Mapping the Extents of Agroforestry using Geo-informatics Agroforestry is a collective name for land-use systems and practices in which woody perennials are deliberately integrated with crops and/or animals on the same land-management unit. The integration can be either in a spatial mixture or in a temporal sequence. There are normally both ecological and economic interactions between the woody and non-woody components in agroforestry. In recent years, there has been a shift in the focus of agroforestry research from the plot or field scale to the landscape scale, which has uncovered the multiple benefits that trees provide in agricultural landscapes. But the spatial distribution and extent of agroforestry was not well understood earlier due to the complexity involved in accurately mapping agroforestry and Trees Outside Forest (TOF) in mixed tree/crop/ livestock systems. As per ISFR 2019, all trees growing outside recorded forest areas irrespective of patch size are referred as Trees Outside Forest. A major problem in estimating the area under agroforestry is the lack of procedures for delineating the area influenced by trees in a mixed stand of trees and crops. Besides, simultaneous agroforestry where the tree and the crop components grow at the same time and in close enough proximity for interactions to occur is more complex. As in simultaneous systems, the entire area occupied by multistrata systems such as home gardens, shaded perennial systems and intensive treeintercropping situations can be listed as agroforestry. The problem is more difficult in the case of practices such as windbreaks and boundary planting where trees are planted at a wide distance between rows (windbreak) or around agricultural fields (boundary planting). In such cases, the influence of trees extends over a larger area than is easily perceivable. In addition, there is a general lack of systematically collected ground reference information for the development of predictive models for the extent of agroforestry area, as well as for the validation of these estimates.
Tag: biomass
Woody Plant Species Composition, Population Structure and Carbon Sequestration Potential of the A. senegal (L.) Willd Woodland Along a Distance Gradient in North-Western Tigray, Ethiopia
In Ethiopia, dry land vegetation including the fairly intact lowland and western escarpment woodlands occupy the largest vegetation resource of the country. These forests play a central role in environmental regulation and socio-economic assets, yet they received less scientific attention than the moist forests. This study evaluated the woody plant species composition, population structure and carbon sequestration potential of the A. senegal woodland across three distance gradients from the settlements. A total of 45 sample quadrants were laid along a systematically established nine parallel transect lines to collect vegetation and soil data across distance gradients from settlement. Mature tree dry biomass with DBH>2.5 cm was estimated using allometric equations. A total of 41 woody plant species that belong to 20 families were recorded and A. senegal was the dominant species with 56.4 IVI value. Woody plant species diversity, density and richness were significantly higher in the distant plots compared to the nearest plots to settlement (p<0.05). The cumulative DBH class distribution of all individuals had showed an interrupted inverted J-shape population pattern. There were 19 species without seedlings, 15 species without saplings and 14 species without both seedlings and saplings. A significant above ground carbon (5.3 to 12.7 ton ha-1), root carbon (1.6 to 3.6 ton ha-1), soil organic carbon (35.6 to 44.5 ton ha-1), total carbon stock (42.5 to 60.7 ton ha-1) and total carbon dioxide equivalent (157.7 to 222.8 ton ha-1) was observed consistently with an increasing of distance from settlement (p<0.05). Distance from settlement had significant and positive correlation with species diversity and carbon stock at 0.64⁎⁎ and 0.78⁎⁎. Disturbance intensity may directly influence the variation of species composition, richness and density along the A. senegal woodland. The sustainability of the A. senegal woodland needs urgent protection, conservation and restoration.
Using local capacity to assess carbon stocks in two community forest in South-East Cameroon
Quantification of forest biomass is a challenge for developing countries due to insufficient data and lack of expertise. Involving villagers in this work, especially in the case of local forests could improve the speed and efficiency of this quantification process. This article describes the participatory approach implemented to assess carbon stocks in two community forests located in south-eastern Cameroon. This was put into practice for forest inventory work and the estimation of biomass and carbon stocks. The aim was to use classic scientific approaches of inventory and cartography, but involving local populations in the different stages of the process. The involvement of local populations, through the mobilization of their indigenous knowledge, significantly increases data quality and considerably reduces the costs and duration of the evaluation process. Ultimately, only 2% of the trees inventoried were “unknown” by local botanists, 92.3% of the species identified by them had accurate scientific correspondences. Help of local actors contributed to halving the time required to set up the plots and reduced the cost of operations by twenty times compared with using experts. REDD +, at least its local level monitoring dimension, could be successful if implemented in a dialectic involving expert scientists and local populations.
Asynchronous carbon sink saturation in African and Amazonian tropical forests
Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions. Climate-driven vegetation models typically predict that this tropical forest ‘carbon sink’ will continue for decades. Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53–0.79), in contrast to the long-term decline in Amazonian forests. Therefore the carbon sink responses of Earth’s two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature. Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth’s intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth’s climate.
Traits controlling shade tolerance in tropical montane trees
Tropical canopies are complex, with multiple canopy layers and pronounced gap dynamics contributing to their high species diversity and productivity. An important reason for this complexity is the large variation in shade tolerance among different tree species. At present, we lack a clear understanding of which plant traits control this variation, e.g., regarding the relative contributions of whole-plant versus leaf traits or structural versus physiological traits. We investigated a broad range of traits in six tropical montane rainforest tree species with different degrees of shade tolerance, grown under three different radiation regimes (under the open sky or beneath sparse or dense canopies). The two distinct shade-tolerant species had higher fractional biomass in leaves and branches while shade-intolerant species invested more into stems, and these differences were greater under low radiation. Leaf respiration and photosynthetic light compensation point did not vary with species shade tolerance, regardless of radiation regime. Leaf temperatures in open plots were markedly higher in shade-tolerant species due to their low transpiration rates and large leaf sizes. Our results suggest that interspecific variation in shade tolerance of tropical montane trees is controlled by species differences in whole-plant biomass allocation strategy rather than by difference in physiological leaf traits determining leaf carbon balance at low radiation. © 2019 The Author(s) 2019. Published by Oxford University Press.
Analysis of Tieghemella heckelii x Theobroma cacao L. Interaction in Traditional Agroforestry Systems in Western Cote d'Ivoire
Agromorphological and productivity parameters and incomes of cocoa companion trees assessment was studied to identify the ecological interaction between Tieghemella heckelii (makoré) and cocoa (Theobroma cacao) trees in Cote d’Ivoire. To this end studies have been carried out in rural areas in the locations of Duekoué and Taï. This work was conducted on the cocoa trees around the makoré trees over three distances around the tree (10, 20, and 30 m). Several parameters related to morphology, productivity, biomass, and CO2 stock were determined, for the two speculations. Results indicated that the trees of makoré used have the same characteristics (size, DBH, biomass, and CO2 stock). However, a difference in the shape of the fruit and/or the seed (weight of the fruit, length, and width of the seeds) and the number of seeds contained in the fruits was observed, thus reflecting a variability of individuals. Moreover, the density and yield of cocoa trees increased with distance. Indeed, cocoa trees located 30 m from the makoré trees recorded the highest rates of healthy pods. The rate of rotten and gnawed pods was similar for all distances considered, and cocoa trees located 20 m from the makoré trees were the most vigorous. Additionally, the biomass and the CO2 stock were high for large diameter and tall cocoa trees, especially the cocoa trees located 20 and 30 m from the makoré trees.
Mapping degraded lands in Indonesia for bioenergy production potential
This study conducted a spatial analysis in Indonesia to estimate degraded lands potentially suitable for growing biodiesel species (Calophyllum inophyllum, Pongamia pinnata and Reutealis trisperma) and biomass species (Calliandra calothyrsus and Gliricidia sepium). Degraded lands have limited functions for food production, carbon storage, and conservation of biodiversity and native vegetation. Thus, identifying their potential to produce bioenergy can contribute to sustainable development by helping society to meet increasing energy demands and secure a new renewable energy source. The identified potential degraded lands were further examined with two scenarios: 1) an all-five-species scenario, examining the growth of all five species, and 2) a biodiesel-species-only scenario, analysing the growth of only biodiesel species. Study results illustrated approximately 3.5 million ha of degraded lands potentially suitable for these species in Indonesia. The all-five-species scenario indicated that these lands had the potential to produce 1,105 PJ yr¯¹ of biomass and 3 PJ yr¯¹ of biodiesel. The biodiesel-species-only scenario illustrated that these lands had the potential to produce 10 PJ yr¯¹ of biodiesel. In addition, many of these degraded lands were limited to support economies of scale for biofuel production due to their small land sizes. The study findings contribute to identifying lands with limited functions, modelling the growth of biofuel species on regional lands, and estimating carbon stocks of restored degraded lands in Indonesia.
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Exploring characteristics of national forest inventories for integration with global space-based forest biomass data
National forest inventories (NFIs) are a reliable source for national forest measurements. However, they are usually not developed for linking with remotely sensed (RS) biomass information. There are increasing needs and opportunities to facilitate this link towards better global and national biomass estimation. Thus, it is important to study and understand NFI characteristics relating to their integration with space-based products; in particular for the tropics where NFIs are quite recent, less frequent, and partially incomplete in several countries. Here, we (1) assessed NFIs in terms of their availability, temporal distribution, and extent in 236 countries from FAO’s Global Forest Resources Assessment (FRA) 2020; (2) compared national forest biomass estimates in 2018 from FRA and global space-based Climate Change Initiative (CCI) product in 182 countries considering NFI availability and temporality; and (3) analyzed the latest NFI design characteristics in 46 tropical countries relating to their potential integration with space-based biomass datasets. We observed significant NFI availability globally and multiple NFIs were mostly found in temperate and boreal countries while most of the single NFI countries (94 %) were in the tropics. The latest NFIs were more recent in the tropics and many countries (35) implemented NFIs from 2016 onwards. The increasing availability and update of NFIs create new opportunities for integration with space-based data at the national level. This is supported by the agreement we found between country biomass estimates 2018 from FRA and CCI product, with a significantly higher correlation in countries with recent NFIs. We observed that NFI designs varied greatly in tropical countries. For example, the size of the plots ranged from 0.01 to 1 ha and more than three-quarters of the countries had smaller plots of ≤0.25 ha. The existing NFI designs could pose specific challenges for statistical integration with RS data in the tropics. Future NFI and space-based efforts should aim towards a more integrated approach taking advantage of both data streams to improve national estimates and help future data harmonization efforts. Regular NFI efforts can be expanded with the inclusion of some super-site plots to enhance data integration with currently available space-based applications. Issues related to cost implications versus improvements in the accuracy, timeliness, and sustainability of national forest biomass estimation should be further explored.
Water consumption of industrial hemp (Cannabis sativa L.) from a site in northern Kazakhstan
Purpose: This study investigated the water consumption (crop evapotranspiration) of industrial hemp on a newly established hemp field in Aqmola Region of Northern Kazakhstan. Methodology: The water consumption of hemp was investigated through direct measurements of the sapflow movement during the second half of the growing season 2021. These sapflow data yielded data on the water consumption. The water consumption of the first part of the growing season was assessed through the Penman-Monteith approach by FAO. Findings: The water consumption of hemp was 353 mm over the growing season at a stem yield of 10 t/ha. Under the water supply conditions of the study site, hemp offers higher yields than grasslands or grains. Originality/value: This is the first study that revealed data on water consumption of hemp for the region Central Asia as a potential
The global cropland footprint of the non-food bioeconomy
A rapidly growing share of global agricultural areas is devoted to the production of biomass for non-food purposes. The derived products include, for example, biofuels, textiles, detergents or cosmetics. Given the far-reaching global implications of an expanding nonfood bioeconomy, an assessment of the bioeconomy’s resource use from a footprint perspective is urgently needed. We determine the global cropland footprint of non-food products with a hybrid land flow accounting model combining data from the Food and Agriculture Organization and the multi-regional input-output model EXIOBASE. The globally interlinked model covers all cropland areas used for the production of crop- and animal-based non-food commodities for the years from 1995 to 2010. We analyse global patterns ofraw material producers, processers and consumers of bio-based non-food products, with a particular focus on the European Union. Results illustrate that the EU is a major processer and the number one consumer region of non-food cropland, despite being only the fifth largest producing region. Two thirds of the cropland required to satisfy EU non-food consumption are located in other world regions, giving rise to a significant dependency on imported products and to potential impacts on distant ecosystems. With almost 29% in 2010, oilseed production, used to produce, for example, biofuels, detergents and polymers, represents the dominant share in the EU’s non-food cropland footprint. There is also a significant contribution of more traditional non-food biomass uses such as fibre crops (for textiles) and animal hides and skins (for leather products). Our study emphasises the importance of comprehensively assessing the implications of the non-food bioeconomy expansion as envisaged in various policy strategies, such as the Bioeconomy Strategy of the European Commission.