Acacia species/ provenances were A. crassicarpa from Bimadebum, PNG; A. crassicarpa from Bensbach, PNG; and A. auriculiformis from south of Coen, Cape York. The three poorest species/provenances were A. mangium from Kongowe, Kibaha, Tanzania; A. julifera subsp. julifera from Ipswich, Queensland; and A. mangium from Balimo, PNG. The best-performing species/ provenances are recommended for planting in Kongowe and other areas with similar ecological conditions.
... A review of literature on typical Imperata grassland in oil palm growing regions reveals AGBs ranging from 3.8 Mg ha -1 to 23.0 Mg ha -1 (Hartemink, 2001;Hashimoto, Kojima, Tange, & Sasaki, 2000;Holmes, Lemerle, & Schottler, 1980;Lasco et al., 2000;NRI, 1996;Otsamo, 2001;Roshetko, Delaney, Hairiah, & Purnomosidhi, 2002;Wibowo, Suharti, Sagala, Hibani, & van Noordwijk, 1997). The average AGB of 11.2 ± 7.3 Mg ha -1 obtained from these data and applied in the following calculations is distinctly higher than the given IPCC range. ...
... The process by which invasive grasses replace forest is closely linked to fire, which kills young trees and seedlings but allows grasses to survive . Annual burning of grassland (Andersson, Michelsen, Jensen, & Kjoller, 2004;Otsamo, 2001;van der Werf, Randerson, Collatz, & Giglio, 2003), a linear development of the AGB and insignificant BGB fluctuation is assumed for the estimations. Based on the above values and assumptions, the timeaveraged biomass of grassland (above and below ground) in oil palm suitable environments of the humid tropics is 26.7 ± 17.4 Mg ha -1 . ...
Estimates of emissions indicate that if tropical grassland is rehabilitated by oil palm plantations, carbon fixation in plantation biomass and soil organic matter not only neutralises emissions caused by grassland conversion, but also results in the net removal of about 135 Mg carbon dioxide per hectare from the atmosphere. In contrast, the emission from forest conversion clearly exceeds the potential carbon fixation of oil palm plantings. Forest conversion on mineral soils to promote continued oil palm mono cropping causes a net release of approximately 650 Mg carbon dioxide equivalents per hectare, while the emission from peat forest conversion is even higher due to the decomposition of drained peat and the resulting emission of carbon oxide and nitrous oxide. The conversion of one hectare of forest on peat releases over 1,300 Mg carbon dioxide equivalents during the first 25-year cycle of oil palm growth. Depending on the peat depth, continuous decomposition augments the emission with each additional cycle at a magnitude of 800 Mg carbon dioxide equivalents per hectare.
The creation of ‘flexibility mechanisms’ such as the clean development mechanism and emission trading in the Kyoto Protocol could incorporate plantations as carbon sinks in the effort to meet emission targets. Thus, for the oil palm industry, grassland rehabilitation is an option to preserve natural forest, avoid emissions and, if the sequestered carbon becomes tradable, an opportunity to generate additional revenue.
... In some cases, in accessible mineral soil areas, if the cleared area is not guarded, local communities will invade and initiate low-intensity agricultural production in these areas. If soils become degraded and fire is applied repeatedly to clear fields, this may lead to invasion by noxious weeds, such as Imperata cylindrica, which already render over 8 million hectares of Indonesia as 'wasteland' (Garrity et al. 1996;Otsamo 2001). As discussed later, a large proportion of concession area is on deep tropical peat soils, where forest regeneration is particularly slow, and when exposed to fire, clearance will be followed by a prolonged state of sedge (Cyperaceae) grassland (Giesen 2004). ...
... Most assessments of restoration projects have found modest levels of survival but with survival rates varying greatly both between species and planting habitats (Sampaio et al., 2007, Palma and Laurance, 2015, Wheeler et al., 2016. This is particularly true for areas dominated by grasses such as Saccharum spontaneum and Imperata cylindrica, which are strong competitors against small seeded, light demanding tree species and are highly susceptible to fire, further retarding forest regeneration (Otsamo, 2001, Hooper et al., 2002. Dense bamboo thickets have similarly been shown to inhibit the regeneration of tree seedlings (Griscom and Ashton, 2003, Taylor et al., 2004, Lima et al., 2012). ...
... However, this study focused only to those block planting system plots of the two Shorea species with different spacing distance. Direct planting of dipterocarps and other primary forest species especially on Imperata grasslands have largely been unsuccessful because of slow growth and high mortality arising from their shade and moisture requirements (Otsamo et al. 2001). ...
Subiakto A, Rachmat HH, Sakai C. 2016. Choosing native tree species for establishing man-made forest: A new perspective for sustainable forest management in changing world. Biodiversitas 17: 620-625. Establishment of tree plantation on degraded lands and forest clearly favored some exotic species such as Gmelina arborea, Acacia, and Eucalyptus. High productivity, less harvesting time, and deeper silvicultural knowledge are the beneficial factor for choosing those exotics species. However, the use of a wide variety of native tree species becomes more significantly important in reforestation projects due to the greater biodiversity benefits and wider
environmental services. This research was carried out as a multiyear observation and continuous experiment to value how native tree species can be prospective alternatives in providing and supporting human need. The performances of two native Indonesian Shorea species, Shorea leprosula and Shorea selanica, were evaluated at a dipterocarp planting trial in two different sites in Indonesia. Growth data was obtained from 15 and 17 years old plots, twelve 100 m X 100 m square plots on mineral soils (Gunung Dahu Experimental Forest/GDEF, Bogor) and eight resembled plots on frequently flooded peat land (PT. Arara Abadi/PT. AA, Riau). Survival rates were varied, ranged from 36-77%, diameter at breast height from 13.7-24.9 cm, tree height from 10.8-16.9 m, mean volume from 0.119
m3/tree-0.567 m3/tree, and total volume from 79.420 m3/ha-215.412 m3/ha. Growth rates of planted saplings were affected by species, site and spacing distance. The development of man-made dipterocarps forest in the tropic, especially in South East Asia can be as prospective as developing an exotic fast growing plantation. Eventhough in situ conservation would give the most benefit in conserving genetic resources of native tree species, establishing man-made dipterocarp forest still have higher environmental value than using exotic tree species such as acacia. Moreover, establishing man-made dipterocarp forest is considered more environmental friendly and possess lower to no risk of species invasion compare to those of developing exotic trees plantation.
... Considering that the width of the critical land as well as the rate of the land degradation are highly increased, then the efforts to restore and to suppress the rate of the critical land have become an urgent requirement. Conservation efforts of soil and water physically, chemistry and biology have often been carried out (Nugroho, 2000;Otsamo, 2001;Nurtjahya et al., 2008;Ilyas, 2012;Asir, 2013), but the results were not yet maximal. The main error prominent of these activities is less coherence of activities and sectors, and not focused the actual problem at its source (Nugroho, 2000). ...
The objective of the present study was to examine the growth responses of Acacia mangium (mangium) and Paraserianthes falcataria (sengon) seedlings growing on different soil origin under nursery condition. This study was started in September 2012 and terminated in March 2013. The seedlings were grown from seeds sown in a plastic box filled with sterilized sands. One week after sowing, the seedlings were transplanted into polybags contained sterilized soils originated from secondary forest, Imperata cylindrica grassland and ex-coal mining. The number of all seedlings were 180 seedlings consisted of 3 different soils, 2 species of seedlings with 10 seedlings replicated 3 times. Assessment was conducted one week after transplanting, then subsequently monitored every 2 weeks, except dry weighing and counting nodules were performed at the end of the study. A completely randomized design was used in this study. The data was analyzed using Costat software. The study resulted that the different of soil origin influenced on all growth variables of mangium and sengon of 4.5 months old. The survival rate of seedlings, height and diameter increments, dry weight and root nodules were better in both species of seedlings growing on soil originated from secondary forest and Imperata grassland compared with the soil from ex-coal mining. But the survival rates of sengon seedlings were higher than that of mangium on these three soils. The highest dry weight of sengon seedlings was achieved on soil originated from secondary forest. In the present study, soil originated from secondary forest increased more in weight of shoot than root, so that the shoot-root ratio was unbalanced more than one. Based on the results of this study, it is recommended that soil from secondary forest and Imperata grassland can be used as growing media for mangium and sengon seedlings in the nursery.
... 12 The Reforestation Fund obliged companies to deposit a fee for each cubic meter extracted from the forest, with the assumption that the amount could be reclaimed after reforestation . In the 1980s the reforestation deposit was 4 USD per cubic meter, increased to 7 USD in and 10 USD in 1990 (Otsamo, 2001). The mechanism has not been an effective tool, as replanting was generally more expensive than the refund and many business actors preferred to pay the deposit and not replant their concession sites (Dauvergne, 1994, p. 514). ...
Forest plantations have been an important land-use pattern in Indonesia for centuries. Yet the role of timber plantations, their specific goals, perceptions, actors involved, and management systems had been redefined in the past and they continue to evolve today. It is important to understand the driving forces and historical trends shaping timber plantations in Indonesia in order to critically reflect on their changing roles in the forestry sector. This article traces the development of Indonesian forest plantations through time by categorizing them into paradigms. Proposed explanatory framework helps to see the historical legacies in the Indonesian plantation sector. The identification of historical plantation modes is based on a literature review while current approaches and specific policy instruments are discussed based on exploratory empirical case-study material from three Indonesian forest plantation estates (involving joint forest management, community forest management and large private timber company). The historical review shows a range of continuities and helps to explain the problems forest plantations in Indonesia face today. It points to socially-oriented community forest management as highly praised by its stakeholders, able to improve rural livelihoods and secure environmental benefits.
... According to a study by (Otsamo 2001), there is between 8.6 and 64.5 million ha. of alang-alang grassland in Indonesia alone, although this upper limit seems exaggerated. The same study quotes another source that puts the amount of tropical fallow land at 20 million ha. ...
... Einer Studie von (Otsamo 2001) sowie Reinhardt et al. 1999 dokumentiert. ...
... In addition to P deficiency (e.g. , Otsamo 2001, Wan Rasidah et al. 1988, K can also act as a major limiting factor to growth and productivity for A. mangium (Simpson 1992in Srivastava 1993. Since droughts may become more sever and frequent in the future, it is crucial to pay more attention to K uptake efficiency in A. mangium stands. ...
Nutrient inputs via litterfall and associated nutrient accumulations and releases in the litter layer were investigated in 7-year-old Acacia mangium Willd. plantation stands in Indonesia. Annual N, Mg, Ca and K inputs via litterfall were 230-235, 21-26, 157-179 and 131-157kg ha ⁻¹ yr ⁻¹, respectively and the contributions of phyllode litterfall to these nutrient inputs were over 60%. Nutrient inputs via litterfall increased from dry to wet seasons being strongly associated with reproductive litterfall inputs as well as phyllode litterfall inputs. Annual mean N, Mg, Ca and K accumulations on the forest floor were 172-235, 12-14, 52-88 and 42-47kg ha ⁻¹, respectively. There were no clear seasonal variations in nutrient amounts on the forest floor. The peak of mass loss of phyllode litter was observed in the late wet seasons, and its seasonal change was coincided with the rainfall seasonality. Reflecting mass losses of reproductive and twig litters, however, seasonal variability in mass loss of whole litter became more complex. Nitrogen and Mg releases from litter layer tended to increase in the late wet seasons being affected by the retarded releases of these nutrients from fleshly fallen litters in addition to the increased mass loss of phyllode litter in the periods. Calcium releases from litter layer showed no significant seasonal variations reflecting the irregular seasonal changes in Ca release from twig litter rich in Ca. Meanwhile, the seasonal variation in K release from litter layer coincided with the seasonal changes in K inputs via litterfall.
... In plantations it has proven to be very site-adaptable and shows satisfactory growth even on eroded, rocky, thin mineral and deeply weathered soils (Srivastava 1993;Nhan and Duc 1997;Norisada et al. 2005;Patil et al. 2012), on a range of soil types (Duguma et al. 1994;Ghosh and Verma 2006;Nykvist et al. 1996;Kimaro et al. 2011), on ex-tin, coal, and iron mining land (Majid et al. 1994;Bhowmik et al. 1996;Munir et al. 1998;Ang and Ho 2002;Maiti 2007;Velez and Valle 2007), and various climates (Zhigang and Minquan 1987;Patil et al. 2012). Plantations of the species have typically been managed on relatively short (6 7 year) rotations (Srivastava 1993;Nurwahyudi and Tarigan 2004), with annual growth rates ranging from 20 to 45 m 3 ha 1 yr 1 (Otsamo 2001;Tham 1979). Productivity varies with site history, climate, and soil constraints (Srivastava 1993). ...
The variation in the morphological and physico-chemical properties of soils of Acacia mangium plantations were studied in South Sumatra, Indonesia in order to understand how these might affect plantation productivity. Representative soils consisting of four high productivity sites (HPS) and fi ve low productivity sites (LPS) were selected. The main difference between the two productivity classes was in subsoil morphology. HPS soils had deep pisoplinthic horizons and were classifi ed into Pisoplinthic Acrisols, LPS soils had shallow plinthic horizons and were classified into Acric Plinthosols. Differences in redox environments and water drainage in subsoil were the most likely factor creating the differences in morphology. Lower Fe o / Fe d values in HPS subsoil indicated that better drainage facilitated the dehydration and crystallization of iron oxides to convert plinthic into pisoplinthic. Productivity of Acacia plantations was correlated with subsoil characteristics. Subsoil of LPS with lower porosity and higher penetration resistance restricted deep root development, and consequently growth of Acacia, while that of HPS with higher porosity did not. The chemical characteristics of soils were also related to Acacia growth; subsoil of HPS had lower exchangeable Al, Al saturation, and higher soil pH; meanwhile T-C, T-N, T-P, available P and exchangeable cations of HPS and LPS were not signifi cant different. Site classifi cation based on subsoil characteristics, especially water drainage, and subsoil management to avoid soil compaction will be crucial for site selection and sustainable productivity of Acacia plantations.
... Due to improved industrial safeguards, certification schemes, REDD+ schemes, and needs for better corporate social responsibility, it is likely that much of the future expansion of plantations will take place in areas in need of restoration, i.e. degraded tropical lands (e.g. Otsamo, 2001). Also areas which are marginal for agriculture, or where synergies between agricultural production and tree plantations can be achieved may become more attractive for plantation expansion. ...
... In accordance with the TGHK forest classification system, forestry-based commercial activities can be implemented in Production Forests through both timber and non-timber forest product (NTFP) extraction and the development of forestry plantations. Logging concession companies (HPHs) are allowed to perform selective felling inside Limited Production Forests, while clear felling is permitted inside Permanent Production Forests (GoI/FAO, 1990;Kartodihardjo and Supriono, 2000;Otsamo, 2001). Logged-over areas left by HPHs are usually granted to HTI concessionaires for forestry industrial plantation development (Nawir et al., 2007). ...
Alternative land use remains a controversial issue in Indonesia, particularly with regard to regions outside Java. This paper aims to highlight forest land use dynamics in Indonesia, and particularly the difficulties of resolving the conflicts between conservation, the need to preserve local livelihoods, the demands of the logging industry, both legal and illegal, and the pressures to convert land from forest use to other uses, mainly agriculture, plantations and mining. The paper also stresses the importance of more research into who benefits from these competing uses of forest lands, and how these benefits have been distributed within Indonesian society. In conclusion, this paper argues that the underlying causes of deforestation in Indonesia are complex, and cover various aspects of market failure, inappropriate policy implementation in relation to forest management, lack of governance capacity at central and district levels, and other, broader socioeconomic and political issues.
... n mit kurzfristiger Nutzung als Ackerland degradieren in den Tropen viele Flächen zu Brach-oder Ödland, das beispielsweise in Indonesien oft von Alang-Alang-Gras (Imperata cylindrica) überwuchert wird. Dieses invasive Gras unterbindet eine natürliche Entwicklung der Fläche hin zu einem Sekundärwald und ist daher als besonders aggressiv einzustufen.Otsamo (2001) zitiert in seiner Arbeit mehrere Quellen, nach denen in Indonesien zwischen 8,6 Mio. Hektar (Garrity et al. 1997 in Otsamo 2001) und 64,5 Mio. Hektar (Suryatna & McIntosh 1980 in Otsamo 2001) Alang-Alang-Grasland zu finden sind. Auch Holmes (2002) geht von mehreren Millionen Hektar entsprechender Flächen aus undDros (2003) schätzt sie a ...
ABSTRACT:
Dryland ecosystems support the livelihood of millions of people in the Horn of Africa. However, these ecosystems have been exploited and affected by continuous overgrazing, fire and tree cutting. The general aim of the study was to find ways of improving the adaptive strategy and livelihood of the rural communities, and promoting ecosystem sustainability in the Horn of Africa, using Kenya and Somalia as specific case studies. The theoretical framework of the study was based on the conceptual framework for sustainable development or sustainability. The study examined the non-wood forest products (NWFPs), both for food and non-food commodities, harvested to overcome food insecurity. It paid particular attention to the role of the aromatic resin bearing species of Boswellia and Commiphora in poverty alleviation and climate change adaptation in the region. It also examined the rural communities’ views on the causes, effects and socio-economic impacts of resource degradation. Socio-economic field surveys were conducted in Wajir district of northeastern Kenya and three districts in Somalia, Addado, Buhodle and Galka’ayo. A systematic literature review was also employed to identify, select and critically review the current information on socio-economic contributions of aromatic resins in the Horn of Africa.
Quantitative analyses from surveys, group discussions and key informant consultations were used in processing the data. The research identified several woody species which provide both food and non-food products which supports the livelihood of the rural communities. The results emphasised the potential for using Boswellia and Commiphora species as agroforestry trees, for not only improving the economic conditions of the farmers, but also for increasing land productivity. The study highlighted forest degradation, droughts, building of reservoirs and over-grazing as the main factors causing land degradation in the study areas. Farmers’ adoption of new agroforestry management techniques in general, and those for Boswellia and Commiphora species in particular, has a distinct role in biodiversity conservation and climate change adaptation in the Horn of Africa. This would also enhance ecosystem sustainability and improve rural livelihood
security and thereby facilitate poverty alleviation.
Keywords: Acacia-Commiphora woodlands, agro-pastoralists, aromatic resins, Boswellia,
climate change adaptation, deforestation, desertification, food security, frankincense, Horn of
Africa, Kenya, land-degradation, livelihoods, myrrh, non-wood forest products, non-timber
forest products, pastoralists, Somalia.
Author’s address:
Badal Ahmed Hassan,
Viikki Tropical Resources Institute (VITRI),
Department of Forest Sciences,
P.O.Box 27 (Latokartanonkaari9), FI-00014
University of Helsinki, Finland.
E-mail: badal.hassan@helsinki.fi
Democracy as the government of the people by the people and for the people, equally represented is one of the most contested claims worldwide yet cherished by many and associated with a universal human right. The word “democracy” did not appear in the global participatory forest policy i.e., the shifting of global forest paradigm toward more participation in the 1970s. However, one of the core ideas of democracy, namely the right of local people to participate in the decision making over the use and management of their forest resources underpinned the policy proposal. Donors and international development agencies such as the United Nations Development Program (UNDP), the Food and Agriculture Organisation (FAO) and other large nongovernmental organizations subscribed to these principles and aimed to translate them into local contexts. Likewise, central government in sub-Sahara Africa, specifically in Burkina Faso undertook political decentralization reforms and participatory forest management programmes to implement these principles of inclusion and self-determination at the local level. It is worth mentioning that beside these discursive aspects of democratisation, the material and political economy of decentralisation and participation in sub-Sahara Africa is argued to be a measure taken to mitigate the negative effects of structural adjustment policies, increase popular legitimacy and public responsibility for growth and social welfare. However, in practice, participatory forest policy and decentralization still await an effective devolution of decision-making authority to local people and the improvement of their livelihoods. In addition, the state and non-state policy translators as above continue to choose processes, plan and implement environmental projects, often in partnerships with other than the democratically elected bodies. In doing so, they risk privatizing common resources, undermine democratization, shrink the public domain and limit citizenship and the spaces available for local people’s engagement in forest management. While literature exists on those issues, it remains unclear how these three dimensions of local democracy i.e., representation, citizenship and public domain operate under environmental interventions in the context of Burkina Faso. Therefore, I ask how participatory forest policy is translated at the local level in sub-Sahara Africa, specifically in Burkina Faso. How do the translation processes influence local democracy?
I adopted a policy translation perspective to acknowledge the turbulence of policy processes, the agency of both project implementers and local people and the unpredictability of the policy outcomes. I further used the theoretical lens of the “choice and recognition” framework to assess the democracy effects of forestry interventions namely on local peoples’ representation, citizenship and the public domain.
I investigated these three components of local democracy through the four articles included in this dissertation: The politics of representation in forest restoration in Africa (Article II); the dynamics of citizenship in forest conservation politics in Burkina Faso (Article III) and the patterns of the public domain through a gender and institutional bricolage lens (Articles IV and I), using qualitative research methods. I collected data with national and local level actors using participant-observation, semi-structured, in-depth interviews, group and focus group discussions in gendered and ethnically disaggregated groups. The recordings were transcribed and the data coded in Atlas.ti 8. I applied content and discourse analysis to interpret the results and produced basic descriptive statistics in an Excel spreadsheet.
The results showed that in Burkina Faso, global forest policy was translated at the local level through political decentralization reforms and participatory forestry projects. The choices of local institutions made by the project implementers influenced the substantive representation of local people’s interests and the effectiveness of forest restoration outcomes (Article II). The forestry interventions unintentionally produced uneven forms of citizenship, turning citizens into denizens i.e., those whose citizenships was revoked (Article III). Lastly, Articles IV and I depicted the multi-layered and complex dynamics in the public domain, continually contested by both customary and post-colonial state logics.
From the findings, it can be inferred that participatory forestry has the potential to strengthen local democracy through political decentralisation. However, the current policy translation processes based on the multiplication and recognition of parallel and competing local institutions’ representatives such as user groups can undermine democratisation, weaken substantive representation, erode the material foundations of political belonging and citizenship and reduce the effectiveness of the public domain for meaningful change.
Local realities and the actors carrying the burden of forestry interventions remain sometimes invisible in the shadows of global forest governance. A more practical approach to participatory and decentralized forest management could help mitigate the emerging issues. Further improving the lenses used to study these such as the choice and recognition framework could be a step forward in shedding light on the local processes and outcomes and advance an understanding of what hampers and enables democracy in and through global forest policy. Thus, I recommend to more systematically pay attention and integrate indicators of local democracy when trying to apply global forest policies in a local context.
Key words: local democracy, community participation, policy translation, institutional choice, citizenship, public domain, institutional bricolage, gender, restoration, forest conservation.
Study on growth of jabon (Anthocephalus cadamba Miq) as native tree species that suitable for pulpwood on ultisol-soil land is required, as most pulpwood plantation occur in this type of soil. The experiment was conducted in ex Acacia mangium (second rotation) in Riau to evaluate the growth performance of jabon on marginal land ultisol soil. This study assigned experiment plots of jabon with three planting spaces (2 m × 2 m; 2 m × 3 m and 3 m × 3 m) and four blocks in Randomized Block Design. The poor growth was exhibited by jabon on marginal land ultisol. It was suggested that the poor growth related to the negative effects of low N and P soil, high Al soil, and threats of pest, disease, weed as well. The result study indicated that jabon was not suitable to be developed as pulpwood species in marginal lands ultisol of pulpwood plantation in Riau.
Globally the area of forest plantations has increased by about 2.8 million ha (10,000 mi2) per year from 2000 to 2005. However, it is rather uncertain what the social and environmental impacts of tropical forest plantations are, especially in deforested areas. In this chapter the cases from Indonesia (industrial tree plantations), Zimbabwe (small scale woodlots), and Ghana (agroforestry in modified taungya system) are selected to provide additional information particularly on the impacts of forest plantations on people’s livelihood. The results suggest that all three types of plantations can make positive impacts on rural livelihoods. Even though they cannot provide many non-wood forest products and benefits in the same way as natural forests do, their integration into traditional local livelihoods is indeed possible, as long as sufficient areas are left out of the tree plantation scheme. In addition, the species diversity measurement from three countries suggests that in heavily deforested areas, forest plantations may even contribute to the richness of tree species and other flora.
Cogongrass [I. cylindrica (L.) Beauv.] is one of the most cosmopolitan grass species throughout the tropical and subtropical regions and is considered to be one of the 10 most troublesome and problematic weedy species in the world. It is considered a weedy pest in over 73 countries with over 100 common names associated with it, including cogongrass, japgrass, speargrass, alang-alang, and bladygrass. Cogongrass is found in every continent except Antarctica and is generally associated with areas disturbed by human activities.
A 2,500-year vegetation history was reconstructed by analyzing phytolith assemblages in sediments from Paitan Lake located in the Central Plain of Luzon, the Philippines. Five local zones of phytolith assemblage were established for the sediment sequence analyzed. Cogon (Imperata) dominated in Zone 5 (ca. 2,460–1,410 cal. yr BP), cogon and other Gramineae grasses and coniferous trees dominated in Zone 4 (ca. 1,410–1,240 cal. yr BP), non-cogon Gramineae grasses and trees dominated in Zone 3 (ca. 1,240–1,150 cal. yr BP), cogon and other Gramineae grasses and trees dominated in Zone 2 (ca. 1,150–350 cal. yr BP), and Oryza sativa (rice) increased while trees disappeared in Zone 1 (ca. 350–0 cal. yr BP). The results of this study indicate that trees were included in the component species of the vegetation at least until ca. 350 years ago, and that woodlands were replaced with rice fields and Gramineae grasslands. The development of cogon grasslands in Zone 5 may have been due to drier climatic conditions.
Understanding the carbon (C) sequestration potential of drylands requires knowledge of the stocks of C in soils and biomass and on the factors affecting them. The overall aim of the study was to determine and evaluate the variation in the C stocks and water balance of Acacia savannah woodlands across the dryland (arid and semi-arid) region (10-16 ºN; 21-36 °E) of the former Sudan (now mainly in the Republic of the Sudan) and how they are related to climatic factors and may be affected by climate change. The role played by small but numerous brick making industries on woodland deforestation in the region and greenhouse gas production was also investigated. The study region is often referred to as the gum belt because it is the world s major source of gum Arabic, which is harvested from Acacia trees. The soils in the centre and west of the region are mainly Arenosols (sandy soils) and those in the eastern part are mainly Vertisols (clay soils). The soils are C poor and often in a degraded state.
This dissertation consists of a summary section and four articles (Study I, II, III and IV). Study I focuses on fuelwood consumption by the brick making industries (BMIs) and associated deforestation and greenhouse gas (GHG) emissions. In Study II the C densities (g C m-2) of the woodland tree biomass and soil (1 m) for 39 map sheets covering the study region were determined from national forest inventory data and global soil databases and the dependence on mean annual precipitation (MAP) and mean annual temperature (MAT) determined. The water balance of savannah woodlands for the same 39 map sheets was modelled in Study III and the variation in water balance components across the region evaluated. The potential impacts of climate change on woodland biomass C density and water-use (actual evapotranspiration, AET) was analysed for eight of the map sheets in Study IV.
Sudanese BMIs consume a considerable amount of fuelwood that mainly comes from unsustainably managed woodland and contributes to deforestation and GHG emissions (Study I). While GHG emissions from BMIs only account for a small part of Sudan s total GHG emissions, the associated deforestation and land degradation is of concern. Implementation of better regulation, use of biomass fuel from sustainable sources and technological improvement in BMIs kilns will reduce deforestation and GHG emissions.
Savannah woodland C densities, both biomass and soil, were low and clearly below potential C sequestration capacity (Study II). The loss of trees across the region was indicated by very low biomass C density values in comparison to modelled NPP (net primary production) values. The estimated SOC densities although low, were higher than reported in some recent soil C studies from the region. This was attributed to the use of old data in the global soil database and indicates the degree of land degradation and loss of SOC that has taken place over the last few decades. However, in spite of woodland and soil degradation, biomass C and SOC densities remained positively and significantly correlated with each other and both were significantly correlated to MAP. The results highlighted the need for improved land-use management and stewardship, which should involve increasing the cover of trees, and the need for up-to-date regional and integrated soils and forest (woodland) inventories to be made.
Water-use (AET) of savannah woodlands is strongly limited by rainfall. Rainfall exceeded AET only during some of the wet season months resulting in a small increase in soil moisture storage and production of surface runoff for some areas (Study III). Drainage (to groundwater) was negligible. Since AET was strongly limited by MAP, AET for both Arenosol and Vertisol soil types increased southwards across the study region. Runoff also increased southwards across the study region for both soil types but were highest in south western and eastern areas. The restoration of woodlands may be expected to improve the soil-water conditions.
Compared to baseline (1961-1990) climate values, General Circulation Model (GCM) based results for 2080s indicated that MAT would increase across the study region but that MAP would either increase or decrease depending on climate change scenario (Study IV). Biomass C densities will be significantly affected by climate change. However, the impact varies with climate change scenario, with either increases or decreases in biomass C density being indicated for the same area. In general, water-use on Arenosols will increase while that on Vertisols will decrease. The largest relative changes in AET were associated with the areas receiving the lowest rainfall. Thus, even if MAP increases, the increase will have little impact on biomass levels in the driest areas of the region.
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