Assessing Crop Yield Sustainability under the Climatic and Bioclimatic Change in the Area of Palestine

We analyzed plant production such as olive, grape and fig in several Palestinian Occupied Territories, and studied the correlation analyses between productions and climatic, bioclimatic features in the territory. This work examines the following climate factors: average temperature, precipitation, soil water reserve and water deficit;and bioclimatic parameters such as compensated thermicity index, ombrothermic index and continentally index. The data used were from nine meteorological stations of the Palestinian Meteorological Department. The study was based on the correlation analyses between olive, grape and fig production in nine plots: Hebron, Ramallah, Nablus, Jenin, Jericho, Bethlehem, Jerusalem and Tulkarem over fourteen years. The analysis of variance revealed a significant influence of the variables temperature and compensated thermicity index on the production of olive and fig, and a low influence on grape production. When we applied canonical correspondence analysis (CCA), the Nablus, Jenin, Jericho and Gaza plots were most affected by the climate factors as temperature, and bioclimate factors as compensated thermicity index, whereas, the Hebron, Bethlehem, Jerusalem, Tulkarem and Ramallah plots showed the influence of ombrothermic index, continentally index, precipitation, water deficit and soil water reserve.

Case Study: Analysis of the Physical Factors of Palestinian Bioclimate

This study analyses the physical factors of the Palestinian bioclimate, the mean monthly and annual temperature, mean monthly maximum temperature, and mean monthly minimum temperature using data from six weather stations from the Palestine Meteorological Department, recorded in two periods: The first period from 1969 to 1981, the second period from 1975 to 1995 (more than 32 years). Statistical tests included a bioclimatic analysis of Palestinian meteorological stations for the periods from 1969-1981 and 1975-1995 by using bioclimatic classification of the Earth of Rivas Martinez Salvador, with regard to thermicity index, compensated thermicity index, annual ombrothermic index, and simple continentality index. The bioclimate of Palestineis affected by various factors, such as the Jordanian-Syrian desert, and its natural geography and topography, among others as well as biodiversity. Annual ombrothermic index value ranging between 0.6 to 3.4 and simple continentality index was from 12.4 to 18.1. It is concluded that the occupied Palestinian territories belong to the arid, semiarid, dry, sub-humid and humid ombrotype, and the Inframediterranean, Thermomediterranean and Mesomediterranean bioclimatic belt.

Bioclimate-Vegetation Interrelations along the Pacific Rim of North America

This study was designed to examine relationships between climate and vegetation of the Pacific rim of North America, from the Mediterranean deserts of California to Alaska’s boreal taiga. Relations were inferred from temperature and rainfall data recorded at 457 weather stations and by sampling the vegetation around these stations. Climate data were used to construct climatograms, calculate forty one variables and detect main latitudinal and longitudinal gradients. In order to identify the best functions able to relate our variables, polynomial and non-polynomial regressions were performed. The k-means algorithm was the clustering method used to validate the variables that could best support our bioclimatic classification. The variable that best fitted our classification was finally used to prepare a discriminatory key for bioclimates. Across this extensive area three macrobioclimates were identified, Mediterranean, Temperate and Bo- real, within which we were able to distinguish nine bioclimates. Finally, we relate the different types of potential natural vegetation to each of these bioclimates and describe their floristic composition and physiognomy.