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Analysis of temporal changes in land cover and landscape metrics of a managed forest in the west Black Sea region of northern Turkey: 1970-2010
(Northeast Forestry Univ, 2018) Zengin, Hayati; Değermenci, Ahmet Salih; Bettinger, Pete
Forest structure changes continuously by natural and anthropogenic effects. Because the level of goods and services provided by forest ecosystems are related to this structure, some attributes have to be controlled while they are being managed. In this paper we describe the long-term temporal changes in land area and landscape metrics related to different land uses of a managed forest in Turkey. The study was carried out for the Daday Forest Planning Unit located in the west Black Sea region of northern Turkey. The total area is 16,813 ha and besides wood production, it is managed for erosion control, public health, aesthetics, and recreation. Stand type maps that were constructed in 1970, 1989, 1999, and 2010 were used in this analysis. Transition matrixes that illustrate area changes among cover types and temporal changes on some landscape metrics were obtained using Geographic Information Systems. Stands were separated into small patches, and thus the number of patches increased nearly two-fold between 1970 and 2010. The total forest edge increased and through the associated fragmentation, the amount of core forest area decreased at the landscape scale. Landscape metrics were applied to digitized versions of historical maps to assess how forest area changed. Human use of the land has changed, forest management practices have evolved, and these along with natural forest growth have contributed to interesting changes in landscape character.
Analyzing the effect of carbon prices on wood production and harvest scheduling in a managed forest in Turkey
(Elsevier Science Bv, 2019) Zengin, Hayati; Ünal, Murat Engin
Among terrestrial ecosystems, forests have the largest carbon deposits, and thus play an important role in global climate change. Forests of all ages and types have a significant capacity in sequestration or depositing carbon. Increasing their capacities from this aspect can only be possible through sustainably managed forests. Therefore, in order to increase the carbon stock in forests, carbon management concepts must be integrated into the forestry program. The purpose of this study is to understand how carbon sequestration can affect levels of wood production and harvest scheduling in a forest area operated mainly for wood production, by considering alternative ideas on the current conditions in the given area. Monetary revenue which will be achieved by a 100-year planning horizon with a mixed integer optimization model, the produced wood and the levels of carbon that was sequestrated from atmosphere were investigated under 5 different strategies. Strategies were formed according to the potential unit prices of carbon. In the basic strategy (STR1) carbon price is taken as zero (only wood production revenue), while other strategies, i.e., STR2, STR3, STR4, and STR5 is priced as (sic)8, (sic)35, (sic)55, and (sic)100 per ton, respectively. Regeneration periods of stands and amount of maintenance cuts, which will be extracted from the forest, differ according to the strategies. Results show that when sequestrated carbon unit price is low (STR2 and STR3) or even when carbon has no value (STR1) the management activities in these strategies are almost the same. However, if there is an increase in the value of carbon (STR4 and STR5), with the assessment of different options, it is understood that a much higher level of revenue can be accessible.
Antioxidant Enzyme Activities and Some Biochemical Changes in Rainbow Trout Oncorhynchus mykiss (Walbaum 1792) Yolk-Sac Larvae
(Central Fisheries Research Inst, 2016) Zengin, Hayati; Yılmaz, Ökkeş; Gökçe, Zehra; Demir, Ersin
In this work we studied the biochemical status of antioxidant defences of yolk-sac larvae from the commercial fish, rainbow trout Oncorhynchus mykiss (Walbaum 1792) over a period of 19 days from hatching. The parameters studied were: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHpx), glutathione reductase (GR) and glutathione Stransferase (GST). Oxidative damage was measured by the formation of malondialdehyde (MDA). Our results showed that the presence of catalytic activities was observed from hatching day and significant changes in the enzymes were seen in the 12 and 19 days yolk-sac larvae, when the larvae finished their endogenous feeding. Our study indicates that catalase activity sharply increased in the 12 and 19 days post-hatch but superoxide dismutase activity sharply decreased in the same period. Glutathione peroxidase regularly decreased with age throughout the 19-day study period. Glutathione reductase showed a significant increase in the 12 and 19 days yolk-sac larvae. There were no significant changes in glutathione S-transferase activity throughout the yolk-sac stage. When the egg yolk-sac was reabsorbed, the total protein content sharply decreased at day 19. The PUFA contents in the 12 and 19 days yolk-sac larvae were found to be higher than in the other yolk-sac stage.
Arthropod diversity in pure oak forests of coppice origin in northern Thrace (Turkey)
(Sisef-Soc Italiana Selvicoltura Ecol Forestale, 2015) Keten, Akif; Beşkardeş, Vedat; Kumbaşlı, Meriç; Makineci, Ender; Zengin, Hayati; Özdemir, Emrah; Anderson, James T.
Oak (Quercus spp.) forests are among the most important forest types in Turkey. In the past, oak forests were managed through coppice clear-cutting, but in recent decades they have mostly been converted to high forest. This study was aimed at explaining how arthropod diversity is affected during conversion from coppice to high oak forest and during the early stages of coppice succession. We tested the hypothesis that arthropod richness, abundance and diversity in coppice oak sites varied according to stand age and a number of other forest characteristics. Arthropod communities were sampled in 50 plots using four different methods: pitfall traps, sweep nets, sticky cards and cloth shaking. A total of 13 084 individuals were collected and classified into 193 Recognizable Taxonomic Units (RTUs), with the most RTUs and the greatest number of specimens captured by sweep netting. We identified 17 taxa within RTU's with more than 1% of the captured arthropods, which constituted 75% of the total specimens. The number of RTUs varied significantly according to trap type. Arthropod richness and Shannon-Wiener biodiversity index (H') increased with elevation and precipitation. In young (1-40 yrs-old) and middle-aged (4180 yrs) stands, arthropod biodiversity was not significantly affected by stand type, but slightly increased with diameter at breast height and tree height. Forest characteristics, such as the litter layer, understory and crown diameter, weakly influenced arthropod richness and abundance. Cluster analysis revealed that stand types and trap types differed taxonomically. Principal component analysis showed that stand types were clearly separated by the stand parameters measured. Insect families (Formicidae, Thripidae, Lygaeidae, Dolichopodidae, Luaxanidae, Cicadellidae and Ichneumonidae) could potentially be used as indicators of coppice oak conditions. As the coppice oak changes to mature forest, further studies are needed to better assess the relation between arthropods, forest types and structural characteristics of stands.
Bird composition and diversity in oak stands under variable coppice management in Northwestern Turkey
(Sisef-Soc Italiana Selvicoltura Ecol Forestale, 2018) Beşkardeş, Vedat; Keten, Akif; Kumbaşlı, Meriç; Pekin, Burak; Yılmaz, Ersel; Makineci, Ender; Zengin, Hayati
Coppice management results in profound differences in forest structure and composition, which in turn can modify habitat value for bird species. We measured bird species richness and composition at 50 sample plots in pure oak forest stands in northwestern Turkey, which differed in age, cover and height in association with coppice management. We recorded a total of 38 bird species and 699 individuals across all stands. Regression-based multimodel inference showed that structural features of forest stands strongly affect bird diversity and abundance. While canopy cover and tree height affect bird diversity positively, elevation of sampling plots, tree density and tree diameter at breast height (DBH) had a negative effect. In addition, constrained ordination analyses revealed that canopy cover was the most important factor influencing bird species composition. Forest stands that have 42-85% canopy cover, i.e., a few (2009-2580 oak trees) large tall (13.36-15.78 m) trees, were the most preferred habitat by bird species. However, we also found that different bird species favor different stand structural features. Thus, variation in stand structure from maintaining some coppice management across the landscape may be beneficial for rare or endangered species and result in greater landscape level biodiversity.
Bolu ili arazi kullanım sınıflarına göre toprak üstü biyokütlede depolanan karbon miktarlarının NDVI ile belirlenmesi
(2023) Değermenci, Ahmet Salih; Zengin, Hayati
Bu çalışmada Bolu ili 1990, 2006 ve 2018 yılları arazi sınıfı durumları ve dönemler arası arazi sınıfı geçişleri incelenmiştir. Ayrıca 1990-2018 yılları için arazi kullanım sınıfları toprak üstü biyokütlelerinde (TÜB) depolanan karbon miktarları NDVI uydu görüntüleri üzerinden belirlenmiştir. Arazi sınıflarının değişimini belirlemek için CORINE arazi sınıflandırması kullanılmıştır. 1990 ve 2018 yıllarında karbon depolama miktarlarını belirlemek için Landsat 5 TM ve Landsat 8 OLI uydu görüntüleri kullanılmıştır. Arazi sınıflarından yapay yüzeylerde 28 yıllık süreçte yaklaşık %81.56’lık artış olmuştur. Tarım alanlarında ise toplamda %2.87 (5539.8 ha) oranında artış yaşanmıştır. Orman ve yarı doğal alanlar ise aynı dönemde %1.83 (11745.5 ha) oranında azalmıştır. 28 yıllık süreçte su kütlesi alanları ise yaklaşık 3.4 kat artmıştır. Arazi sınıfı AGB’deki karbon miktarları bakımından 28 yıllık süreçte yaklaşık %59.5 karbon birikmesi olmuştur. 1990 yılında Arazi sınıfları AGB’sinde toplam 1583467.3 ton karbon depo edilmişken, 2018 yılında bu miktar 2664549.5 ton karbona yükselmiştir. 1990 yılında depolanan toplam karbonun %82.5’i orman alanlarında ve % 17’si de tarım alanlarında depolanmıştır. 2018 yılında ise toplam karbonun %76.3’ü orman ve yarı doğal alanlarda, %23’ü de tarım alanlarında depolanmıştır. Bu 28 yıllık süreçte, farklı bir arazi sınıfına dönüştürülmemiş arazi kullanım/arazi örtüsü sınıflarının TÜB'lerinde toplam 1000151.7 ton karbon birikmiştir. Dönüşüme uğrayan araziler üzerinden de toplam 80930.6 ton karbon bir arazi sınıfından diğerine taşınmıştır. Toplamda 1990-2018 yılları arasında 1081082.3 ton karbon birikimi meydana gelmiştir.
Determination of temporal changes in land uses in Hasanlar Dam basin
(Istanbul Univ, 2018) Zengin, Hayati; Özdemir, Hakan Yasin; Değermenci, Ahmet Salih
The impact of human activities on nature is increasing day by day along with changing patterns of land use. These changes also influence the level of the expected function of natural ecosystems. Therefore, for the purposes of meeting the needs of a growing population for ecosystem services at optimal levels, it is important to understand and control the factors that affect land use and to control the changes in land use according to the objectives. The aims of this study were to determine land-use patterns in Hasanlar Dam basin per period, analyze the temporal changes in land use according to area, and determine the reasons for the changes in the basin by digitizing the maps of the basin area belonging to the period between 1986 and 2010. Forest land-use patterns were categorized into the following six groups: forest, (deciduous, coniferous, mixed, and degraded), forest gaps, hazelnut, agriculture, pasture, and other areas. The forest area that was 64,843 ha in 1986 had declined to 62,709 ha in 2010. Hazelnut areas covering an area of 3,636 ha in 1986 were represented as agricultural areas in the 2010 stand maps. The agricultural areas that were 8,925 ha in 1986 increased to 15,420 ha in 2010. The pasture areas comprising 267 ha in 1986 decreased to 19 ha in 2010. Other areas decreased from 1,302 ha to 825 ha between 1986 and 2010. Through the Melen project, water is being transported to Istanbul from Hasanlar Dam. Therefore, since changes in the land-use pattern in the Hasanlar Dam basin may affect both water efficiency hydrologically and the quality of water, it is necessary to monitor the changes in forest, agriculture, pasture, forest soil, and other areas and also the changes in the demographic structure. In addition, it must be ensured that these changes cause the minimum impact on water yield and quality.
Determining plant species diversity of Scots pine stands in the Bolu Aladag region of Turkiye
(Univ Austral Chile, Fac Ciencias Forestales, 2023) Gurkan, Mustafa; Zengin, Hayati; Ozcan, Mehmet; Degermenci, Ahmet Salih; Aksoy, Necmi
This study aims to determine how plant diversity changes at the alpha and gamma levels depending on stand type. Also, it tries to understand how plant diversity changes temporally and with relation to aspects during a given vegetation period. Sample areas were selected from pure Scots Pine stands with full canopy cover (70 - 100 %) and in different development stages (a, b, c, d) spread out within the Bolu Aladag region of Turkiye. Field studies were carried out in 2016 from June-September. Sample stands were selected to cover two main aspects, north and south. The study was carried out by analyzing two repetitive and 10 quadrate samples in each stand. A total of 640 quadrate samples were analyzed, and the different plants were counted. In the study area, a total of 160 taxa were identified at the DUOF Herbarium. It was determined that while the stand type did not have a significant effect on taxon diversity, the effect of aspect and observation period was statistically significant (P < 0.05). Shannon index value was between 3.13 and 3.72 among the stands' different development stages, with the highest values found in the young stands. Diversity was higher on Northern aspects than Southern and rose and fell throughout the observation period with the highest values in June and August. Interestingly, while there was no significant effect of stand development stages on taxon diversity, a significant but low correlation has been found between stand diameter and evenness.
Diversity and ecology of forest communities in Kure Mountains National Park of Turkey
(Univ Austral Chile, Fac Ciencias Forestales, 2020) Tunckol, Bilge; Aksoy, Necmi; Coban, Suleyman; Zengin, Hayati
This study aimed at analyzing the diversity and ecological characteristics of forest associations (121 releves classified under eight associations) in Ktire Mountains National Park. Ordination analyses (DCA and CCA) and response curves were used to reveal ecological characteristics of vegetation using soil parameters (pH, electrical conductivity, sand, clay and dust content, soil moisture) and topographical variables (altitude, slope, potential direct incident radiation and heat load). Ecological conditions of communities were also tested using average Ellenberg indicator values (EIVs). Among forest associations, the highest species diversity was found in Phillyreo latifoliae-Pinetum brutiae and the lowest diversity in Hedero-Castanetum sativae, which had a dense Rhododendron ponticum shrub layer. However, Salicio-Platanet um orientale and Buxo sempervirens-Ccupinetum betuli had the highest beta diversity since they harbored unique species composition. Conditional effects of altitude, slope, pH and electrical conductivity, soil dust and sand content, sandy-loam and loam soil types presented significant contributions in species composition. While Carpino-Querretum petraeae was found on soil with high dust content having high pH and electrical conductivity values, Quercetum roburi-Aceretum campestri and Salicio-Platanettun orientale were related to soil with loam. Species responses to soil and topographical variables varied for most tree species. Light EIVs, which has a high positive correlation with potential direct incident radiation and heat load, related to Phillyreo latifoliae-Pinetum brutiae and Salicio-Platanetum orientale. Riverside forest communities diffixed from other communities in nutrient and humidity EIVs. However, EIVs did not show a good correlation with associated soil parameters such as soil moisture-humidity EIVs and soil pH-acidity EIVs.
Düzce Asar Orman İşletme Şefliğinde Arazi Metriklerindeki Zamansal Değişimler
(Düzce Üniversitesi, 2020) Keten, Serap; Zengin, Hayati
Ekosistemlerde meydana gelen değişimlerin (delinme, parçalanma, bozulma,küçülme, aşınma) belirlenmesi; gelecekte oluşacak sorunların çözümüne yönelikönlemlerin alınması ve canlı yaşamı ve yaşam alanlarındaki ilişkilerinkorunması açısından önem taşımaktadır. Doğal alanların farklı yapılara sahiptirve habitat parçalanması mekansal ölçülebilir özellikler ve süreçlerdir. Peyzajmetrikleri (Landscape metrics), bu süreçlerin daha iyi anlaşılmasını sağlar.Metrikler, mekansal yapıyı belirli bir zamanda tanımlarlar. Doğal alanlarüzerinde hesaplanan metriklerin zamansal olarak değişiminin ortaya konulmasısürdürülebilir doğal alan yönetimi için doğru çıkarımlar yapılmasını sağlayacaktır.Ancak bu tip çalışmalar ülkemizde sınırlıdır. Bu çalışmada Bolu Orman BölgeMüdürlüğü Düzce Orman İşletme Müdürlüğü Asar Orman İşletme Şefliği yönetimalanındaki arazi kullanımlarının 1968, 1987 ve 2010 yılları arasındaki peyzajmetriklerinin değişimi ortaya konulmaya çalışılmıştır. Verimli ormanların alanıartarken bozuk vasıflı alanlar ve ormansız alanlar azalmıştır. Diğer taraftanormanlık alanlardaki leke sayısı artmıştır. Bu durum leke çeşitlilik indeksinipozitif etkilemiştir.
Effects of some watershed characteristics on water yield in the West Black Sea Region of northern Turkey
(Univ Austral Chile, Fac Ciencias Forestales, 2017) Zengin, Hayati; Özcan, Mehmet; Değermenci, Ahmet Salih; Çitgez, Tarık
This paper presents the effect of some watershed characteristics on water yield based on two-year measurements (2015-2016) realized at 29 watersheds. Although, there are several factors affecting the runoffs, we tried to eliminate some and focused on watershed characteristics by choosing the watersheds as near as to each other in the same hydro-climatic zone. These are relatively small watersheds (8.6-449.3 ha) at the mountainous and forested areas around Duzce city, Turkey. Elevation of most watersheds, which is effective on precipitation, is above 1,000 m and covered by snow in winter. Regression models between water yield or runoff coefficient based on water yield/precipitation ratio and some watershed characteristics can be important to estimate the amount of water and manage the forest for its hydrologic function. In this study, the effect of watershed area, form factor, mean slope, drainage density, elevation, circularity and elongation ratios on water yield and runoff coefficient was analyzed by multiple linear regression analyses. While there is not a significant relation between runoff coefficient and watershed characteristics, we constructed a significant regression model for estimating water yield depending on watershed characteristics. Watershed size, elevation, form factor and elongation ratios are found as effective variables on water yield. When other variables (ratio of circularity, mean slope, drainage density) were added, adjusted R-2 and significance of the model was decreased. Results showed that some watershed characteristics have a significant effect on water yield, and equations based on these characteristics can be used in forest management or policy making in determining the priority of watersheds for water production.
Evaluating the Accuracy of Remote Dendrometers in Tree Diameter Measurements at Breast Height
(Zagreb Univ, Fac Forestry, 2022) Uçar, Zennure; Değermenci, Ahmet Salih; Zengin, Hayati; Bettinger, Pete
An accurate tree diameter (DBH) measurement is a significant component of forest inventory. This study assessed the reliability of remote dendrometers to measure tree DBH. We compared direct caliper measurements (reference measurements) to the remote measurements collected from a laser caliper and a smartphone at 0.5 m, 1 m, and 1.5 m distances from each tree within three forest types (pine, oak, and poplar forests). In general, all remote dendrometers underestimated the mean diameter compared to direct caliper measurements, regardless of forest types and distances. We observed that the mean deviation of direct caliper measurement and smartphone measurement at 1.5 m within a pine forest and oak forest were the lowest (0.3 cm and 0.36 cm, respectively). The deviations between direct caliper measurements and smartphone measurements at a 0.5 m distance, across forest types, were noticeably larger compared to others. An ANOVA test was used to determine whether significant deviations existed between caliper measurements and remote measurements at a specific distance, and among three different forest types. We rejected the null hypothesis, which suggested that there were no statistically significant differences (p<0.05) between tree DBH measurements obtained from the direct caliper measurements and indirect measurements (smartphone and laser caliper) captured at a distance. Then, a post-hoc test was performed to examine which set of estimated deviations was different from the reference data. The results suggested that indirect tree DBH measurements using the smartphone app at 1 m and 1.5 m in certain forest types (pine and oak) were not significantly different from direct tree DBH measurements. Also, our test results mostly indicated no significant difference within each forest, except for measurements using the smartphone app at 0.5 m across all forest types when the smartphone measurements were compared to laser caliper measurements. Although forest characteristics and measurement distance may play an important role in remote tree DBH measurement accuracy, the smartphone app may be used as a practical alternative to direct measurement in measuring the DBH of a tree, which may be a positive development for forestry due to the increased use of smartphones and the availability of a free measure app.
Evaluation of forest management plans in conjunction with the cadastral information: The case of Agva and Beykoz, Istanbul
(Istanbul Univ, Fac Forestry, 2016) Çakır, Günay; Güler, Alptuğ; Zengin, Hayati; Değermenci, Ahmet Salih
Determination of land ownership and boundaries is one of the most important purposes of the urban and rural land laws. There can be some boundary problems while preparing forestry area of any urban area when there is not consistency between the borders constructed by different state organizations like land cadastre, forest cadastre and forest management and planning teams. This study aims to illustrate these conflicts in forestry applications process of two different areas (Agva and Beykoz) having different characteristics. The study was carried out in Agva and Beykoz districts in the province of Istanbul and focused on the integration in the land and forest cadastral systems. The Beykoz and Agva Forest Planning Units have different characteristics in terms of population (urban and rural) and social impacts. Analyses of the data obtained from the field studies which it was utilized for the investigation of the data obtained from various base maps, were carried out using GIS software. Many inhabitants of the villages in the Agva Planning Unit had migrated from the district. Thus, in accordance with Boundary Law number of 6831 part of 2/B some parcels of villages in Agva were determined to be acting forest and were reassigned as forest land. In Beykoz, however, areas of this nature were few and the destruction of the forests was great. The spatial analysis of the study made it possible to remove discrepancies occurring in the cadastral situation by preparing forest management plans. Consequently, if land cadastre and forest cadastre units carry out work in coordination to determine the cadastral situation, a basis for forest management plans can be established and cadastral problems greatly reduced.
Evolution of Modern Forest Management Planning in the Republic of Turkey
(Soc Amer Foresters, 2013) Zengin, Hayati; Yeşil, Ahmet; Asan, Ünal; Bettinger, Pete; Cieszewski, Chris; Siry, Jacek P.
The Republic of Turkey has a long history of forest management that has undergone considerable change over the last 100 years due to political, economic, and social issues. For the most part, state-owned forestlands (the largest forest owner category) have been managed under plans arising from a conventional process that used classic techniques to regulate activities and allowable harvest levels. However, over the last 35 years, four different types of forest management plans have been developed (conventional and model) and applied universally or to a specific region of the country. Today, a single type of planning process is used, which emphasizes ecological and environmental conditions, multiple uses of the landscape, and social concerns. Although management and planning are evolving, implementation is challenged by a continued focus on wood production rather than on other concerns, a lack of skilled personnel and qualified decisionmakers, and other societal conflicts.
Forest management issues of the southern United States and comparisons with Turkey
(Tubitak Scientific & Technical Research Council Turkey, 2013) Bettinger, Pete; Siry, Jacek; Cieszewski, Chris; Merry, Krista L.; Zengin, Hayati; Yeşil, Ahmet
Most of the forest area in the southern United States has been cleared, regrown, purchased, and sold several times over the last 200 years, and forest management practices generally focus on wood production. Agricultural expansion, use, and the abandonment of land have been the major forces behind land use change, and now human population expansion is a major issue. The land tenure system of the United States has allowed individuals and companies to acquire, use, and sell land since the time of European colonization; thus, private ownership of land dominates the southern region. However, new private, corporate, nonindustrial entities have arisen in the last 20 years, mainly as a result of tax policies and changes in industrial business organizations. While in Turkey planning systems are centralized, these systems vary by landowner group in the southern United States. They range from those that are relatively absent (nonindustrial private landowners) to those that are very formal (national forests). The management of forests in the southern United States is also guided by a number of federal, state, and local policies rather than a single enterprise plan, and these policies affect the direction of both public and private forest management. Specifically with regard to public land, the mission and objectives of forestry are similar to those in Turkey, except when considering the needs of local citizens, which has been given greater emphasis in Turkish forest management and planning.
Gökkuşağı Alabalığı Oncorhynchus mykiss (Walbaum 1792)’in Keseli Larvalarında Antioksidan Enzim Aktiviteleri ve Bazı Biyokimyasal Değişimler
(2016) Zengin, Hayati; Yılmaz, Ökkeş; Gökçe, Zehra; Demir, Ersin
Bu çalışmada ticari olarak yetiştirilen gökkuşağı alabalığı Oncorhynchus mykiss (Walbaum 1792)'in keseli yavrularında, yumurtadan çıktıktan sonraki 19 gün boyunca antioksidan savunma ve biyokimyasal durum çalışıldı. Çalışılan parametreler: süperoksit dismutaz (SOD), katalaz (CAT), glutatyon peroksidaz (GSHpx), glutatyon redüktaz (GR) ve glutatyon-s-transferaz (GST)'dır. Oksidatif hasar malondialdehit (MDA) oluşumu ile ölçüldü. Sonuçlarımız yumurtaların açıldığı günden itibaren katalitik aktivitenin mevcut olduğunu ve larvalar endojen besini kullanırken, 12 ve 19 günlük keseli larvalarda bulunan enzimlerde önemli değişimlerin olduğunu gösterdi. Çalışmamız yumurtaların açılmasından sonraki 12. ve 19. günlerde katalaz aktivitesinde hızlı bir artma, aynı periyotta süperoksit dismutaz aktivitesinde ise hızlı bir azalma gösterdi. Glutatyon peroksidaz 19 günlük çalışma süresi boyunca düzenli bir şekilde azaldı. Glutatyon redüktaz 12 ve 19 günlük keseli larvalarda önemli bir artış gösterdi. Keseli safha boyunca glutatyon-s-transferaz aktivitesinde önemli bir değişim olmadı. 19. günde yumurta kesesinin emilimiyle total protein içeriği hızla düştü. 12 ve 19 günlük keseli larvalardaki PUFA içeriği, diğer keseli safhalardan yüksek bulundu
Integration of Cadaster Information with Forest Management and Planning
(Düzce Üniversitesi, 2017) Çakır, Günay; Güler, Alptuğ; Zengin, Hayati; Değermenci, Ahmet Salih
Planning of forests is realized based on determined rules and methods. Ensuring the sustainability of forestry area is directly related with sustainability of both of the technical and economical utilization. One of the most important subjects in protecting forest properties is the assurance of ownership. In the context of this study, changes in the practices of general forest management and cadaster in the republic period were tried to examine and its results were focused on. Important problems are faced on in reflecting the ownership to the plan preparing process. Althought, improving techniques facilitates the occupation in planning; also the cadastral problem by sociological situation of our country hasn’t to be integrated to forest planning. Because implementing forestry in the areas clarified from ownership problems will be easy, it is important to establish the needed infrastructure to solve these problems. It is necessary to remove technical biases formed in the past years because of impossibilities and take the maps constructed for land register into a situation comparable with the forest cadaster maps. Subjects related with ownership were realized in 14 villages in Ağva and Beykoz Forest Planning Units which were chosen as study area . As a result of the evaluations it is detected that different attribute assignments were done for both of the study areas. Because there is a migration out in the villages of Ağva, forests allocated as 2-2/B in recent years depending on 6831 numbered forest code were transformed into acting forest. In Beykoz Planning Unit, it is determined that amount of acting forests are relatively less while opening from forests and invasion is high. In the study, all of the data analysis and queries were realized by using Geographic Information Systems (GIS).
MODELING HARVEST SCHEDULING IN MULTIFUNCTIONAL PLANNING OF FORESTS FOR LONGTERM WATER YIELD OPTIMIZATION
(Wiley-Blackwell, 2015) Zengin, Hayati; Asan, Ünal; Destan, Sinan; Ünal, Murat Engin; Yeşil, Ahmet; Bettinger, Pete; Değermenci, Ahmet Salih
In this study, wood production and hydrologic functions of forests were accommodated within a planning procedure for separate working circles (areas dedicated to certain forest functions) that were delineated according to an Ecosystem-Based Functional Planning approach. Mixed integer goal programming was used as the optimization technique. The timing and scheduling of a maintenance cutting (partial harvest) was the decision variable in the modeling effort, and an original formulation was developed as a multiobjective planning procedure. Four sample planning strategies were developed and model outputs were evaluated according to these strategies. Spatial characteristics of stands were considered, and used to prohibit the regeneration of adjacent stands during the same time period. Because of the positive relationship between qualified water production and standing timber volume in the forest, the model attempts to maximize qualified water production levels by increasing standing volume stocks in the forest through the delay of regeneration activities.
Multiple linear regression models for the estimation of water flows for forest management and planning in Turkiye
(Water Research Commission, 2023) Zengin, Hayati; Ozcan, Mehmet; Degermenci, Ahmet Salih; Citgez, Tarik
While there are many factors, including climatology, geography, topography, vegetation and soil, that affect hydrologic processes, understanding the role of forests seems most essential, due to their manageable nature. In this study, a holistic approach was taken, and possible factors affecting streamflow, including tree, sapling, shrub, herb and soil strata, were measured for 29 small catchments/stream basins located in Turkey. Linear regression models were developed in order to estimate water flow (m3 & BULL;ha-1). Several models were suggested for use in practice. These models were based on the data on hand and displayed a sufficient level of explained variance in the dependent variable. Model 5, based on the variables of catchment area (ha), drainage density, ratio of coniferous stand areas in the catchment (%), tree volume (m3 & BULL;ha-1), leaf area index, number of short saplings (number & BULL;ha-1), and topsoil sand rate (%), was recommended for flow estimation, achieving a 0.73 adjR2 value for test data. These variables can be obtained as part of a survey and water managers can use them to estimate water flow of the catchment. The generated models can be used in multiple-use planning of forests, e.g. in adjusting the volume of stands to get optimum benefit from wood and water production. One of the most interesting results and one that was opposite to that documented in the general literature, was the positive correlation between tree volume and flow per hectare, which suggests a strategy of growing older tree stands to enable greater water production.
Optimization of water yield, carbon storage and wood production in forest planning by mixed integer programming
(Univ Austral Chile, Fac Ciencias Forestales, 2022) Değermenci, Ahmet Salih; Zengin, Hayati; Ünal, Murat Engin
Interventions to the forest also affect the amount and quality of water and carbon storage; revenues to be obtained from these areas as well. Therefore, for the long-term estimation of the harvest plans to be organized, it is necessary to eliminate the lack of information for other functions provided by the forests and to quantify their relationship with forest dynamics. In this study, it was intended to determine how forest functions, such as wood production, hydrologic and carbon storage functions, changed according to different objective functions and constraints and what kind of harvest scheduling is prepared in line with a planning process. Seven different planning strategies have been developed for the Cicekli planning unit, aimed at maximizing profit according to these different strategies. Among the developed strategies, the highest objective function value (500,704,847 TL) was obtained in the strategy 6 (ST6), where there is no Optimal Periodic Area (OPA) constraints. The highest amount of water (894,728,400 m(3)) was obtained in the strategy 7 (ST7), which has a constraint on the amount of area to be regenerated. While the amount of carbon stored in the planning unit decreased due to the high amount of regenerated area in most planning strategies, only in ST7 it has increased in all periods, showing periodic regeneration constraints. At the end of the planning horizon, the amount of growing stock (2,446,402 m(3)) has increased only in ST7 with regeneration constraints, whereas the amount of growing stock has decreased in all other strategies.

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