RICCARDO TESTOLIN

Dottore di ricerca

ciclo: XXXIII



Titolo della tesi: Macroecology of global alpine vegetation

Alpine ecosystems, namely high-elevation habitats above the climatic treeline, are essential to human livelihoods and are among the environments with the highest vulnerability to anthropogenic climate change. Despite the overall agreement on the distribution and ecological features of terrestrial biomes, the actual extent and bioclimatic characteristics of alpine ecosystems worldwide are still uncertain. Furthermore, the patterns and drivers of plant diversity and functioning in alpine ecosystems are largely unknown at the global scale. This work represents an important contribution to the delineation of macroecological patterns of global alpine biomes. First, I created a map of global alpine areas by modelling regional treeline elevations at high spatial resolution using global forest cover data. I used this map in combination with global digital datasets to assess the climatic characteristics of alpine ecosystems and to evaluate patterns of primary productivity. Second, I assessed the global patterns of plant species richness in alpine ecosystems and the relative effect of environmental, geographical and historical factors at different spatial scales. To do so, I compiled a global dataset of alpine vegetation consisting of more than 8,900 plots, evaluated latitudinal patterns of regional and community richness and modelled them against different predictors estimated using global raster layers. Third, I assessed the functional variation of alpine vegetation and its relationship with evolutionary history and macroclimate. I filtered the abovementioned dataset of alpine vegetation plots based on the availability of functional trait and phylogenetic data. I assessed the functional trade-offs of alpine plant species and the functional dissimilarity of alpine vegetation across large geographic units with different dominant lowland vegetation, macroclimate, and evolutionary history. Finally, I modelled functional dissimilarity against environmental and phylogenetic dissimilarity. I found that alpine biomes cover almost 3% of land outside Antarctica. Despite temperature differences across latitudes, these ecosystems converge below a sharp threshold of 5.9 °C and towards the colder end of the global climatic space. Below that temperature threshold, alpine ecosystems are influenced by a latitudinal gradient of mean annual temperature and are climatically differentiated by seasonality and continentality. This gradient delineates a climatic envelope of global alpine biomes. Although alpine biomes are similarly dominated by poorly vegetated areas, world ecoregions show strong differences in the productivity of their alpine belt irrespectively of major climate zones. Furthermore, in contrast with the well-known latitudinal diversity gradient, plant species richness of some temperate alpine regions in Eurasia is comparable to that of hyper-diverse tropical alpine ecosystems. This pattern is mainly explained by the current and past alpine area, isolation, and variation in soil pH among regions, while community richness depends on local environmental factors. Finally, plant species in alpine areas seemingly reflect the global variation of plant function and are mainly differentiated for their resource-use strategies. The current macroclimate exerts a limited effect on alpine vegetation, mostly acting at the community level in combination with evolutionary history. Alpine vegetation is also functionally independent from the vegetation zones in which it is embedded, exhibiting strong functional convergence at the global scale. Overall, despite their global distribution and apparent heterogeneity, alpine environments form a distinct group of functionally convergent biomes, strongly decoupled from lowland environments, and with a varied biogeographic history, whose legacy can still be observed on current diversity patterns which are locally refined by fine-scale factors.

Produzione scientifica

11573/1661220 - 2021 - Citizen science data to measure human use of green areas and forests in european cities
Cambria, Vito Emanuele; Campagnaro, Thomas; Trentanovi, Giovanni; Testolin, Riccardo; Attorre, Fabio; Sitzia, Tommaso - 01a Articolo in rivista
rivista: FORESTS (Basel, Switzerland : MDPI Publishing) pp. - - issn: 1999-4907 - wos: WOS:000666247700001 (8) - scopus: 2-s2.0-85108641512 (11)

11573/1530516 - 2021 - Global patterns and drivers of alpine plant species richness
Testolin, Riccardo; Attorre, Fabio; Borchardt, Peter; Brand, Robert F.; Bruelheide, Helge; Chytrý, Milan; De Sanctis, Michele; Dolezal, Jiri; Finckh, Manfred; Haider, Sylvia; Hemp, Andreas; Jandt, Ute; Kessler, Michael; Korolyuk, Andrey Yu; Lenoir, Jonathan; Makunina, Natalia; Malanson, George P.; Montesinos‐Tubée, Daniel B.; Noroozi, Jalil; Nowak, Arkadiusz; Peet, Robert K.; Peyre, Gwendolyn; Sabatini, Francesco Maria; Šibík, Jozef; Sklenář, Petr; Sylvester, Steven P.; Vassilev, Kiril; Virtanen, Risto; Willner, Wolfgang; Wiser, Susan K.; Zibzeev, Evgeny G.; Jiménez‐Alfaro, Borja - 01a Articolo in rivista
rivista: GLOBAL ECOLOGY AND BIOGEOGRAPHY (Blackwell Science Limited:PO Box 88, Oxford OX2 0NE United Kingdom:011 44 1865 776868, 011 44 1865 206038, EMAIL: journals.cs@blacksci.co.uk, INTERNET: http://www.blackwell-science.com, Fax: 011 44 1865 721205) pp. 1-14 - issn: 1466-822X - wos: WOS:000635352800001 (45) - scopus: 2-s2.0-85103416429 (49)

11573/1408820 - 2020 - Global distribution and bioclimatic characterization of alpine biomes
Testolin, Riccardo; Attorre, Fabio; Jiménez‐Alfaro, Borja - 01a Articolo in rivista
rivista: ECOGRAPHY (Blackwell Munksgaard:PO Box 2148, Periodicals Department, DK-1016 Copenhagen K Denmark:011 45 33 755913, EMAIL: agentservices@oxon.blackwellpublishing.com, INTERNET: http://www.blackwellmunksgaard.com, Fax: 011 45 77 333377) pp. 779-788 - issn: 0906-7590 - wos: WOS:000516869800001 (47) - scopus: 2-s2.0-85080122021 (60)

11573/1090600 - 2018 - An innovative approach to disentangling the effect of management and environment on tree cover and density of protected areas in African savanna
Messina, Mario; Cunliffe, Robert; Farcomeni, Alessio; Malatesta, Luca; Smit, Izak P. J.; Testolin, Riccardo; Ribeiro, Natasha S.; Nhancale, Bruno; Vitale, Marcello; Attorre, Fabio - 01a Articolo in rivista
rivista: FOREST ECOLOGY AND MANAGEMENT (Elsevier BV:PO Box 211, 1000 AE Amsterdam Netherlands:011 31 20 4853757, 011 31 20 4853642, 011 31 20 4853641, EMAIL: nlinfo-f@elsevier.nl, INTERNET: http://www.elsevier.nl, Fax: 011 31 20 4853598) pp. 1-9 - issn: 0378-1127 - wos: WOS:000432498900001 (5) - scopus: 2-s2.0-85044150518 (5)

11573/1207001 - 2016 - Optimum plot and sample sizes for carbon stock and biodiversity estimation in the lowland tropical forests of Papua New Guinea
Grussu, Giorgio; Testolin, Riccardo; Saulei, Simon; Farcomeni, Alessio; Yosi, Cossey K.; De Sanctis, Michele; Attorre, Fabio - 01a Articolo in rivista
rivista: FORESTRY (Oxford University Press:Journals Department, Great Clarendon Street, Oxford OX2 6DP United Kingdom:011 44 1865 556767, EMAIL: jnlorders@oup.co.uk, INTERNET: http://www.oup.co.uk, Fax: 011 44 1865 267485) pp. 150-158 - issn: 0015-752X - wos: WOS:000370970000005 (16) - scopus: 2-s2.0-84964714890 (16)

11573/854832 - 2016 - Investigating the effect of selective logging on tree biodiversity and structure of the tropical forests of Papua New Guinea
Testolin, Riccardo; Saulei, Simon; Farcomeni, Alessio; Grussu, Giorgio; Yosi, Cossey; De Sanctis, Michele; Attorre, Fabio - 01a Articolo in rivista
rivista: IFOREST (Viterbo : SISEF) pp. 475-482 - issn: 1971-7458 - wos: WOS:000378211100001 (5) - scopus: 2-s2.0-84970939138 (6)

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