Population dynamic and management of <Emphasis Type="Italic">Pinus oocarpa</Emphasis> and <Emphasis Type="Italic">Tabebuia rosea</Emphasis> within silvopastoral systems in Central America

Silvopastoral systems—the management of trees within pastures from natural regeneration or planting—are a strategy to promote sustainable livestock systems and ecosystems services. Timber is one of the products from these systems with potential to increase family revenues. The management of natural regeneration and population dynamics of trees is a feasible way to harvest timber and maintain environmental services. In this research, we modeled the population dynamics of Pinus oocarpa and Tabebuia rosea, two important timber species of silvopastoral systems in Central America. The results showed that farmers manage a significant density of different tree species from natural regeneration. However, only the species with well-known uses or desired services are allowed to remain. The natural regeneration is more impressive in silvopastoral systems with natural grass than those with exotic grass. Farming practices, for instance use of fire for weed control, are the main reasons for low rates of natural regeneration in pastures with exotic grass. The models of population dynamics for both species showed that the sustainable timber harvest plans are a viable activity in pasturelands under natural-regeneration management plans. Innovative farmers are willing to adopt silvicultural practices and management of population dynamics to increase timber revenues and sustainability if forestry regulations for sustainable use of trees in farms are simplified.     

A Case Study Assessment of Agroforestry

Summary

Finding sustainable land-use systems within the Panama Canal Watershed will be necessary for future management by the Panamanian government. Agroforestry is a land-use option for small-scale farmers living within the Watershed that can help achieve the goals of both conservation and productivity. This case study qualitatively evaluates current agroforestry projects in the Canal Watershed using an analytical framework based on other evaluations of agroforestry systems in Central America. Designated criteria for the analysis include: management objectives, project life span, incentives, technology, economic feasibility, community involvement, and extension. These factors can present obstacles to wide-scale adoption of agroforestry systems by small-scale farmers, thus preventing the realization of associated benefits of agroforestry. The analysis of the three field sites visited in March 1998 is followed by recommendations for expanding agroforestry practices among farmers in the Watershed.     

Agroforestry in central,northern, and eastern Europe

Integrated management of natural resources and the multiple use of trees and forests have prevailed in most European societies since prehistoric times. In the Middle Ages, expanding and intensified agriculture resulted in the separation of trees from agricultural fields. During the last century, with the introduction of sustainable and highly productive forest management, the goal of increased wood production has been achieved in most parts of central, northern, and eastern Europe. Today, agroforestry is not considered to be an important land-use option within the region; however, there are many practices that could rightfully be classified as agroforestry. These include tree/crop systems in which trees provide products and/or environmental benefits, and tree/animal systems in which animals are grazed in forests or open woodlands.The future seems to offer some prospects for agroforestry. Large areas, hitherto used for food production, are either marginally suited to agriculture, or will probably be taken out of production due to agricultural policy considerations. Agroforestry may, at least in part, offer alternatives for the use of such lands. The availability of (surplus) fertile soils, capital, and labor may provide incentives for site-adapted forms of agroforestry, including improved fallow management. The focus of such systems would be on maintenance of biodiversity in the landscape, environmental protection, recreation, and product diversification.There are numerous expectations as to what agroforestry might provide for the land holder and for society as a whole. These expectations should be carefully analyzed and evaluated prior to political decisions on future land use. The promotion of agroforestry requires overall investment; agroforestry does not happen by itself. A set of integrated actions — not isolated efforts — must be implemented if agroforestry is to become a successful land-use option.     

Putting Back the Trees: Smallholder Silvicultural Enrichment of Post-Logged Concession Forest in Peruvian Amazonia

This paper presents a case of planting and management of natural regeneration of shihuahuaco (Dipteryx spp.) by recent migrants in a Peruvian Amazonian logging frontier. We interviewed residents of three communities of smallholders in Irazola District, Province of Padre Abad, Region of Ucayali, located within the historic and actual boundaries of an active logging concession, and conducted growth studies of shihuahuaco trees planted in two mixed-species agroforestry fields, over a period of 3 years. We found that the majority of landholders were managing the natural regeneration of valuable hardwood timber trees, and planting seedlings on their lands. Growth of shihuahuaco trees in agroforestry fields was comparable to growth rates in managed silvicultural plantations, which suggests the potential for local smallholders activities to contribute to conservation of genetic stock and eventual renewal of populations depleted by logging. We recommend greater recognition and inclusion of local people, with their innovative and productive silvicultural practices, in efforts to remediate the impacts of selective logging of high-value timber species.     

Financial attractiveness of smallholder tree plantations in the Amazon: bridging external expectations and local realities

This paper compares the financial attractiveness of forest and agroforestry plantations promoted by external organizations with tree growing practices of Amazonian smallholders. Based on 80 case studies and interviews with 112 forestry professionals from Brazil, Bolivia, Peru and Ecuador, the paper characterizes the economic, environmental and structural implications, and identifies the respective financial costs and benefits. Six case studies provided data for in-depth financial analyses. The results showed that the expectations of externally promoted smallholder tree and agroforestry plantations were not met. Despite significant inputs, smallholders generated at best annual net incomes of US$200–$200–1,000 per ha from NTFP plantations, and up to US$800–$800–1,000 from timber plantations in the year of harvest. This corresponded to around one-third of the initially expected returns. Overall, only around 1% of the smallholders participating in such initiatives managed to produce and commercialize any plantation products. Smallholders’ practices of complementary tree growing in conjunction with agriculture and managing natural regeneration of timber and NTFP products were often underestimated by professionals. They required low input, didn’t rely on external support, were highly flexible in risky environments, and some presented financial returns comparable to some well functioning plantations.     

Agroforestry practices of non-industrial private forest landowners in Washington State

A mail survey was conducted to gain understanding of the agroforestry practices of non-industrial private forest landowners (NIPF) in Washington State, located in the north-western USA. Although NIPF owners control 1.5 million hectares of the state's commercial forestland base, their diversity of forestland uses, land management practices and objectives as land managers are not well understood. Past NIPF surveys and anecdotal information suggest agroforestry is a major use of NIPF lands. We defined agroforestry as a potentially sustainable land use practice combining the deliberate growing of woody perennials with agricultural crops and/or animals. Objectives of this study were to:

1. determine the extent that agroforestry is used by Washington's NIPF owners,
2. develop insight into NIPF owners' motivations for practicing agroforestry,
3. describe the agroforestry practices within three distinct physiographic and agroecological zones in Washington, and
4. determine the agroforestry information needs of NIPF owners.

The target population consisted of NIPF owners in 4 counties within each of the three regions. Response to the August 1990 mail survey was 63.5%, yielding 296 useable questionnaires. Fifty-seven percent of all respondents practice agroforestry. Forestland grazing is the most common agroforestry practice (39% of all respondents), followed by windbreaks (34%), harvest of special forest products (12%), livestock enrichment plantings for forage or shelter (7%), orchard grazing (5%), orchard intercropping (2%), and Christmas tree grazing (0.34%). The most frequent motives for owning land were passing land on to children (80%), keeping it natural and income from timber (both 72%). Respondents saw aesthetics (77%), increasing land unit income (74%), and water conservation (70%) as possible advantages of practicing agroforestry. High establishment costs (66%) and livestock damage to trees or crops (64%) were the most frequently selected potential disadvantages to practicing agroforestry. Lack of technical and educational support (67%) and lack of access to livestock/livestock facilities (58%) were disincentives to practicing agroforestry. Landowners are interested in learning more about agroforestry and how agroforestry techniques might be incorporated in their land management tool kit. A significant number of non-industrial private forest land owners in Washington believe that management of forestland, balancing conservation and production goals, can be furthered by suitable agroforestry practices.     

Long-term ecological impacts of clear-fell logging on tree species diversity in a subtropical forest,southern Japan

Defining the spatial arrangement and length of the cutting cycle in a logged area is crucial for reconciling potential conflicts between timber yields and maintenance of ecosystem services in natural forests. In this study, we investigated long-term impacts of clear-fell logging on timber production and tree species diversity in a subtropical forest on the Ryukyu Islands, using an individual-based simulation model. We assumed six logging scenarios defined by combinations of forest type and regeneration processes, which acted as surrogates for spatial scales of clear-fell logging. These scenarios were simulated under cutting cycles ranging from 20 to 150 years. Short-cutting cycles resulted in dominance by the sprouting species Castanopsis sieboldii. The compositional shift was accelerated by the lack of seed dispersal from surrounding forest areas. The simulations demonstrated that a sustainable logging regime maintaining both yield and tree species diversity requires a cutting cycle longer than 50 years. The simulation results also suggest that the trade-off between the recovery of tree species diversity and timber production is favored more in stands surrounded by mature forest than in isolated stands or stands surrounded by immature forest. Ecological risk assessments based on model simulations provide an alternative to current forest management practices that rely on empirical knowledge.     

The sustainability of selection cutting in a late successional broadleaved community forest in Bhutan

This study assessed the sustainability of selection cutting in a community forest (CF) in Bhutan. The harvesting approach differed from cable crane logging operations in an adjacent commercially managed forest by creating much smaller canopy openings. This had many implications for natural regeneration of preferred species. The study was conducted in a late successional broadleaved CF containing 32 genera of tree species dominated by Quercus and Castanopsis and managed for timber, firewood, non-wood forest products and forest grazing. The study was based on a comparison of two forest inventories to assess forest structure and regeneration, a study of stumps to quantify harvesting intensities, and a household survey to quantify livestock holdings and grazing patterns. The study examined different intensities of selection cutting in three blocks of the CF and found that higher intensities of selection cutting did not have a negative impact on: (a) natural regeneration of seedlings and saplings of preferred timber species; (b) the diameter distribution of all species and use categories except for Quercus; (c) the diversity of tree genera; and (d) the percentage of remaining trees with favorable bole shape and form. These results contrasted with findings in the adjacent commercially managed forest. Community management of broadleaved forests with selection cutting appeared to be sustainable and avoid some of the unresolved silvicultural problems associated with commercially managed forests in Bhutan. However more research is needed on the sustainable management of Quercus spp.     

Indigenous market-oriented agroforestry: dissecting local diversity in western Amazonia

This paper reports on a study of local diversity and variation in indigenous agroforestry practices among Amazonian peasants in a traditional community near Iquitos, Peru. Data were gathered through in-depth interviews with agroforestry-reliant households n = 36) on farming practices, demographic characteristics, income-expenditures and household wealth. Visits to crop fields and forest fallows n = 329) allowed the reconstruction of extensive cropping histories. More in-depth assessments of crop occurrence, density and diversity were conducted on 83 fields. Our results indicate considerable variation in field characteristics, agroforestry-cycles, and household agroforestry portfolios. Agroforestry practice is found to be strongly related to access to land within the community: households holding more land use both potentially more sustainable and more lucrative swidden-fallow agroforestry systems. Our results question the view of indigenous agroforestry systems as intrinsically ‘stable, equitable, and sustainable’, and underscore the importance of studying local variation in indigenous agroforestry practices. Promising avenues are discussed for future research on the factors related to the successful adoption of sustainable agroforestry systems. This revised version was published online in June 2006 with corrections to the Cover Date.     

Man-made dipterocarp forest in Sumatra

Traditional plantations of Shorea javanica in Southern Sumatra deserve mention on three main points: (1) it is a rare case in Indonesia of successful cultivation of an indigenous species. This species being a Dipterocarp is an even more attractive reason: Dipterocarps are in the paradoxical situation of being the largest family of timber trees in natural forests of tropical Asia but are almost never used for silvicultural purposes; (2) the tree is grown in association with many other useful trees to constitute an agroforestry system of both cash and subsistence incomes; and (3) such plantations represent a good potential for the production of natural resin in the humid tropics.This paper is a slightly revised version of an internal report prepared for BIOTROP (SEAMEO — ASEAN Center for Tropical Biology). The project has been funded by BIOTROP, while the author is a French consultant to that organization.     

Conservation and restoration of degraded ecosystems in arid and semi-arid areas of northwest China

In “West Development” of China, one of the most important activities is the Natural Forest Protection Program, designed to swiftly convert the focus of management and utilization of the natural forests from a timber orientation towards forest conservation, sustainable management and environmental protection. The project covered almost all the arid and semi-arid regions in Northwest region. Accompanying this great campaign this paper studied the conservation and restoration model of degraded ecosystems in arid and semi-arid lands in Northwest China. The past practices have resulted in considerably natural forest degradation and loss through land conversion (primarily for agriculture), over-harvesting, inadequate reforestation and lack of protection. The consequences have been the loss of soil and water resources, diminished timber production capacity on a sustainable basis, and environmental losses. This paper applied Aronson’s restoration model and proposed the conservation, restoration, re-allocation and preservation program for the implementation of environmental improvement and natural forest conservation.     

Environmental influences on post-harvest natural regeneration of <Emphasis Type="Italic">Pinus pinaster</Emphasis> Ait. in Mediterranean forest stands submitted to the seed-tree selection method

Research on natural regeneration is crucial for the development of sustainable forestry practices, in light of the global climate changes taking place. In this study, 151 plots were sampled in six Pinus pinaster stands that were naturally regenerated by the seed-tree method in Mediterranean forests in central Spain. The objectives of the survey were to study the suitability of different forest stands designated for natural regeneration as well as to analyse seedling establishment and the relationship between regeneration and different site factors. Analysis of variance and multivariate analysis with canonical ordination techniques were employed. Full and partial redundancy analyses on a correlation matrix were used to carry out a direct gradient analysis of regeneration density as a function of site factors. Nearly all stands presented seedling densities over 2,000 seedlings ha⁻¹ and were thus found to be suitable for natural regeneration of Pinus pinaster by the seed-tree selection method. Significant variables that best explained total seedling and viable seedling density were spring and autumn precipitation of the year prior to establishment, spring and summer precipitation of the year of establishment and percentage cover of litter. There were no signs of competition between shrubs and seedlings, but a negative significant correlation with grass cover was observed. Pinus pinaster natural regeneration was successful with the seed-tree method, although it appeared to be highly dependent on climate and stand conditions.     

人工林和天然林的比较评价

对人工林和天然林的生态学和林学特性进行了比较和分析。指出天然林对病虫害的抵抗能力强,能持久地生产木材和发挥多重效益,并与很多物种的生存有密切关系。因人工林多样性低,稳定性差,轮伐期短,集约栽培的工业人工林尽管速生,但对地力消耗大,若没有优越的土地条件和额外的施肥,生产力将不能持久。提出我国应实行人工林和天然林并重的方针,要对大量发展工业人工林可能产生的隐患给予重视,要对已保存不多的原始林实行不改变林相的经营方式,避免将它们大面积地改变为人工林的作法。     

Forests,people and environment: some African perspectives§

Forests in Africa support the livelihoods of millions of people through provision of timber and non-timber forest products, food and nutrition, energy and payment of environmental services. However, mismanagement of forests has resulted in deforestation and forest degradation, thereby contributing to the increased emission of carbon dioxide into the atmosphere. This special issue highlights some of the research outcomes presented at a pre-congress workshop organised by the African Forest Forum and partners at the 2015 World Forestry Congress. In this issue, the main drivers of land degradation are highlighted vis-à-vis population growth, agricultural expansion, climate variability, drought and energy needs. Promising traditional management practices are identified including age-old farmer-managed natural regeneration and exclosures. In addition, research presented indicates that age-old systems such as native non-browse shrubs in Ethiopia are important in that they facilitate regeneration of late-successional tree species. Furthermore, opportunities for using forests to mitigate climate change are highlighted with a case study on the economics associated with carbon markets. The issue also highlights the methodological challenges of quantifying carbon in African forests. The effect of climate change on threatened forest species and biodiversity in general is discussed, and the associated human disturbances impacting on the population structure of a threatened species, e.g. Afzelia africana in West Africa, is presented. The important role of non-timber forest products in income generation for the rural communities and the associated challenges of commercialisation is emphasised with examples from two important tree species: shea (Vitellaria paradoxa) and baobab (Adansonia digitata). Finally, the issue covers a people-centred approach in tree planting and management where studies demonstrated that there are still problems of poor participation of local communities due to poor implementation of enabling policies, lack of involvement in initial planning and subsequent lack of clear benefit-sharing mechanisms.     

Participatory agroforestry development for restoring degraded sloping land in DPR Korea

Participatory approaches in agroforestry combine land, labor, and knowledge, by blending local experience with external expert support for sloping land restoration. We describe and analyze over a decade of bottom-up agroforestry development processes that today are influencing national policies. In the 1990s, after economic upheaval following the collapse of trade with the USSR (Soviet Union) rapid conversion of sloping lands to agriculture, in association with heavy rainfall events, caused widespread erosion and landslides. In response, pilot scale ??user groups?? obtained rights-to-use, rights-to-harvest and rights-to-plan or access to sloping lands for tree products and food. All three rights were novel in the DPR Korea and jointly contributed to success, together with active research support. Innovations in double-cropping annual food crops together with non-competitive contour strips of valuable fruits (aronia berry: Aronia melanocarpa) and/or high-value timber (larch: Larix leptolepis) emerged as preferred local agroforestry systems. Broad support for agroforestry practices has now emerged within the Ministry of Land and Environmental Protection as well as a number of universities and research centres. Further development will require increased engagement with agricultural and horticultural agencies, while the social dimensions of participatory agroforestry continue to provide rich learning.     

The importance of agroforestry hay and walnut production in the walnut-fruit forests of southern Kyrgyzstan

Walnut-fruit forests (WFF) in Kyrgyzstan are biodiversity hotspots, provide important ecosystem services, and are of economic value yet currently suffer from a lack of sustainable management. We analysed current agroforestry practices through a series of interviews with farmers and reviewed the input–output data for 5 years of hay and walnut production for three case studies. The interviews showed that hay-making and walnut collection are the primary agroforestry practices in the WFF and have clear economic importance. Walnut in particular is a source of additional income for farmers and hay-making activities are strongly influenced by the need to winter cattle in these regions. The low reliability of interview data limited the planned analysis of profitability of case studies. Walnut production, however, is difficult to calculate because it is highly dependent on weather conditions and cropping practices between walnut trees (Juglans regia L.). This study highlights the need for improved agroforestry technologies in the WFF and identifies potential means for a sustainable, multi-purpose management of the WFF with a special focus on income generation.     

Farm-forestry in the Peruvian Amazon and the feasibility of its regulation through forest policy reform

In 2015 the Peruvian government launched a new set of regulations associated with the forest law aimed to increase competiveness of the timber sector, ensure the conservation and sustainable production of timber on public and private forestlands, and improve rural livelihoods. Small-scale timber producers have been marginalized in the sector in the past, and the new regulations claim to provide pathways to formalization for these actors. We draw on policy analysis and field research in the central Amazon region of Peru using mixed methods to characterize smallholder on-farm timber production and evaluate the feasibility of the new regulatory mechanisms for formalizing small-scale timber producers. Through examining a case study on the production and sale of the fast-growing pioneer timber species Guazuma crinita, locally known as bolaina, we found a diversity of management practices, with the strongest reliance on natural regeneration in agricultural fallows, an informal supply chain, and no case of formal documentation at time of sale. We assessed that none of the new regulatory mechanisms will accommodate the sale of timber produced in agricultural fallow stands. We recommend the inclusion of fallow timber in the new forest plantation registry, which could result in the formalization of the supply chain and create an incentive to increase production by small-scale producers.     

Timber management with variable retention in Nothofagus pumilio forests of Southern Patagonia

Forestry practices integrating ecological and social criteria have been replacing those based only on economic values. Traditional silviculture, such as shelterwood cuts (SC), transforms uneven-aged original stands to an even-aged managed forest. Recently, other methods have proposed to conserve some of the original heterogeneity of the old-growth forests. One proposal leaves 30% of the timber quality forest area as aggregated retention and 20% basal area as dispersed retention. The aim of this study was to analyze the feasibility of timber management with aggregated and dispersed retention in Nothofagus pumilio old-growth forests by analyzing timber and harvesting yield potential compared with traditional regeneration systems. Also, remnant tree stability of aggregated retention was analyzed.     

Tree Culture of Smallholder Farmers Practicing Agroforestry in Gunung Salak Valley,West Java,Indonesia

This paper investigates the types of agroforestry system that exist in Gunung Salak Valley, West Java, Indonesia in order to characterize the differences in their basic structure and associated crop plant diversity. Data were collected through rapid rural appraisal, field observation and focus groups, followed by household survey of a sample of 20 agroforestry farmers. Five main agroforestry systems (homegardens, fruit tree system, timber tree system, mixed fruit–timber system, and cropping in the forest understory) exist in the study area, and all of them exhibit a noticeable diversity in terms of both species composition and utilization. Products from farming accounted for an average 24 % of household income. They comprised agroforestry products which contributed IDR 3.25 million/year and other agricultural products contributing IDR 1.66 million/year. The observed agroforestry systems include not only a form of forest dominated by ‘cultivated trees’, but also an anthropogenic vegetation formation derived from agricultural antecedents. In land-use classifications agroforestry systems are not recognized as forestry, but like forests they provide tree products and services. Classification will always be disfunctional if a binary system is applied, thus a more sophisticated approach should be adopted that incorporates the economic and environmental characteristics of a wider range of systems.     

Frugivory by five bird species in agroforest home gardens of Pontal do Paranapanema,Brazil

The inefficiency of conservation efforts based exclusively on natural habitat patches has called the attention of some conservationists to the matrix. Described as the major component of a landscape, the matrix is often agricultural, particularly in the tropics. In this context, agroforestry practices have been recognized for their ability to support a rich fauna and flora. Besides the extensive literature concerning bird communities in agroforestry systems, very few studies analyze how different species respond to the management of such practices. Our study describes the diet and habitat use frequency of five frugivorous bird species in agroforest home gardens, secondary forests, and pastures in the region of Pontal do Paranapanema, Brazil. The focal species were Ramphastos toco (Toco Toucan), Pteroglossus castanotis (Chestnut-eared Aracari), Amazona aestiva (Blue-fronted Amazon), Ara chloroptera (Green-winged Macaw), and Cyanocorax chrysops (Plush-crested Jay). We gathered both habitat use frequency and diet using the “feeding-bout” method. Overall frequency was higher in the secondary forest when compared to pasture and home gardens for all bird species except A. aestiva. The number of feeding bouts was higher in home gardens than in forests for all species with the exception of C. chrysops. Differences in monthly median feeding activity were only statistically significant for C. chrysops and for A. aestiva. The latter was the only species observed feeding in pasture habitats. The total number of food taxa was larger in home gardens than in the forest. Our results reinforce the importance of agroforestry systems as a resource-rich habitat for frugivorous birds.