Ecological examination of intra-annual and altitudinal variation of leaf area index (LAI) values for the forest ecosystem within the reservoir landscape of Bartın-Kirazlıköprü dam

Bartın-Kirazlıköprü dam watershed constitutes almost half of the Bartın Stream Watershed and is the source of a significant portion of the water coming from the entire watershed. The Ulus Stream and the Ovacuma Stream, which is included in the Ulus Stream in Abdipaşa Town, and their other tributaries feed the Gökırmak Stream, which then feeds the Bartın-Kirazlıköprü dam reservoir. A mixed stand consisting of various deciduous tree species located in the forest ecosystem within the reservoir area of Kirazlıköprü dam was chosen as the sampling area of this thesis study. With this study, we aimed to reveal the spatial and temporal changes of the dam landscape at a certain level by observing this stand within the landscape of the dam reservoir area, depending on the altitude and throughout a year. Thus, the basis will be laid for sustainable forest landscape management and indicators of the health of the relevant ecosystem, depending upon the ecological characteristics of the vegetation of the area. In line with these aims and objectives, within the framework of our study subject, depending on the altitude, inra-annual determination of principally the Leaf Area Index (LAI), then Light Transmission (LT), Gap Fraction (GF) and Canopy Openness (CO) the parameters, which are among the vegetation canopy indicators, is primarily targeted. By recording the obtained data and values, it is aimed to express and present them more clearly with relevant graphics and visuals. A total of 21 field studies were carried out between March 2021 and February 2022 throughout a one-year period beneath the on the canopies of the deciduous trees. Thus, the monitoring and analysess of the vegetation canopy change of the forest ecosystem in the landscape were carried out. As a matter of fact, while the LAI2200C produced on-site analysis results, the data obtained from the hemisphere photographs were later analysed with Hemisphere 3.1 software (Swiss Federal Institute for Forest, Snow and Landscape Research), which is capable of image processing. These hemispherical photographs were taken using a Sigma 8 mm fisheye lens (Sigma F3.5 EX DG Circular Fisheye-Sigma Corporation) mounted on a Canon EOS 5D Mark II SLR camera. As a result, the intra-annual values and models of the tree canopy parameters followed a very similar overlapping or symmetrical course with the intra-annual air-soil temperature values and models, but the same situation, nominately a similar overlap with the precipitation values and model, did not occur.As a matter of fact, high and significant positive or negative correlations between tree canopy parameters and air-soil temperature data confirmed these similarities. One of the important results of this study was to reveal the determining role of air-soil temperature values on the canopy parameters, especially at the turning points of the seasons and, accordingly, the phenological periods of the trees. With this study, it has been understood that these possible phenological and eco-physiological variations due to climate during the transitions between the dormancy and growing seasons of the trees, especially in the forest areas, that compose the dam reservoir landscape, may directly or indirectly affect the photosynthesis of the trees and therefore the productivity of the entire forest ecosystem within the reservoir landscape. As a result, this study has managed to reveal the vegetation canopy parameter values and data together with meteorological parameter values and data in order to affect the ecosystem of an artificial lake landscape formed behind the man-made dam and the healthy sustainability of this ecosystem. On the other hand, the results of this study provide important indicators to reveal the importance of tree canopies within the framework of landscape ecology, their effects on the structure and functionality of ecosystems, and even their landscape value, taking into account seasonal and inter-seasonal transition and changes in the altitudinal gradients. It is undeniable that the parameters of LT, GF and CO, especially the LAI, can contribute to the development and taking of scientifically based and consistent ecological decisions by using them in many study fields of landscape ecology such as landscaping, ecosystem management, biodiversity protection and ecosystem services. The findings of this study also emphasize that the vegetation canopy parameters are a valuable tool in sustainable management of natural resources and environmental protection efforts and, are an important indicator for the protection of ecosystem health and diversity.