Why deadwood may be as effective as soil for the growth of a new generation of fir in mountain forests

Abstract

Deadwood plays multiple important roles within forest ecosystems. In the context of climate change, more frequent disturbances (windbreaks, droughts, etc.) will increase the quantity of dead trees. Researching deadwood and its effects on the growth and regeneration of a new generation of trees is therefore justified. Our aim was to elucidate whether the decay of wood could be as beneficial as soil to the growth of young trees. We determined the degree of nutrition of silver fir seedlings growing on soil and deadwood, as well as the morphological features of the above- and belowground parts of seedlings developing on these substrates. The study confirmed our supposition that deadwood in the fifth decomposition distribution might be as effective a substrate for the growth of fir seedlings as soil. Besides aluminium content, no differences were detected in seedlings’ micro- and macronutrient content. Furthermore, we found that the deadwood contained much less aluminium than the soil, which translated into the content of this component in the needles. Our study shows that deadwood can prove a better substrate for the growth of simple seedlings compared to highly acidic soils, due to its resistance to aluminium toxicity. Lying logs of deadwood create a valuable microhabitat with favourable abiotic conditions, providing young seedlings with suitable growth conditions.