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Diffusional limitations to photosynthesis, relative water content (RWC), pigment concentrations and their association with reflectance indices were studied in olive (Olea europaea) saplings subjected to water-stress and re-watering. RWC decreased sharply as drought progressed. Following rewatering, RWC gradually increased to pre-stress values. Photosynthesis (A), stomatal conductance (g(s)), mesophyll conductance (g(m)), total conductance (g(t)), photochemical reflectance index (PRI), water index (WI) and relative depth index (RDI) closely followed RWC. In contrast, carotenoid concentration, the carotenoid to chlorophyll ratio, water content reflectance index (WCRI) and structural independent pigment index (SIPI) showed an opposite trend to that of RWC. Photosynthesis scaled linearly with leaf conductance to CO2; however, A measured under non-photorespiratory conditions (A(1%O2)) was approximately two times greater than A measured at 21% [O-2], indicating that photorespiration likely increased in response to drought. A(1%O2) also significantly correlated with leaf conductance parameters. These relationships were apparent in saturation type curves, indicating that under non-photorespiratory conditions, CO2 conductance was not the major limitations to A. PRI was significant correlated with RWC. PRI was also very sensitive to pigment concentrations and photosynthesis, and significantly tracked all CO2 conductance parameters. WI, RDI and WCRI were all significantly correlated with RWC, and most notably to leaf transpiration. Overall, PRI correlated more closely with carotenoid concentration than SIPI; whereas WI tracked leaf transpiration more effectively than RDI and WCRI. This study clearly demonstrates that PRI and WI can be used for the fast detection of physiological traits of olive trees subjected to water-stress.

Abstract While soils are as essential to human society as air and water, soil degradation has not received nearly as much attention as the threats to these other elements. On the map of water erosion of Europe, Southern Europe is red “colored”. Erosion in the Balkan countries, through both on and offsite effects is a major cause of soil and water degradation. This paper compares erosion control works in several countries from the Balkan region (Macedonia, Serbia, and Bulgaria). The basis for comparative analyses was various country reports as well as available published papers. Quantitative method-text analyze method was used for these study. Natural conditions in the Balkan countries contribute to the appearance of various erosion forms and the intensity of the erosion processes. Over the history of these countries, people who settled this region used the available natural resources to fill their needs (tree cutting, incorrect plugging, overgrazing), which contributed to soil erosion. Organized erosion control works in the Balkans started in the beginning of the 20th century (1905 in Bulgaria). The highest intensity of erosion control works were carried out during the period 1945 – 1990. Various erosion control works were launched. Bulgaria had a large anti-erosion afforestation, almost 1 million ha. Bulgaria's ecological river restoration approach has been in use for almost 50 years. Serbia contributed significant erosion and torrent control works on hilly agricultural areas. Specific screen barrages and afforestation on extremely dry areas are characteristic in Macedonia. A common characteristic for all countries is a high decrease in erosion control works in the last 20 years.

Forcing mechanisms for sea level variability in the Black Sea are investigated in the context of an observed increase in the sea level of this basin by 2.5 mm/yr over the last 60 years. Temperature and salinity variations computed from the Mediterranean Data Archeology and Rescue (MEDAR) data set exhibit significant interdecadal variability. However, the corresponding steric height variation does not show a long‐term increase and thus cannot account for the observed change in sea level. The impact of surface freshwater flux (P‐E) changes is also investigated using two independent data sets. The first data set, which is based on measurements collected in the basin, can explain most of the sea level variability, with only 0.8 mm/yr remaining unexplained. The second data set, output from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis, is unable to explain any of the observed trend. Potential contributions from changes in river runoff and surface pressure are quantified but found to be minor terms. By comparing the observed salinity changes with the sea level rise and the P‐E variability in the first data set, we infer that the P‐E variations are the primary cause for the observed sea level rise, while land movements are likely to partly contribute, too. The relationship of Black Sea temperature and salinity variability with corresponding variability in the connected Aegean Sea has also been explored. A significant correlation is found between the salinity of the upper water of the Aegean Sea and the layer between 50 and 300 m in the Black Sea, indicating that the latter layer is a product of the Mediterranean inflow.