No abstract

Ecosystems use solar energy for self-organisation and cool themselves by exporting entropy to the atmosphere as heat. These energy transformations are achieved through evapotranspiration, with plants as 'heat valves'. In this study, the dissipative process is demonstrated at sites in the Czech Republic and Belgium, using landscape temperature data from thermovision and satellite images. While global warming is commonly attributed to atmospheric CO 2 , the research shows water vapour has a concentration two orders of magnitude higher than other greenhouse gases. It is critical that landscape management protects the hydrological cycle with its capacity for dissipation of incoming solar energy.

Since the 1990s, the territory of the Šumava National Park (Czech Republic) has faced significant changes in land cover, especially deforestation, in conjunction with several bark beetle disturbances and hurricane Kyrill in 2007. The aim of the study is to review the hydrological and climatic function of the forest and deforestation impacts on the landscape temperature. As a case study, surface temperature changes of the selected area of Šumava National Park from the satellite Landsat thermal data is presented from 1991 to 2016. At the sites with decayed forest, the surface temperature increased by 2-4°C. Images from ground temperature measurements illustrate extreme temperature differences (∼35°C) at locations where dead wood has not been removed; in the live forest, they are around 5°C. Further, we show the increase in air temperature is associated with the decay of forest stands, including snow melting. The duration of the permanent snow cover on the mountaintops with the growing forest in the last four years is, on average, 11 days longer than the areas with decayed forest. The results show that the increase in surface temperature in the large area causes changes in the local climate and hydrological regime. These changes may have a negative impact on the surrounding ecosystems, including the Šumava wetlands and peat bogs belonging to the Ramsar sites. 1. Forests promote precipitation. 2. Trees and forests are natural cooling systems. 3. Forests generate air and moisture flows. 4. Trees and forests can improve groundwater recharge. 5. Forests can moderate flooding. The authors bring evidence both from ecophysiological studies and from evaluation of how large forest complexes function. They emphasize the direct role of forests in the distribution of solar energy, cooling, water cycle, and local climate. The IPCC (Intergovernmental Panel on Climate Change) and mainstream science focus on the role of forests and wetlands in global climate change in terms of the greenhouse effect: forests affect climate by serving as a sink/source for carbon dioxide and other greenhouse gases (GHGs). Forests affect the climate positively through carbon dioxide

No abstract

No abstract

A decrease in total area of tropical forests is considered as a significant factor that influences landscape functioning, including the hydrological cycle; it contributes to climate change, and has many other consequences. This paper presents the extent of deforestation in Nakuru and Naivasha region (Rift Valley, Central Kenya) between the years 1986 and 2005 and its effects upon thermal characteristics of the landscape. Such changes have immense impact on hydrological regimes of the Rift Valley lakes in central Kenya. Multispectral data from Landsat TM, ETM + and Terra Aster were used to determinate dense and humid forests as well as their changes over time. A field observation, realized during the "dry" rainy season in October 2008, confirmed evident decline of precipitation and consequent low water discharge from the deforested catchment in the rivers and water level in lakes.

No abstract

No abstract