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ArticleThe estimation of succession index for forest cover types in the natural forest of Jirisan
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.The forest succession is changing process in the structure and function of a forest for a long period of time. The process might vary in different forest types which have undergone their own successional pathways. This study was conducted to understand the extent of successional progress by estimation of succession index for forest cover types in the natural forest of Jirisan. The vegetation data were collected by point-quarter sampling method. Five hundred sample points were subjected to cluster analysis to classify eight forest cover types. The succession index was developed through standardization of climax index and relative density of composed tree species plus species diversity index of the corresponding forest cover type. The results showed that Carpinus laxiflora cover type had the greatest succession index value of 219.7, followed by Mixed mesophytic cover type 218.3, Fraxinus mandshurica - Betula costata cover type 180.7, Quercus serrata cover type 171.3, Q. mongolica cover type 164.8 and Q. variabilis cover type 138.5. Pinus densiflora cover type had the smallest value of 101.9. It was presumed that the higher value of succession index in a certain forest cover type indicated the closer position to the climax stage in terms of sere spectrum. The author Carpinus laxiflora cover type and Mixed mesophytic cover type had made much greater succession progress toward climax than any other forest cover types. However, estimated succession index in the forest does not mean the absolute level of successional stage, but comparative assessment in the position of the seral stage among forest cover types. Based on the comparison of structural characteristics and approximation of successional pathways of classified forest cover types, it is assumed that, on the site of mid-slope and valley with loamy soils and good moisture condition in Jirisan, if no more disturbed, various forest types should make progress of succession toward the mixed mesophytic cover type. Keywords: Forest cover type; Climax index; Succession index; Jirisan ID: 3621636 -
ArticleImprovement of the forest cover-changes cartography from global forest change for critical deforestation regions in Mexico. Case of the Lacandona Region 2014-2021
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Global Forest Change (GFC) is a global monitoring system with moderate resolution (Landsat, 30 m pixel) that allows knowing the location and magnitude of the losses or gains of global forest cover. Critical Forest Change (CFC) is a calibration system based on comprehensive photo interpretation (1:10,000 scale for change editing, and 1:5,000 scale for interpretation- confirmation of change strata), with diagnostic criteria supported by field data of the National Forest Inventory (scale 1:1, period 2014-2021). CFC reduces until 85.8% the overestimation of the forest loss of GFC in the case of the Lacandona Region (327,646 ha). The process included the analysis of data at 330 study sites and the interpretation of 1,190 frames of Spot-6 (April 28, 2014) versus Sentinel-2 (April 24, 2021) in higher resolution (10 m). The annual rate of forest loss obtained by GFC (4,526 ha.yr-1) is 1.87 times higher than the LFC rate (2,415 ha.yr-1). Through a comparative analysis between the cartography of GFC and CFC, it was possible to identify that 19.2% of the differences correspond to phenological changes (leaf fall deciduous, greenness variation, or alteration of the biomass due to eventual changes in humidity). 31.3% by Landsat spatial resolution limitations, 3.8% occurs in changes by industrial plantations, 11.6% of the differences can reduce by eliminating the GFC residuals outside the forest FAO definition (changes less than 0.5 ha), 7.4% of the differences correspond to atmospheric noise in the interpreted images, 6.8% to visual omissions and 19.9% there are no changes by interpretation. The cartographic adjustment of GFC by CFC is relatively fast (1,000 ha.hr-1 per photointerpreter-expert). Its implementation improves the spatial coherence, periodicity, and legibility of the areas of change, strengthening the relevance of both systems in local policy decisions. Cartographic results of this work are available at http://selvalacandona.ecosur.ourecosystem.com Keywords: Selva Lacandona; Critical Forest Change; Global Forest Change; Forest Monitoring; Deforestation. ID: 3624121 -
ArticleAssessing land use and cover change, forest degradation and secondary forest databases for better understand of airborne CO2 measurements over the Brazilian Amazon
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Tropical forests are essential for ecosystem services provision and for climate change mitigation. Amazon forest, the largest continue tropical forests in the world, have been decreasing due to deforestation and forest degradation. Brazil, a country containing most of the Amazon forests, also presents the highest deforestation rates within the Pan-Amazonian countries. The CARBAM project has been collecting bimonthly CO2 atmospheric measurements from an airplane since 2010 in the Brazilian Amazon, showing that there is a reduction on the forest capacity to absorb carbon for deforestation and climate change patterns. To understand these CO2 fluxes, we need to analyze the land use and cover change processes including forest degradation and secondary forest growth. Our goal is to assess different databases to better understand deforestation, degradation and secondary forest dynamics in the Amazon. For this, we merged different databases for the period 2010-2018: MapBiomas for land use and cover change; PRODES for deforestation; Bullock et al. (2020) for degradation; and Silva et al. (2020) for secondary forest. We found that, from the total accumulated deforested area in 2018 (17% of the Brazilian Amazon), pasture represent 69% fallowed by secondary vegetation 21% and agriculture 8%. The annual deforested area, smaller than secondary vegetation area, is increasing since 2012. Degradation has a different area each year. The carbon uptake by secondary forest and degradation dynamics is underestimated in the national communications of greenhouse gases, and its mapping is extremely relevant to policy makers to accomplish the National Determined Contribution. The large pasture areas deserve attention because it may permit the secondary forest to increase and provide agriculture expansion areas, decreasing in this way the pressure for deforestation and degradation of primary forest and contributing to preserve biodiversity and ecosystem services of the Amazon forests. Keywords: Amazon forests, deforestation, degradation, secondary forests, CO2 emissions ID: 3623188
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