Acacias are of considerable social and industrial importance for tropical reforestation, with about 2 million ha worldwide. The last few decades have seen a major expansion of plantations for industrial use, especially in South-East Asia. Both native and exotic species of Acacia are also widely grown in the Indian sub-continent. Turnbull et al. (1998) reviewed the status of tropical acacia plantations in Asia. The species which have been most widely planted so far in industrial plantations in South-East Asia are Acacia mangium Willd. and A. auriculiformis Cunn. ex Benth. A. crassicarpa Cunn. ex Benth. and A. aulacocarpa Cunn. ex Benth. provenance and species trials have been established in many locations throughout the region to provide options for future hardwood plantations. Commercial plantings of A. crassicarpa have recently been established in Indonesia. Plantations of acacias in the humid tropics have been relatively free of disease compared to eucalypts that are commonly damaged by disease in such environments. Reports from several countries in South-East Asia and northern Australia have, however, suggested that the future productivity of acacia plantations may be affected by fungal pathogens. During 1995–96, surveys of diseases of the four Acacia species mentioned above were carried out in northern Australia and several countries of South-East Asia, supported by funding from the Australian Centre for International Agricultural Research (ACIAR) and the Center for International Forestry Research (CIFOR). The surveys by forest pathologists were undertaken in native stands, trials and industrial and social forestry plantations of tropical acacias in Australia, India, Indonesia, Malaysia and Thailand. The objectives were to assess the potential of fungal pathogens as limiting factors to tree growth and productivity, and to compare the relative importance of individual fungal pathogens.
Tag: forest plantations
Enhancing Accuracy in Historical Forest Vegetation Mapping in Yunnan with Phenological Features, and Climatic and Elevation Variables
Human activities have both positive and negative impacts on forests, altering the extent and composition of various forest vegetation types, and increasing uncertainty in ecological management. A detailed understanding of the historical distribution of forest vegetation is crucial for local conservation efforts. In this study, we integrated phenological features with climatic and terrain variables to enhance the mapping accuracy of forest vegetation in Yunnan. We mapped the historical distributions of five forest vegetation type groups and nine specific forest vegetation types for 2001, 2010, and 2020. Our findings revealed that: (1) rubber plantations can be effectively distinguished from other forest vegetation using phenological features, coniferous forests and broad-leaved forests can be differentiated using visible spectral bands, and environmental variables (temperature, precipitation, and elevation) are effective in differentiating forest vegetation types under varying climate conditions; (2) the overall accuracy and kappa coefficient increased by 14.845% and 20.432%, respectively, when climatic variables were combined with phenological features, and by 13.613% and 18.902%, respectively, when elevation was combined with phenological features, compared to using phenological features alone; (3) forest cover in Yunnan increased by 2.069 × 104 km2 (10.369%) between 2001 and 2020. This study highlights the critical role of environmental variables in improving the mapping accuracy of forest vegetation in mountainous regions.
Improved Coffee Management by Farmers in State Forest Plantations in Indonesia: An Experimental Platform
The Indonesian state forest managers have accepted farmer-managed coffee agroforestry in their estates as part of their social forestry program. Access by local farming communities to state-owned plantation forestry supports public motivation to maintain forest cover. However, balancing the expectations and needs of forest managers with those of the local farming communities is not easy. Coffee yields in Indonesia are lower than those of neighboring countries, suggesting that there is scope for improvement. Here we describe an experimental research platform developed through an international collaboration between the Universitas Brawijaya (UB), the UK Centre for Ecology and Hydrology (UKCEH), and smallholder coffee farmers to explore options for improving pine-coffee agroforestry systems within existing regulations. Located in a former state-owned pine production forest on the slopes of the stratovolcano, Mount Arjuna, in the Malang Regency of East Java, the research platform has seven instrumented research plots (40 × 60 m2), where agronomic practices can be trialed. The aim of the platform is to support the development of sustainable agronomic practices to improve the profitability of coffee agroforestry and thus the livelihood of low-income rural communities. Current trials are focused on improving coffee yields and include pine canopy trimming, fertilizers, and coffee pruning trials, with links to the development of socio-economic and environmental models. Whilst it is too early to assess the full impacts on yields, a survey of farmers demonstrated a positive attitude to canopy pruning, although with some concern over labor cost. The initial ecosystem modelling has highlighted the benefits of coffee agroforestry in balancing environmental and economic benefits. Here we provide a detailed description of the site, the current trials, and the modelling work, with the hope of highlighting opportunities for future collaboration and innovation.
Giant milkweed (Calotropis gigantea): A new plant resource to inhibit protozoa and decrease ammoniagenesis of rumen microbiota in vitro without impairing fermentation
This study screened six different species of forest plants and then further evaluated the most promising plant, giant milkweed (Calotropis gigantea), for the potential to improve nitrogen utilization efficiency (NUE) through inhibiting rumen protozoa in vitro. Ground leaves of giant milkweed at 1.6 and 3.2 mg/mL decreased the counts of Entodinium cells by 41.30% and 58.89%, respectively, and damaged their cell surface structure. Dasytricha, Isotricha, Epidinium, Ophryoscolex, and Diplodinium were not affected, while total bacterial and archaeal populations did not decrease. Ammonia nitrogen (NH3-N) concentration decreased by 50.64% and 33.33% at 1.6 g/mL and 3.2 mg/mL, respectively. Volatile fatty acid (VFA) production and methane production remained unaffected, but butyrate production increased. The giant milkweed leaves contained (per gram of dry matter) 3636 μg phenolics including 205.9 μg of 3-hydroxybenzoic acid, 2079 μg flavonoids including 1197.5 μg of quercetin and 91.4 μg of myricetin, and 490 μg alkaloids including 219.8 μg of anthraquinone glycosides. The effective inhibition of Entodinium was accompanied by a decrease in NH3-N concentration, and methane production did not increase except for the dose of 1.6 mg/mL. Giant milkweed may be used as a new feed additive or an alternative to chemicals or antibiotics for sustainable animal husbandry enhancing NUE in ruminants.
The socioeconomic impacts of large-scale tree plantations on local communities: A systematic review protocol
Background. To meet increasing demand for forest products and services, the global area of planted forests has increased dramatically over the past 25 years. Further increases in large-scale tree plantations are expected due to their high productivity, economic profitability and contribution to climate change mitigation targets. This raises questions about their long-term sustainability, as well as their impacts on forest ecosystem services and local livelihoods, particularly in countries characterized by rural poverty and insecure property rights. Previous studies have revealed mixed impacts, but there is a lack of research on the contexts and practices that can contribute to positive and/or negative socioeconomic impacts. This protocol provides guidelines for a systematic review that synthesizes the current literature on the direct and indirect impacts of large-scale plantations on local communities, and which will also identify trends, bias and gaps in the empirical evidence base.
Methods. The primary research question of the systematic review asks “What are the direct and indirect socioeconomic impacts of large-scale tree plantations on local human populations?” We apply a Population-Exposure-Comparator-Outcome-Context (PECOC) framework to structure each stage of the systematic review, which comprises a comprehensive literature search, screening, quality assessment, data extraction and analysis.We define the exposure of interest to be the establishment or management of a large-scale tree plantation by external actors, population of interest as households and communities living in close proximity to plantation sites, comparators as other communities who have not experienced the same exposure as well as the same communities prior to plantation establishment, outcomes as the direct or indirect socioeconomic impacts felt by the population as a result of plantation establishment, and context as the social, political and environmental factors that may have led to differences in experienced impacts. We will search multiple bibliographic databases and organizational websites for relevant studies in both the published and grey literatures. These results will be screened by their titles and abstracts followed by their full texts based on predetermined eligibility criteria. To ensure that selected studies have controlled for potential biases, quality assessment will then take place alongside data extraction. Finally, the results of quantitative and qualitative analyses will be reported in a narrative synthesis.