Ahmet Yeşil

Prof. Dr. Ahmet Yeşil

Istanbul University Cerrahpasa, Faculty of Forestry

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 December 2013 in European Journal of Forest Research
Verified
Journal Article
Closed access
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Sergio de MiguelSergio de Miguel
Sergio de Miguel
TPTimo Pukkala
Timo Pukkala
Ahmet YeşilAhmet Yeşil
Ahmet Yeşil

8 August 2020 in Forests
Verified
Journal Article
Open access
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AGAlba Gutierrez Garzon
Alba Gutierrez Garzon
Pete BettingerPete Bettinger
Pete Bettinger
Jacek SiryJacek Siry
Jacek Siry
Jesse B. AbramsJesse B. Abrams
Jesse B. Abrams
Chris CieszewskiChris Cieszewski
Chris Cieszewski
Ahmet YeşilAhmet Yeşil
Ahmet Yeşil
International expansion of forest certification programs has occurred over the last three decades. Both public and private organizations have shown increased interest in becoming certified by one or more forest certification bodies, to assure the public that forest resources are managed adequately in sustaining forest health and socio-economic viability. The Forest Stewardship Council (FSC) program is globally used as a benchmark to implement forest certification at the national and regional levels. The Sustainable Forest Initiative (SFI) and the American Tree Farm System (ATFS) are also used throughout the United States. In Europe, individual countries such as Bulgaria and Turkey have also developed national forest certification programs. The SFI, ATFS and Bulgarian programs are further endorsed by the Programme for the Endorsement of Forest Certification (PEFC). The results of a qualitative analysis comparing the FSC forest certification program with the SFI, the ATFS, and the two European national programs (Bulgarian and Turkish) suggest that differences in these programs are not necessarily related to their language, but to the level of detail and prescriptiveness of each program. We find that the FSC is much more detailed and prescriptive in nearly all aspects considered for forest certification. In particular, we find that most of the elements considered in the FSC Principle 6 (Environmental Impact) are either only superficial, or not addressed at all, in the other four programs. Furthermore, the other programs appear to be less comprehensive and detailed in the substance of the FSC monitoring and assessment principles. In a few areas, the Turkish program requires more quantitative indicators for assessing forest management than the other programs. Though a comparison of the legal framework related to forest management in each of the studied countries was briefly introduced, our study focuses on the certification schemes themselves; it may contribute to policy discussions in the future development and implementation of other certification programs.

11 May 2018 in Forest Ecosystems
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Journal Article
Open access
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MAMALIHEH arekhi
MALIHEH arekhi
Ahmet YeşilAhmet Yeşil
Ahmet Yeşil
UOUlas Yunus Ozkan
Ulas Yunus Ozkan
Fusun Balik SanliFusun Balik Sanli
Fusun Balik Sanli
Treeline dynamics have inevitable impacts on the forest treeline structure and composition. The present research sought to estimate treeline movement and structural shifts in response to recent warming in Cehennemdere, Turkey. After implementing an atmospheric correction, the geo-shifting of images was performed to match images together for a per pixel trend analysis. We developed a new approach based on the NDVI, LST (land surface temperature) data, air temperature data, and forest stand maps for a 43-year period. The forest treeline border was mapped on the forest stand maps for 1970, 1992, 2002, and 2013 to identify shifts in the treeline altitudes, and then profile statistics were calculated for each period. Twenty sample plots (10 × 10 pixels) were selected to estimate the NDVI and LST shifts across the forest timberline using per-pixel trend analysis and non-parametric Spearman’s correlation analysis. In addition, the spatial and temporal shifts in treeline tree species were computed within the selected plots for four time periods on the forest stand maps to determine the pioneer tree species. A statistically significant increasing trend in all climate variables was observed, with the highest slope in the monthly average mean July temperature (tau = 0.62, ρ < 0.00). The resultant forest stand maps showed a geographical expansion of the treeline in both the highest altitudes (22 m–45 m) and the lowest altitudes (20 m–105 m) from 1970 to 2013. The per pixel trend analysis indicated an increasing trend in the NDVI and LST values within the selected plots. Moreover, increases in the LST were highly correlated with increases in the NDVI between 1984 and 2017 (r = 0.75, ρ < 0.05). Cedrus libani and Juniperus communis spp. were two pioneer tree species that expanded and grew consistently on open lands, primarily on rocks and soil-covered areas, from 1970 to 2013. The present study illustrated that forest treeline dynamics and treeline structural changes can be detected using two data sources. Additionally, the results will have a significant contribution to and implication for treeline movement studies and forest landscape change investigations attempting to project climate change impacts on tree species in response to climate warming. The results will assist forest managers in establishing some developmental adaptation strategies for forest treeline ecotones.

1 March 2020 in Applied Geography
Verified
Journal Article
Closed access
ICİnCi Caglayan
İnCi Caglayan
Ahmet YeşilAhmet Yeşil
Ahmet Yeşil
CCChris Cieszewski
Chris Cieszewski
FGFatmagül Kılıç Gül
Fatmagül Kılıç Gül
ÖKÖzgür Kabak
Özgür Kabak

11 July 2013 in Journal of Forestry
Verified
Journal Article
Closed access
HZHayati Zengin
Hayati Zengin
Ahmet YeşilAhmet Yeşil
Ahmet Yeşil
ÜAÜnal Asan
Ünal Asan
Pete BettingerPete Bettinger
Pete Bettinger
CCChris Cieszewski
Chris Cieszewski
JSJacek P. Siry
Jacek P. Siry

3 December 2016 in Journal of Forestry Research
Verified
Journal Article
Closed access
PDF file
UOUlas Yunus Ozkan
Ulas Yunus Ozkan
IOIbrahim Ozdemir
Ibrahim Ozdemir
TDTufan Demirel
Tufan Demirel
SSSerhun Saglam
Serhun Saglam
Ahmet YeşilAhmet Yeşil
Ahmet Yeşil