Ancient introgression between distantly related white oaks (Quercus sect Quercus) shows evidence of climate-associated asymmetric gene exchange

Ancient introgression can be an important source of genetic variation that shapes the evolution and diversification of many taxa. Here, we estimate the timing, direction and extent of gene flow between two distantly related oak species in the same section (Quercus sect. Quercus). We estimated these demographic events using genotyping by sequencing data (GBS), which generated 25,702 single nucleotide polymorphisms (SNPs) for 24 individuals of California scrub oak (Quercus berberidifolia) and 23 individuals of Engelmann oak (Q. engelmannii). We tested several scenarios involving gene flow between these species using the diffusion approximation-based population genetic inference framework and model-testing approach of the Python package DaDi. We found that the most likely demographic scenario includes a bottleneck in Q. engelmannii that coincides with asymmetric gene flow from Q. berberidifolia into Q. engelmannii. Given that the timing of this gene flow coincides with the advent of a Mediterranean-type climate in the California Floristic Province, we propose that changing precipitation patterns and seasonality may have favored the introgression of climate-associated genes from the endemic into the non-endemic California oak.

Economic Evaluation Air Pollution Removal and Oxygen Production based on I-Tree program for Atrush Forest/Kurdistan Region Of Iraq*

The objectives of this study are to testing the impacts of Atrush forests on the environment and oxygen production based on I-Tree program, function and management decisions that will improve human health and environmental quality. Human communities derive many essential benefits from natural ecosystems; these benefits represent important and familiar parts of the economy. What has been less appreciated up to this day is that natural ecosystems also perform fundamental life-support services without them human civilizations would cease to thrive. Evaluation of the vegetation structure, conducted during 2017. Data from 21 fields located were analyzed using the I-Tree Eco program. The most common species of trees are Pinus brutia (Turkish pine). Quercus aegilops (Ajo mountain scrub oak ), Plantanus orientalis (Oriental plane tree), Pistacia atlantica (Mt.atlas mastic tree) as well as shrubs Crataegus azarolus (Mediterranean Medlar), Junipours occidentalis (Western juniper), Prunus amygdalus (Almendro), Rhus coriaria (sumac spp), Nerium oleander (Oleander). Results show that the Pollution removal is ( 0.106 ton/year) referred ($280 /year) for sum of surveyed trees and shrubs in Atrush location, and oxygen production is (2 ton/year) .That means there are a effected role of trees on ecosystem in selected area.