• Energy Research

STUDIO CONOSCITIVO DEI CAMBIAMENTI CLIMATICI E DI ALCUNI LORO IMPATTI IN FRIULI VENEZIA GIULIA PRIMO REPORT – marzo 2018 Supporto alla predisposizione di una strategia regionale di adattamento ai cambiamenti climatici e per le azioni di mitigazione

Land use and land cover (LULC) surrounding the Ngerengere River, Tanzania, which is a crucial water source, has led to a rapid decline in vegetated areas. Understanding these changes is vital for informed decision-making and sustainable river catchment management. This study assessed historical LULC trends from 2004 to 2024, projected the current trend of change to 2034, and analyzed the human activities driving the trends using Landsat TM imagery. The study utilized both spatial and non-spatial datasets from primary sources (Landsat imagery via Google Earth Engine and field surveys) and secondary sources (literature and government reports). Landsat 5 (2004) and Landsat 8 (2014, 2024) images were processed using Arc-GIS and QGIS to minimize cloud interference. Land cover classification combined unsupervised and supervised methods, validated with ground reference points collected through GPS. A rule-based classification system used spectral indices to identify land cover types. Classified maps were visualized and exported for further analysis. Furthermore, systematic field visits were conducted along the catchment to assess human land use activities, that is, agriculture, settlements, and deforestation. Results revealed a 17.6% decline in sparse vegetation between 2004 and 2014, and a further 27.01% decrease from 2014 to 2024. Bare land increased by 8.58% over the two decades. Built-up areas rose from 0.67% in 2004 to 5.44% in 2014, then dropped to 2.1% in 2024. In contrast, dense vegetation increased from 0.04% in 2004 to 7.13% in 2024. Overall, the land cover projection for 2034 indicates continued ecological transformation within the Ngerengere River catchment. These shifts, primarily driven by agricultural expansion and deforestation, underscore the urgent need for sustainable land management. The significant vegetation cover decline in the catchment is largely due to agricultural encroachment into forested areas.

ABSTRACT Increasing frequency and severity of drought events is posing risks to trees' health, including those planted in urban settlements. Drought‐induced decline of urban trees negatively affects ecosystem services of urban green spaces and implies cost for maintenance and removal of plants. We aimed at identifying physiological traits that can explain and predict the species‐specific vulnerability to climate change in urban habitats. We assessed the relationships between long‐term risk of decline of different tree species in a medium‐sized town and their key indicators of drought stress tolerance, i.e. turgor loss point (TLP) and vulnerability to xylem embolism (P50). Starting from 2012, the study area experienced several summer seasons with positive anomalies of temperature and negative anomalies of precipitation. This trend was coupled with increasing percentages of urban trees showing signs of crown die‐back and mortality. The species‐specific risk of decline was higher for species with less negative TLP and P50 values. The relationship between species‐specific risk of climate change‐induced decline of urban trees and key physiological indicators of drought tolerance confirms findings obtained in natural forests and highlights that TLP and P50 are useful indicators for species selection for tree plantation in towns, to mitigate negative impacts of climate change.

Abstract The worldwide decline of marine forests, due to human impacts and climate change, emphasizes the need to develop and implement effective and sustainable solutions to restore these endangered habitats and to re‐establish the services they provide. In this study, the ex situ restoration of Gongolaria barbata (=Treptacantha barbata), a Mediterranean subtidal habitat‐forming species of brown seaweed, was for the first time implemented in a marine protected area in the Adriatic Sea. Two restoration efforts were performed in 2019. The first was started in winter, after a marine heatwave that triggered early fertility, and the second in spring, when the species usually reproduces. This study aimed to evaluate: (i) the disruptive effects of a thermal anomaly on the reproductive biology and performance in culture of G. barbata; and (ii) the impact of the grazing pressure on juveniles after the outplanting. The first cultivation was more productive than the second, in terms of zygote release and germling growth. To mitigate the low efficiency of the second culture and to avoid prolonged highly demanding maintenance in the mesocosms, the cultivation period was extended outdoors using a structure suspended in the water column. The modular frames conceived for outplanting G. barbata proved to be effective because of their easy operability and low cost. Controlling for herbivorous fish had significant positive effects on both juvenile survival and growth. The outcomes highlighted that an unpredictable climatic event and fish grazing were major threats that impaired the restoration process of G. barbata. These stressors should be considered when developing plans to implement effective large‐scale restoration of canopy‐forming macroalgae.

The impacts of climate extremes on species, communities and ecosystems have become critical concerns to science and society. Under a changing climate, how restoration outcomes are affected by extreme climate variables is a largely unknown topic. We analyzed the effects of experimental factors (grazing and sowing of native species), extreme climate events (intense precipitation and extreme temperatures indexes) and their combination on the restoration progress of a dry, calcareous grassland in Tuscany (Italy) with a 1 year before/15 years continuous annual monitoring after, control/impact (BACI) experiment. Grazing had a beneficial effect on the diversity of the grassland, while sowing had a limited impact. The climatic index that most affected the entire plant community composition was the number of very heavy precipitation days. The interaction of grazing and extreme climatic indexes had a significant detrimental effect on restoration outcomes, increasing the cover of synanthropic and Cosmopolitan-Subcosmopolitan generalist species and decreasing the cover of more valuable species such endemic species. In the richest grazed plots, species richness showed a lower sensitivity to the average precipitation per wet day but in grazed site, restoration outcomes can be negatively influenced by the intensification of precipitation and temperature extremes. In a context of progressive tropicalization of the Mediterranean area, to assist managers setting achievable restoration goals, restoration practitioners should consider that climate extremes might interfere with the beneficial effects of restoration practices.

Italy is among the European countries with the greatest plant diversity due to both a great environmental heterogeneity and a long history of man-environment interactions. Trait-based approaches to ecological studies have developed greatly over recent decades worldwide, although several issues concerning the relationships between plant functional traits and the environment still lack sufficient empirical evaluation. In order to draw insights on the association between plant functional traits and direct and indirect human and natural pressures on the environmental drivers, here we summarize the existing knowledge on this topic by reviewing the results of studies performed in Italy adopting a functional trait approach on vascular plants, briophytes and lichens. Although we recorded trait measurements for 1418 taxa, our review highlighted some major gaps in plant traits knowledge: Mediterranean ecosystems are poorly represented; traits related to belowground organs are still overlooked; traits measurements for bryophytes and lichens are lacking. Finally, intraspecific variation has been little studied at community level so far. We conclude highlighting the need of approaches evaluating trait-environment relationship at large spatial and temporal scales and the need of a more effective contribution to online databases to tie more firmly Italian researchers to international scientific networks on plant traits.