Effect of hybridization in the firs: artificial hybridization may lead to higher survival rate

Hybridization experiments among fir (Abies) species contribute to clarification of both crossability and evolutionary relationships of organisms at least from the second half of the nineteenth century. The main aim of our study was to find possible effects of hybridization on survival rate and two growth parameters (height and diameter at the breast height) of fir trees at various levels of complexity in the Czech Republic. We compared (1) pure species consisting of seven fir taxa, (2) open pollinated hybrids comprising of twenty-one hybrid progenies of Greek Fir (A. cephalonica), Cilician Fir (A. cilicica) and Algerian Fir (A. numidica) and (3) artificial complex hybrids of Korean Fir (A. koreana) x (A. cilicica x A. cephalonica). For our analyses, we used combination of so-called traditional statistical methods and spatial modelling. Our results revealed that a higher level of hybridization and introgression may lead to a higher survival rate and furthermore, that neglecting of spatial autocorrelation in randomized complete block design might lead to wrong conclusions-because our analyses on height showed contrasting results between traditional and spatial modelling. The results of this study appear to be a good message for scientists dealing with forest tree breeding and facing a lack of confidence by practice. They might be also a good news for forestry practice, where foresters face high mortality during afforestation, e.g. in extreme environmental conditions. Our study highlighted that neglecting spatial autocorrelation could possibly lead to wrong conclusions in studies of similar spatial scale level.