Advisor(s)
Abstract(s)
Climate changes comprise increasing global temperature and water cycle deregulation (precipitation storms and
long dry seasons). Many affected ecosystems are located within the Mediterranean basin, where cork oak
(Quercus suber L.) is one of the most important forest ecosystems. Despite cork oak tolerance to drought, the
decrease of water availability and increase of temperature is causing a serious decline of cork oak populations. In
the present work, the bacterial community of cork oak soils was assessed by metabarcoding using Illumina Miseq.
Soils from seven independent cork oak forests were collected along a climate gradient. In all forest soils,
Proteobacteria and Actinobacteria were the richest and more abundant bacteria. Acidobacteria also presented a
high relative abundance, and Chloroflexi was a rich phylum. The soil bacterial community diversity and composition
was strongly affected by the climatic region where cork oak resides and specific bacterial taxa were
differently affected by precipitation and temperature. Accordingly, cork oak bacterial communities clustered
into three distinct groups, related with humid, sub-humid and arid/semi-arid climates. Driest and warmer forests
presented more diverse bacterial communities than humid and coolest forests. However, driest climates presented
more homogenous bacterial communities among forests than humid climates. Climate (mainly precipitation)
revealed to be the strongest driver leading to significant variations of bacterial community profiles.
The most impacted bacterial taxa by climatic variables were Proteobacteria, in particular Gammaproteobacteria
and Deltaproteobacteria, Chloroflexi, and Firmicutes. Humid forests presented mainly Acidobacteria as good indicators
of climate, whereas Actinobacteria members were better indicators for arid forests (mainly Gaiellales and
Frankiales). Some indicator species for different climate conditions were members of the bacterial core of cork
oak stands (7% of the total bacterial community). Taken together, different microbiomes were selected by the
climate conditions in cork oak stands along a climate gradient and might provide the key to forest sustainability
in times of global warming.
Description
Keywords
Bacterial communities Climate Cork oak Forest soils
Citation
Reis, Francisca; Soares-Castro, Pedro; Costa, Daniela; Tavares, Rui M.; Baptista, Paula; Santos, Pedro M.; Lino-Neto, Teresa (2019). Climatic impacts on the bacterial community profiles of cork oak soils. Applied Soil Ecology. ISSN 0929-1393. 143, p. 89-97