Lokman Altun

Relationship between site index of oriental spruce [Picea orientalis (L.) Link] and ecological variables in Maçka, Turkey

Abstract Oriental spruce [Picea orientalis (L.) Link] is a species native to Turkey, covering about 350,000 ha. The species is of great importance to the production of timber as well as to the creation of social welfare in eastern Black Sea region. There are few studies about ecological variables affecting oriental spruce site productivity. Based on data from 90 sample plots, multiple regression models were developed using topographic, edaphic, soil nutrients, climatic subgroups and all factors integrated. Within the different subgroups of site factors, the integrated model with all ecological variables provided the best statistical results, which explained 77% of index variation. Other topographic, edaphic, soil nutrients and climatic subgroup models were enumerated by the success of modelling site index of oriental spruce from the related site variables. The results show that the integrated model is more successful than the models developed separately for each ecological variable. However, the integrated model included 12 different variables and thus the assessment of some of these model variables, e.g. element content of the soil (Ca2+, Mg2+, etc.), require potentially laborious soil analyses and costly applications. Therefore, the topographic model with only three variables (R 2=0.656), which can be assessed directly from digital maps by Geographical Information System (GIS), seems to be more promising and convenient, since the model can be easily applied to large areas. The results can be translated into practical recommendations to forest managers for selecting suitable site conditions for oriental spruce.

Comparing methods for determining forest sites: a case study in Gümüşhane-Karanlıkdere forest

Forest site classification has long been a problem for managers of Turkish forests. Forest management decisions and land use planning involving afforestation activities and silvicultural prescriptions are based on sound site information to formulate appropriate actions on the ground. In Turkey, two methods of forest site productivity are used; direct and indirect method. Indirect methods are usually reserved for practical applications as they are relatively simple, yet provide less accurate estimation of the real productivity. In this study direct, indirect and remote sensing (RS) methods were used to distinguish and map forest sites of Karanlikdere Forest District in Gumushane, Turkey. One hundred and twenty-two sample plots were established with 300 m × 300 m grids in summer of 2003. In each sample plot, soil samples and the classical timber inventory measurements were taken. According to direct method, water-air economy method is preferred due to a water deficiency in the study area. Four different forest site classes; very dry, dry, moderate fresh and fresh were determined and mapped with geographic information system (GIS). In indirect method, the guiding curve was used to generate anamorphic site indexes (SI) of three classes; good (SI = I and II), medium (SI = III) and poor (SI = IV and V). Furthermore, forest sites were estimated with Landsat 7 ETM (2000) data using supervised classification with a 0.843 kappa statistic value and 88% accuracy assessments. Some important differences between the methods were discovered. The indirect method indicate that site indices I and II are 298.5 ha, III 254.3 ha and IV and V 347.7 ha. In contrast, direct method related to very dry site of 107.7 ha, dry site of 484.6 ha, moderate fresh site of 304.7 ha and fresh site of 246.3 ha. Satellite image indicate that very dry site covers 291.2 ha, dry site 239.2 ha, moderate fresh site 287.4 and fresh site 325.5 ha. Approximately 242.8 ha area (open and degraded areas) were not determined by indirect method but were captured with RS method. The statistical analyses (ANOVA) showed no statistically significant (F = 0.720, p = 0.543) relationship between indirect method and direct method-RS method indicating clearly that indirect method is not an adequate measurement of forest site productivity. Forest sites, particularly in open and degraded areas should be determined with direct method.

RELATIONSHIPS BETWEEN SITE INDEX AND SOME EDAPHIC AND PHYSOGRAPHIC FACTORS OF PURE ORIENTAL SPRUCE (Picea orientalis Link.) IN ARTVİN GENYA MOUNTAIN

Bu arastirma Artvin Orman Bolge Mudurlugu, Artvin Orman Isletme Mudurlugu, Merkez Isletme Şefligi sinirlari icerisindeki Genya Dagi bolgesinde yayilis gosteren saf Dogu Ladini mescerelerinde bonitet endeksi ile bazi edafik ve fizyografik ozellikler arasindaki iliskilerin saptanabilmesi amaciyla gerceklestirilmistir. Bu amacla Genya Dagi bolgesinde saf olarak yayilis gosteren Dogu Ladini mescerelerinden 50 tane deneme alani secilmis, her bir deneme alanina iliskin fizyografik ve edafik ozellikler belirlenmistir. Topraga iliskin ozelliklerin belirlenebilmesi icin toprak profilleri acilmis ve ornekler alinmistir. Ayrica her bir deneme alaninda mescerelerin bonitet endeksi (100 yasindaki ust boy) belirlenmistir. Mescere bonitet endeksi ile edafik ve fizyografik faktorler arasindaki iliskiler korelasyon analizi ile sorgulanmistir. Bu ekolojik etmenlerden egim, fizyolojik toprak derinligi, mutlak toprak derinligi, Ah ve B horizonundaki kil ve kum miktarilari (%) ile bonitet endeksi arasinda onemli ve anlamli iliskiler bulunmustur. Anahtar Kelimeler: Dogu Ladini, Bonitet Endeksi, Edafik Faktor, Fizyografik Faktor, Artvin.

Effects of afforestation on microbial biomass C and respiration in eroded soils of Turkey

ABSTRACT Soil erosion is a major socioeconomic and environmental problem in Turkey. Almost 86% of the land in Turkey has suffered various degrees of soil erosion. The objective of this study was to determine whether differences in tree species affect soil characteristics and microbial activity in degraded soils. Results from this study showed that organic C (Corg) was highest in the black locust soil at 0–20 cm depth and lowest in the bare land. Microbial biomass C (Cmic) increased in the order black locust > Scotch pine > bare land at two soil depths. One-way ANOVA demonstrated that afforested soils contain significantly higher microbial biomass C than those in the bare land soils. Microbial quotient (Cmic/Corg) of soils are positively influenced by afforestation as the bare land soils exhibited lower microbial quotient than the associated Scotch pine and black locust soils. Microbial communities in black locust soils were energetically more efficient—had a lower metabolic quotient (qCO2)—with a higher Cmic/Corg compared to those in Scotch pine soils. However, the microbial quotient in our study was still below range and cannot reach equilibrium again 15 yr after afforestation. Restoration of degraded lands could be a long-term process from microbial activity in the observed regions.

Determination of stand structure in even-aged Oriental Beech Forests in Turkey

Este estudio tuvo como objetivo desarrollar un modelo de rendimiento de rodales para bosques puros y uniforme de Fagus orientalis en la provincia de Sinop, norte de Turquia. Los datos se obtuvieron de 238 parcelas de muestreo de rodales con edad de 24-131 anos, indice de sitio de 19,0-35,9 m e indice de densidad relativo de 2,2-10,8. Con sistemas de ecuaciones generadas fueron determinados numericamente la edad del rodal, el indice de sitio y la densidad de los rodales, incluyendo la determinacion numerica de los efectos de las interacciones de los factores individuales, dobles y triples. En los rodales coetaneos, el aumento principal de los valores dependio de la edad, el indice de sitio y la densidad. La cantidad de tallos por hectarea disminuyo a medida que el rodal envejecia y el indice de sitio aumentaba; la cantidad, sin embargo, aumento en paralelo con la densidad del rodal. El incremento de volumen anual actual alcanzo un pico a los 30-35 anos en todos los grupos de indice de sitio y de niveles de densidad, y comenzo a caer despues. El incremento anual del volumen medio escala su pico a los 65-75 anos en todas las clases de indice de sitio y niveles de densidad, antes de comenzar a disminuir. Los resultados se encontraron de acuerdo con las normas reconocidas de crecimiento. El modelo de rendimiento de rodales se evaluo como tabla de rendimiento de variable de densidad utilizada para la estimacion de los rodales restantes, eliminados y totales