Understorey vegetation is a key component of plant biodiversity in forests. Events of extreme drought are a potential major driver of change of this layer. Although these are predicted to increase in frequency and duration due to climate change, their impacts on understorey communities are still unknown. In this paper, we re-surveyed a set of 36 plots in mature thermophilous deciduous forests eight months after the end of an extremely dry period in 2016-2017. The plots are part of a European network representing a gradient of overstorey richness from 1- to 5-tree species mixtures, with variable composition. We took advantage of this model system to test the hypothesis that species richness and identity of dominant trees in the overstorey may modulate the impact of drought on understorey cover, diversity and composition. In spring 2018, a ca. 50% reduction of understorey cover occurred in both mono-specific and mixed plots. Species evenness and Shannon α-diversity increased in the monospecific plots, due to a reduction of abundance of tree species at juvenile stage and the appearance of non-forest specialists that did not occur in the mixtures. Overstorey species identity effects on understorey diversity were negligible. Overall compositional changes were moderate, though larger in the mixed plots and in those with the less drought-adapted tree species in the overstorey. Ellenberg ecological profile of the community did not change significantly but light values tended to increase in the monospecific plots, contrary to the mixtures. Overall, our findings provide circumstantial support to a higher diversity stability in the understorey of mixed plots shortly after drought, despite compositional variations. More studies and monitoring programs are needed to assess understorey recovery capacity and resilience after such events in the long-term.

Understorey changes after an extreme drought event are modulated by overstorey tree species mixtures in thermophilous deciduous forests / Giovanni Iacopetti, Filippo Bussotti, Elisa Carrari, Federico Selvi. - In: FOREST ECOLOGY AND MANAGEMENT. - ISSN 0378-1127. - STAMPA. - 484:(2021), pp. 1-11. [10.1016/j.foreco.2021.118931]

Understorey changes after an extreme drought event are modulated by overstorey tree species mixtures in thermophilous deciduous forests

Giovanni Iacopetti;Filippo Bussotti;Elisa Carrari
;
Federico Selvi
2021

Abstract

Understorey vegetation is a key component of plant biodiversity in forests. Events of extreme drought are a potential major driver of change of this layer. Although these are predicted to increase in frequency and duration due to climate change, their impacts on understorey communities are still unknown. In this paper, we re-surveyed a set of 36 plots in mature thermophilous deciduous forests eight months after the end of an extremely dry period in 2016-2017. The plots are part of a European network representing a gradient of overstorey richness from 1- to 5-tree species mixtures, with variable composition. We took advantage of this model system to test the hypothesis that species richness and identity of dominant trees in the overstorey may modulate the impact of drought on understorey cover, diversity and composition. In spring 2018, a ca. 50% reduction of understorey cover occurred in both mono-specific and mixed plots. Species evenness and Shannon α-diversity increased in the monospecific plots, due to a reduction of abundance of tree species at juvenile stage and the appearance of non-forest specialists that did not occur in the mixtures. Overstorey species identity effects on understorey diversity were negligible. Overall compositional changes were moderate, though larger in the mixed plots and in those with the less drought-adapted tree species in the overstorey. Ellenberg ecological profile of the community did not change significantly but light values tended to increase in the monospecific plots, contrary to the mixtures. Overall, our findings provide circumstantial support to a higher diversity stability in the understorey of mixed plots shortly after drought, despite compositional variations. More studies and monitoring programs are needed to assess understorey recovery capacity and resilience after such events in the long-term.
2021
484
1
11
Goal 15: Life on land
Giovanni Iacopetti, Filippo Bussotti, Elisa Carrari, Federico Selvi
File in questo prodotto:
File Dimensione Formato  
Iacopetti et al. ForEco2021.pdf

accesso aperto

Descrizione: pdf editoriale versione elettronica Jan 2021
Tipologia: Pdf editoriale (Version of record)
Licenza: DRM non definito
Dimensione 3.3 MB
Formato Adobe PDF
3.3 MB Adobe PDF

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/1220399
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 4
  • ???jsp.display-item.citation.isi??? 1
social impact