Faculty Opinions recommendation of Deficits of biodiversity and productivity linger a century after agricultural abandonment.

Author(s):  
Josep Canadell
2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Roxanne Lai ◽  
Takashi Oguchi

<p><strong>Abstract.</strong> Changing land use is an increasingly important issue as human habits, behaviors, and needs change. There has been an increase in land and agricultural abandonment in some places of the world. In Japan, movement of the population from rural to urban areas have resulted in much land and agricultural abandonment. In 2016, a land ministry survey showed that 4.1 million hectares of land in Japan had unclear ownership, with farmland making up 16.9% of the total. As vegetation cover changes after land abandonment, this temporal and spatial effect may have important effects on geomorphic processes such as landslide susceptibility and landslide kinematics.</p><p>Here we track long-term land use changes over vegetated landslide areas of the Sanbagawa and Mikabu Belts of Shikoku Island, Japan. The Sanbagawa and Mikabu Belts are metamorphic belts that run across Southwest Japan, and are home to numerous large crystalline schist landslides, including the widely-studied slow but continuously moving Zentoku landslide. Villages and communities have been built on these landslide areas due to historical and cultural factors, as well as the fertility of the soil. Consequently, given the changing land uses including land abandonment in these landslide areas over time, we use long-term high-resolution land cover vegetation datasets to examine first the long-term land use changes, and then use statistical methods to explore their relationships with landslide susceptibility and kinematics. Mapping of spatial data and their analysis using GIS constitute a core part of the research. The results suggest interconnections between land use changes and land movement.</p>


2017 ◽  
Vol 332 ◽  
pp. 3-15 ◽  
Author(s):  
Alemayehu Adugna ◽  
Assefa Abegaz ◽  
Asmamaw Legass ◽  
Diogenes L. Antille

Africa has seen significant changes in land cover at different spatial scales. Changes in Land Use and Land Cover (LULC) include deforestation and subse- quent use of the land for arable cropping, conversion to grassland or urbanization. The work reported in this article was conducted to examine land cover transi- tions in north-eastern Wollega (Ethiopia) between 2005 and 2015. The analysis focused on land cover transitions that occurred systematically or randomly, and identified the main drivers for these changes. Landsat data from 2005 and 2015 were examined to better unders- tand the various dimensions of land cover transitions, namely: swaps, losses, gains, persistency and vulnerability. Results showed that shrubland exhibited the largest gain (22%), with a 63% gain- to-loss ratio, a 47% gain-to-persistence ratio and a positive net change-to-persis- tence ratio of 46%. Cropland showed the largest loss (19%) while grassland was the most stable type of land cover des- pite some fluctuation (»10%) observed during the 10-year period. The land cover transition was dominated by systematic processes, with few random processes of change. Systematic land cover transitions such as agricultural abandonment and vegetation re-growth were attributed to regular or common processes of change. This study suggests that the implementa- tion of practices conducive to sustainable intensification of existing agricultural land, supported by policies that promote increased diversification of Ethiopian agriculture, would mitigate pressure on forests by avoiding their future conver- sion to cropland.


2019 ◽  
Vol 11 (23) ◽  
pp. 2759 ◽  
Author(s):  
Tomáš Goga ◽  
Ján Feranec ◽  
Tomáš Bucha ◽  
Miloš Rusnák ◽  
Ivan Sačkov ◽  
...  

This study aims to analyze and assess studies published from 1992 to 2019 and listed in the Web of Science (WOS) and Current Contents (CC) databases, and to identify agricultural abandonment by application of remote sensing (RS) optical and microwave data. We selected 73 studies by applying structured queries in a field tag form and Boolean operators in the WOS portal and by expert analysis. An expert assessment yielded the topical picture concerning the definitions and criteria for the identification of abandoned agricultural land (AAL). The analysis also showed the absence of similar field research, which serves not only for validation, but also for understanding the process of agricultural abandonment. The benefit of the fusion of optical and radar data, which supports the application of Sentinel-1 and Sentinel-2 data, is also evident. Knowledge attained from the literary sources indicated that there exists, in the world literature, a well-covered problem of abandonment identification or biomass estimation, as well as missing works dealing with the assessment of the natural accretion of biomass in AAL.


2019 ◽  
Vol 3 (11) ◽  
pp. 1533-1538 ◽  
Author(s):  
Forest Isbell ◽  
David Tilman ◽  
Peter B. Reich ◽  
Adam Thomas Clark

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