scholarly journals New Fusion Algorithm for Improving Secondary Forest Cover Mapping

2020 ◽  
Vol 9 (1) ◽  
pp. 3251-3263
Author(s):  
Jwan Aldoski ◽  
◽  
Shattri B. Mansor ◽  
Zailani Khuzaimah ◽  
◽  
...  
1996 ◽  
pp. 51-54 ◽  
Author(s):  
N. V. M. Unni

The recognition of versatile importance of vegetation for the human life resulted in the emergence of vegetation science and many its applications in the modern world. Hence a vegetation map should be versatile enough to provide the basis for these applications. Thus, a vegetation map should contain not only information on vegetation types and their derivatives but also the geospheric and climatic background. While the geospheric information could be obtained, mapped and generalized directly using satellite remote sensing, a computerized Geographic Information System can integrate it with meaningful vegetation information classes for large areas. Such aft approach was developed with respect to mapping forest vegetation in India at. 1 : 100 000 (1983) and is in progress now (forest cover mapping at 1 : 250 000). Several review works reporting the experimental and operational use of satellite remote sensing data in India were published in the last years (Unni, 1991, 1992, 1994).


Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 817
Author(s):  
Marina Palmero-Iniesta ◽  
Josep Maria Espelta ◽  
Mario Padial-Iglesias ◽  
Òscar Gonzàlez-Guerrero ◽  
Lluís Pesquer ◽  
...  

Farmland abandonment has been a widespread land-use change in the Iberian Peninsula since the second half of the 20th century, leading to the establishment of secondary forests across the region. In this study, we aimed to address changes in the recent (1985–2014) emergence patterns of these forests and examine how environmental factors affected their growth by considering differences in leaf-habit types. We used a combination of Landsat-derived land-cover maps and aboveground biomass (AGB) maps from the European Space Agency to assess the secondary forest establishment and growth, respectively, in the study region. We also obtained a set of topographic, climatic and landscape variables from diverse GIS layers and used them for determining changes over time in the environmental drivers of forest establishment and AGB using general linear models. The results highlight that secondary forest cover was still increasing in the Iberian Peninsula at a rate above the European average. Yet, they also indicate a directional change in the emergence of secondary forests towards lower and less steep regions with higher water availability (mean rainfall and SPEI) and less forest cover but are subjected to greater drought events. In addition, these environmental factors differentially affect the growth of forests with different leaf-habit types: i.e., needleleaf secondary forests being less favoured by high temperature and precipitation, and broadleaf deciduous forests being most negatively affected by drought. Finally, these spatial patterns of forest emergence and the contrasting responses of forest leaf-habits to environmental factors explained the major development of broadleaf evergreen compared to broadleaf deciduous forests and, especially, needleleaf secondary forests. These results will improve the knowledge of forest dynamics that have occurred in the Iberian Peninsula in recent decades and provide an essential tool for understanding the potential effects of climate warming on secondary forest growth.


2002 ◽  
Vol 46 (1) ◽  
Author(s):  
Dietrich Schmidt-Vogt

AbstractManagement of secondary tropical forests: a new perspective for sustainable use of forests in Asia. The decline of primary forests in the tropics is leading to a reassessment of the role secondary forests might play within the context of tropical forest management. Recent research has shown that secondary forests in the tropics can be both rich in species and complex in terms of stand structure. There is, moreover, a growing recognition of the importance of secondary forests for traditional subsistence economies in the tropics and of their economic potential for land use systems in the future. Management of secondary forests in Asia as an alternative to the extraction of timber from primary forests but also as one among other options to intensify traditional land use systems has a potential for the future especially because of the existence of vast tracts of valuable secondary forest cover, and because of the store of traditional knowledge that can still be found in tropical Asia.


2021 ◽  
Author(s):  
Madelon Lohbeck ◽  
Ben DeVries ◽  
Frans Bongers ◽  
Miguel Martinez-Ramos ◽  
Armando Navarrete-Segueda ◽  
...  

Forest regrowth is key to achieve restoration commitments, but we need to better understand under what circumstances it takes place and how long secondary forests persist. We studied a recently colonized agricultural frontier in southern Mexico. We quantified the spatiotemporal dynamics of forest loss and regrowth and tested how temporal variation in climate, and spatial variation in land availability, land quality and accessibility affect forest disturbance, regrowth and secondary forest persistence. Marqués de Comillas consistently exhibits more forest loss than regrowth, resulting in a net decrease of 30% forest cover (1991-2016). Secondary forest cover remained relatively constant while secondary forest persistence increased, suggesting that farmers are moving away from shifting cultivation. Temporal variation in disturbance and regrowth were explained by the annual variation in the Oceanic El Niño index combined with dry season rainfall and key policy and market interventions.Across communities the availability of high-quality soil overrules the effects of land availability and accessibility, but that at the pixel-level all three factors contributed to explaining forest conservation and restoration. Communities with more high-quality soils were able to spare land for forest conservation, and had less secondary forest that persisted for longer. Old forest and secondary forests were better represented on low-quality lands and on communal land. Both old and secondary forest were less common close to the main road, where secondary forests were also less persistent. Forest conservation and restoration can be explained by a complex interplay of biophysical and social drivers across time, space and scale. We warrant that stimulating private land ownership may cause remaining forest patches to be lost and that conservation initiatives should benefit the whole community. Forest regrowth and secondary forest persistence competes with agricultural production and ensuring farmers can access restoration benefits is key to success.


1997 ◽  
Vol 13 (6) ◽  
pp. 857-866 ◽  
Author(s):  
Xue Ying Zhuang ◽  
Richard T. Gorlett

ABSTRACTHong Kong is on the northern margin of the Asian tropics. The original forest cover was cleared centuries ago but secondary forest has developed since 1945 at many sites protected from fire and cutting. There are also older forest patches maintained behind villages for reasons of ‘feng shui’, the Chinese system of geomancy. All plants >2 cm dbh were identified and measured in forty-four 400-m2 plots. Detrended correspondence analysis showed a floristic continuum, with the montane sites (>500 m) most distinct and some overlap between lowland post-1945 secondary forest and the feng shui woods. The 30–40 year-old secondary forest is dominated by Persea spp. Montane forest is similar but lacks several common lowland taxa of tropical genera and includes more subtropical taxa. The feng shui woods have the most complex structure and contain some tree species not found in other forest types. Their origin and history is obscure but we suggest that both planting and selective harvesting have had a role in their current species composition


2020 ◽  
Vol 12 (18) ◽  
pp. 2918
Author(s):  
Yang Liu ◽  
Ronggao Liu

Forest cover mapping based on multi-temporal satellite observations usually uses dozens of features as inputs, which requires huge training data and leads to many ill effects. In this paper, a simple but efficient approach was proposed to map forest cover from time series of satellite observations without using classifiers and training data. This method focuses on the key step of forest mapping, i.e., separation of forests from herbaceous vegetation, considering that the non-vegetated area can be easily identified by the annual maximum vegetation index. We found that the greenness of forests is generally stable during the maturity period, but a similar greenness plateau does not exist for herbaceous vegetation. It means that the mean greenness during the vegetation maturity period of forests should be larger than that of herbaceous vegetation, while its standard deviation should be smaller. A combination of these two features could identify forests with several thresholds. The proposed approach was demonstrated for mapping the extents of different forest types with MODIS observations. The results show that the overall accuracy ranges 91.92–95.34% and the Kappa coefficient is 0.84–0.91 when compared with the reference datasets generated from fine-resolution imagery of Google Earth. The proposed approach can greatly simplify the procedures of forest cover mapping.


2019 ◽  
Vol 14 (1) ◽  
pp. 27-34
Author(s):  
Dian Nuraini Melati

Land use land cover change and forestry play an important role in the global environmental change. Anthropogenic activities in changing the land have caused earth surface change. This change has a role to increase the change of global greenhouse gases in the atmosphere which also causes the increase greenhouse gases emission. Land cover change and forestry are sectors which cause high carbon emission. Therefore, a study in land cover change and estimation of carbon emission becomes important. This study took place in Jambi Province where deforestation has been in a high pace. In 2009 and 2011, the dominant area is dryland agriculture mixed with bush followed by secondary forest, i.e. 25% and 18.6%, respectively (in 2009); and 37.1% and 18.9%, respectively (in 2011). For the secondary forest, the gain was caused by the conversion of dryland agriculture mixed with bush and shrub into secondary forest. The loss of secondary forest is the highest among other forest cover at around 87,765 Ha due to the conversion into bare land and dryland agriculture mixed with bush. Due to land cover change in Jambi Province, the estimation of nett emission in the period of 2009-2011 is 4.8 Mt CO2-eq/year.


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