Roberta Pini

The Kyzylkum Desert of Uzbekistan preserves former branches of the Zerafshan River that once supported settlements such as the Late Bronze/Early Iron Age site of Kimirek-kum 1 (KK1). Here we reconstruct past ecosystems surrounding KK1 through multiproxy analysis of a stratified channel deposit, Trench H-2, that formed part of the site’s circular enclosure. The sequence was investigated using ¹⁴ C and OSL dating, sediment composition and grain-size analyses, and pollen, phytolith, macrobotanical, ostracod, and faunal data, supported by field observations of the local palaeochannel system. A Bayesian age–depth model constrains deposition within the channel to between ca. 1230 and 1030 ± 40 cal yrs BCE, contemporaneous with activity at KK1. During the earlier part of this interval (ca. 1230–1115 ± 40 cal yrs BCE), botanical proxies document a Tugai riparian forest of poplar, tamarisk, elm, alder, and reed sustained by local branches of the Zerafshan River. Ostracod assemblages indicate shallow freshwater conditions with abundant aquatic plants. Inhabitants of KK1 exploited local wood biomass as firewood, and practiced animal husbandry and crop cultivation. Around 1120–1110 ± 40 cal yrs BCE, a pronounced and rapid shift in plant assemblages, from woody riparian taxa to salt-tolerant shrubs and herbs, records a process of halophytization likely driven by altered river hydrology and declining groundwater. The ecological transition recorded in Trench H-2 corresponds to a phase of cooler and progressively more arid climatic conditions documented in regional palaeoclimatic records, suggesting that broad climatic forcing shaped local hydrologies and ecological response.

Sediments preserved in glacially overdeepened structures can provide a record of the regional Pleistocene glacial dynamics beyond the last glaciation. In order to unravel the glacial dynamics of the Isar-Loisach paleo-glacier, a cored sedimentary succession (ICDP-DOVE 5068_3_A) from an overdeepened basin near Schäftlarn, south of Munich, Germany, and an outcrop in its northern foreland (“Münchner Klettergarten” near Baierbrunn, on the southern margin of the Munich gravel plain, the “Münchner Schotterebene”) were investigated with a multi-method approach. This approach focused on single-grain feldspar luminescence dating to establish a chronological framework and on a comprehensive geophysical survey to better understand the morphology of the overdeepened basin. The Schäftlarn core is generally divided into a fine-grained basal section and a coarse-grained top section. The filling of the fine-grained basal section started in early Marine Isotope Stage (MIS) 8. The basal part of the overlying coarse-grained sediment can be attributed to late MIS 8. The “Münchner Klettergarten” outcrop to the north exhibited a similar depositional age dating to late MIS 8 and therefore corresponding to the basal part of the coarse-grained sediment in Schäftlarn. The geophysical survey revealed two cross-cutting glacial basins, with the MIS 8 basin being cut by a younger basin of undetermined age. Based on the luminescence dating results and the geophysical survey, a mid-Pleistocene landscape development model of the Isar-Loisach paleo-glacier region is presented.

Modern pollen deposition studies are essential to forestry and palaeoecological research, as they provide the key to understanding the relationship between the abundance of palynomorphs in natural (moss, litter, top core sediment) or artificial traps and the surrounding vegetation cover. In 1996, the EPMP (European Pollen Monitoring Programme) laid the foundations for pollen monitoring research in Europe, involving several countries and dozens of researchers in placing “Tauber-style” artificial traps across a wide range of ecosystems, and legitimising the collection of mosses for comparative studies. Here, we propose a straightforward, fast, and effective procedure—developed within the ALIVE “TrAcking Long-term declIne of forest biodiVErsity in Italy to support conservation actions” Project—for the collection of moss polsters and vegetation data, aimed at monitoring modern pollen deposition at the national scale. This protocol addresses a gap in existing literature, as no shared fieldwork guidelines are currently available. We demonstrate how the spatial pattern of modern pollen deposition can be investigated using two of the ALIVE Project’s target taxa (Fagus and evergreen Quercus) to explore the potential of microbotanical data in reflecting the current distribution of forest tree taxa at a national scale. The data collected within the ALIVE Project provide a synoptic picture of pollen deposition across Italy’s highly diversified landscapes and allow for preliminary considerations on the relationships between pollen deposition and modern vegetation cover of forest taxa.

The forest ecosystems of large Mediterranean islands are critical hubs of evolutionary diversity with unique floristic composition and distinctive vegetation patterns reflecting long-term population dynamics and ecological legacies. Mediterranean islands provide invaluable natural archives, preserving crucial insights into the resilience of past forest ecosystems and their responses to climate variability. In this paper, we provide a comprehensive overview of the Holocene vegetation history of major western Mediterranean islands, with the twofold aim of examining the timing, extent, and rates of vegetation changes over the last few thousand years, and evaluating the influence of Rapid Climate Changes (RCCs) on forest ecosystems. The rate of change analysis allowed the identification of a distinct pattern of rapid shifts in forest composition, corresponding to periods of climate instability. These shifts align with the periodicity of Bond events, suggesting synchronicity between changes in forest ecosystems and centennial-scale climatic oscillations at a supra-regional scale. A REDFIT spectral analysis applied to palynological proxies of forest cover changes identified prominent periodicities suggesting a direct influence of solar activity and/or a relation with complex ocean–atmosphere circulation mechanisms triggered by global climate forcings.

Paleoclimate and paleoenvironmental stratigraphic reconstructions from temperate glaciers are hindered by surface melting and ice metamorphism, which cause mobilization and concentration of impurities, as well as their interaction through englacial reactions.Despite meltwater intrusions, other impurities such as pollen grains and other palynomorphs remain to their original depth of deposition thanks to their large grain-size. Temperate glaciers close to vegetated areas, therefore, can include palynomorphs of different types that i) can be reliable annual markers for ice-core dating and, ii) allow reconstructing paleoenvironmental changes through time.The Adamello Glacier (Central Alps, Italy) is a temperate glacier that extends over ca 14.35 km2 (2020) at elevations ranging between 2560 and 3420 m a.s.l. In the framework of the CLIMADA Project, a 224 m long ice core (ADA 270) was recovered in 2021 from Pian di Neve, the summit plateau at about 3200 m a.s.l. in the accumulation area of the glacier. Preliminary estimates date the surface ice of the glacier to the 1980s while the bottom of the core might be Medieval in age. Radionuclide-based dating (3H, 14C, 137Cs, 210Pb) is in progress.The multiproxy approach adopted in this study includes black carbon, dust grain size and mineralogy, oxygen and hydrogen stable isotopes and palynomorphs, these last being the main object of this work. Given the site location, the palaeoecological signal is believed to be of regional significance.Despite the stratigraphy may not be preserved for some soluble chemical species, the core contains a high variety of palynomorphs, which allow the reconstruction of palaeoenvironmental and paleoclimatic variations at subannual resolution. The mean ice accumulation rate is about 0.9 m w.eq. yr-1. Consequently, the mean sampling resolution adopted for the palynomorph study is 0.1 m, increased to 0.01 m in specific intervals. Palynomorphs are mainly found in layers representing the spring-summer deposition while their concentration is very low during other periods of the year. Pollen grains, spores, diatom frustules, phytoliths and charcoals characterize the spring-summer layers; glass shards of volcanic origin and green algae have been observed in few intervals. Sporadic but massive Saharan dust events, carrying characteristic dust particles and pollen of African provenance, were identified throughout the core. The comparison between these intervals and the historical “red rain” events in Northern Italy will help better constraining the ice core dating.At ca 66 m depth, an ice interval characterized by a high impurity content has been investigated at 0.01 m resolution. Different palynomorphs are recorded in this interval, implying a quasi-continuous presence of humans and animals on the glacier for few years. Preliminary results link these layers to World War I, intensively fought between Italians and Austro-Hungarians on the slopes surrounding the Pian di Neve. The comparison between historical, archeological and ice core data allow delineating, at subannual resolution, the climate and environmental changes that characterized those years.

Human activity has fundamentally altered wildfire on Earth, creating serious consequences for human health, global biodiversity, and climate change. However, it remains difficult to predict fire interactions with land use, management, and climate change, representing a serious knowledge gap and vulnerability. We used expert assessment to combine opinions about past and future fire regimes from 98 wildfire researchers. We asked for quantitative and qualitative assessments of the frequency, type, and implications of fire regime change from the beginning of the Holocene through the year 2300. Respondents indicated that direct human activity was already influencing wildfires locally since at least ^~ 12,000 years BP, though natural climate variability remained the dominant driver of fire regime until around 5000 years BP. Responses showed a ten-fold increase in the rate of wildfire regime change during the last 250 years compared with the rest of the Holocene, corresponding first with the intensification and extensification of land use and later with anthropogenic climate change. Looking to the future, fire regimes were predicted to intensify, with increases in fire frequency, severity, and/or size in all biomes except grassland ecosystems. Fire regime showed quite different climate sensitivities across biomes, but the likelihood of fire regime change increased with higher greenhouse gas emission scenarios for all biomes. Biodiversity, carbon storage, and other ecosystem services were predicted to decrease for most biomes under higher emission scenarios. We present recommendations for adaptation and mitigation under emerging fire regimes, concluding that management options are seriously constrained under higher emission scenarios.

This study investigates the distribution of vegetation and its modern pollen representation along an elevation gradient in the Italian Alps and explores the relationships with terrain and climate variables. Moss polsters were collected at 25 sites between ca. 300 and 1400 m asl from open areas, deciduous, and conifer forests. At each site vegetation was surveyed at 1.8 and 10 m radius according to the Braun-Blanquet method. Climatic data, bioclimatic indices, and terrain parameters were obtained for each sampling site. Three distinct pollen associations reflect the characteristic vegetation altitudinal belts present in the study area. Uphill dispersal, the regional load and the presence of high producers influence the abundance of pollen and the representation of taxa along the gradient. CCA ordination technique reveals the predictive power of environmental variables on modern pollen and vegetation datasets. The most relevant factors controlling vegetation distribution are identified in elevation, insolation, Pspring, Tsummer, the Ellenberg quotient, and Summer Water Balance (SWB). Elevation, insolation, summer P and T, the Ellenberg quotient, and the Gams’ hygric continentality index (GAMS) explain more variance within the pollen dataset. A qualitative comparison among pollen and the corresponding parent plant occurrence qualifies Abies alba, Fagus sylvatica, Poaceae and Cyclamen pollen as suitable indicators taxa of the local vegetation in the study area. Several high producers with very effective, long-distance anemophilous dispersal ( Pinus, Ostrya, Alnus, and Juglans) or mixed pollination mechanisms (anemophilous and insect-pollination: Fraxinus ornus, and Castanea) show no or little association with their parent plants.