Associação de organismos epifíticos e seu efeito sobre o ciclo da água no nível ecossistêmico: discutindo o conceito do holobionte na ecohidrologia

Abstract

Vascular plants are the main target of studies involving the global water cycle and its ecosystem processes, such as the interception of rainfall, runoff through branches and trunks (stemflow), drip to the ground (throughfall), and the return to the atmosphere from evaporation. However, little is known about the combined effect between vegetation and the living beings associated with them, such between lichens, bryophytes and vascular plants. This extended phenotype of the sum of characteristics of host plants and their associated biota, the so-called holobiont, has recently come to be recognized as the unit of both an individual's response to environmental factors and its effect on ecological processes, since this integration determines the interface of interaction of the organism with the environment. Considering that the whole can be greater than the sum of the parts, this work aims to discuss the ecohydrological effect of this set of species that make up the holobiont, that is, the sum of the functional characteristics of the entire epiphytic community found on the vegetation together with the characteristics of the host plant and its contribution to the water cycle at an ecosystem level. For this, a systematic review was carried out in order to understand the current knowledge state, discuss possible knowledge gaps and the need for further studies in light of the current climate emergency scenario. As a result of the selected articles, an intimate relationship was found between epiphytic beings and their hydrological effect at the ecosystem level, such as the maintenance of temperature and humidity, as well as in the water flow capacity. Understanding this interrelation is of vital importance for environments with large coverage of epiphytes such as Tropical, Cloud and Amazon Forests, since these have been directly suffering the consequences of anthropic impacts, which can have consequences for the global water cycle.