| Title | Long-term interactions between Mediterranean climate, vegetation and fire regime at Lago di Massaciuccoli (Tuscany, Italy) |
| Abstract | 1
A Holocene sedimentary sequence from a coastal lake in the Mediterranean area
(Lago di Massaciuccoli, Tuscany, Italy, 0 m a.s.l.) was sampled for pollen and
microscopic charcoal analyses. Contiguous 1-cm samples represent an estimated time
interval of
c.
13 years, thus providing a high-resolution sequence from 6100 to 5400 cal.
years
??
.
2
Just before 6000 cal. years
??
, sub-Mediterranean and Mediterranean forests were
present together with fir (
Abies alba
), a submontane species that is today absent at low
altitudes in the Mediterranean. A sharp vegetational change occurred after 6000 cal.
years
??
involving a drastic decline of
Abies alba
around the site.
3
Time-series analyses suggest that increased fire activity at this time caused a strong
decline in
Abies alba
, a highly fire-sensitive species. During 100 years of higher fire
incidence, diverse (predominantly evergreen) forest communities were converted to
low-diversity fire-prone shrub communities.
4
Cross-correlations reveal that fire during the mid-Holocene hindered the expansion
of holm oak (
Quercus ilex
), the most common tree species today in Mediterranean environments.
While the factors that triggered the Holocene expansion of this species in the
Mediterranean area are unclear, our results do not support the hypothesis that fire was
key for holm oak expansion.
5
Diatom analyses of the same sediment core provide an independent palaeoenvironmental
proxy for palaeoclimatic reconstruction. A change in the eutrophy and salinity
of the lake occurred just before 6000 cal. years
??
, suggesting that a climatic shift towards
aridity may have triggered the observed change in hydrology and possibly also in fire
regime.
6
Over the millennia fire has decisively contributed to the establishment of the present
fire-adapted vegetation type (macchia). Native fire-sensitive species were displaced or
repressed, and arboreal vegetation became less diverse. Combined ecological and
palaeoecological data may help to assess possible future scenarios of biosphere
responses to global change. Our results imply that the forecasted global warming and
fire increase may trigger irrecoverable biodiversity losses and shifts in vegetational
composition within a few decades or centuries at most. In particular, fire and droughtsensitive
vegetation types, such as the relict forests of
Abies alba
in the Apennines, seem
particularly threatened by large-scale displacement. |
| Source | Journal of ecology (Print) 95, pp. 755–770 |
| Keywords | Long-term interactionsMediterranean climatevegetationfire regimeMassaciuccoli |
| Journal | Journal of ecology (Print) |
| Editor | Blackwell Scientific Publications., Oxford, Regno Unito |
| Year | 2007 |
| Type | Articolo in rivista |
| DOI | 10.1111/j.1365-2745.2007.01240.x |
| Authors | Colombaroli D.(1), Marchetto A., Tinner W.(1) |
| Text | 52988 2007 10.1111/j.1365 2745.2007.01240.x ISI Web of Science WOS 000247320100018 Long term interactions Mediterranean climate vegetation fire regime Massaciuccoli Long term interactions between Mediterranean climate, vegetation and fire regime at Lago di Massaciuccoli Tuscany, Italy Colombaroli D. 1 , Marchetto A., Tinner W. 1 1 Dipartimento di Biologia Vegetale, Universita di Berna, Svizzera 1 A Holocene sedimentary sequence from a coastal lake in the Mediterranean area Lago di Massaciuccoli, Tuscany, Italy, 0 m a.s.l. was sampled for pollen and microscopic charcoal analyses. Contiguous 1 cm samples represent an estimated time interval of c. 13 years, thus providing a high resolution sequence from 6100 to 5400 cal. years . 2 Just before 6000 cal. years , sub Mediterranean and Mediterranean forests were present together with fir Abies alba , a submontane species that is today absent at low altitudes in the Mediterranean. A sharp vegetational change occurred after 6000 cal. years involving a drastic decline of Abies alba around the site. 3 Time series analyses suggest that increased fire activity at this time caused a strong decline in Abies alba , a highly fire sensitive species. During 100 years of higher fire incidence, diverse predominantly evergreen forest communities were converted to low diversity fire prone shrub communities. 4 Cross correlations reveal that fire during the mid Holocene hindered the expansion of holm oak Quercus ilex , the most common tree species today in Mediterranean environments. While the factors that triggered the Holocene expansion of this species in the Mediterranean area are unclear, our results do not support the hypothesis that fire was key for holm oak expansion. 5 Diatom analyses of the same sediment core provide an independent palaeoenvironmental proxy for palaeoclimatic reconstruction. A change in the eutrophy and salinity of the lake occurred just before 6000 cal. years , suggesting that a climatic shift towards aridity may have triggered the observed change in hydrology and possibly also in fire regime. 6 Over the millennia fire has decisively contributed to the establishment of the present fire adapted vegetation type macchia . Native fire sensitive species were displaced or repressed, and arboreal vegetation became less diverse. Combined ecological and palaeoecological data may help to assess possible future scenarios of biosphere responses to global change. Our results imply that the forecasted global warming and fire increase may trigger irrecoverable biodiversity losses and shifts in vegetational composition within a few decades or centuries at most. In particular, fire and droughtsensitive vegetation types, such as the relict forests of Abies alba in the Apennines, seem particularly threatened by large scale displacement. 95 articolo pubblicato 01_JoE_2007.pdf Articolo in rivista Blackwell Scientific Publications. 0022 0477 Journal of ecology Print Journal of ecology Print J. ecol. Print aldo.marchetto MARCHETTO ALDO TA.P02.005.002 Uso della paleolimnologia come strumento per lo studio del paleoclima e dell evoluzione climatica |
