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A seguito degli scenari imposti dal cambio climatico il miglioramento dell’efficienza di uso dell’acqua (WUE) delle colture sono divenuti obiettivi fondamentali da perseguire. Il seguente studio pone al centro la WUE come parametro fisiologico cardine nella definizione del comportamento della vite in caso di riduzione della disponibilità idrica e si pone come obiettivo di valutarne le diverse forme di espressione, per individuare quale di queste sia meglio correlata alle performance delle varietà considerate, al fine di ottenere dati oggettivi che consentano di derivare consigli per la messa a punto di una più idonea tecnica irrigua. Nel triennio è stata valutata la risposta fisiologica di Sangiovese e Montepulciano, sottoposti a stress idrico di differente intensità in fasi fenologiche diverse. Inoltre, sono state saggiate le potenzialità genetiche della vite in condizioni di limitata disponibilità idrica attraverso il confronto delle performance di viti di Sangiovese innestate su due diversi portinnesti, ovvero confrontando un genotipo tradizionalmente sensibile, SO4, con uno selezionato in funzione della resistenza allo stress idrico, ovvero M4. Tutte le ricerche sono state condotte implementando apparati di misura innovativi che hanno permesso di ottenere la stima dell’efficienza di uso dell’acqua dell’intera chioma per la durata complessiva di ciascuna prova, poi confrontata con le forme più usuali di espressione di questo parametro fisiologico. Il lavoro rimette in discussione la metodologia e le deduzioni che si possono trarre da determinazioni di WUE condotte su singola foglia che, nella grande maggioranza dei casi, non hanno trovato corrispondenza nelle misure che hanno interessato l’intera chioma. / Within the current climate change scenario, the optimization of irrigation water use in vineyards by improving its water use efficiency (WUE) is a core subject of interest to assure sustainability in viticulture. The following research focuses on the physiological parameter WUE as pivotal in defining the behavior of grapevine under water stress. The aim is to assess the various forms of expression of the parameter, to identify which of these better correlates to the performance of the considered varieties, in order to obtain objective data and to derive recommendations for a more suitable irrigation technique. Over three years we evaluated physiological responses of Sangiovese and Montepulciano vines subjected to progressive water deficit either pre and post-veraison. Moreover, the genetic potential of grapevine under conditions of limited water availability was tested through the comparison of the performance of Sangiovese vines grafted on two different rootstocks; SO4, a traditional susceptible genotype and M4, a recently selected scion supposed to be tolerant to water stress. During the research we also designed, implemented and tested an innovative apparatus able to run automated water deficit experiments and to concurrently monitor whole canopy even for a season long time frame. These measurements were compared to traditional single leaf readings and a general conclusion was that, in most cases, single leaf WUE assessment did not match with the measures obtained from the whole canopy enclosure system.

While much attention has been given to the ways local communities may be impacted by climate change, this dissertation focuses ethnographically on the local agencies decision-making processes, a less-studied aspect of this topic. The primary purpose of this dissertation research is to understand how government agencies in southern Florida integrate climate change into their decision-making processes while dealing with political resistance. This research expands our understanding on the cultural politics of a new kind of environmental change, where national and international climate-change politics is brought into local water politics to illuminate how new and not so new visions about life in the contemporary metropolis collide and collude. Using multiple research methods including ethnographic fieldwork, participant observation, semi-structured interviews, and document research, I analyze the activities of the Miami-Dade County Climate Change Advisory Task Force Committee (MDC-CCATF) as well as the water management practices of the regional water management agency, the South Florida Water Management District (SFWMD). My findings include the following: (1) the Task Force activities have spearheaded Miami’s institutional adaptation to climate change; (2) historic legacies have expanded and complicated decision-making processes at the District; (3) a focus on the certainties of climate-change science allows climate change to persist in politically contentious planning contexts. My dissertation concluded that while planning for potential climate-change impacts can be difficult due to multiple institutional constraints that resource agencies like the District have, scientists and policy-makers have crafted an innovative culture that is particularly visible at sites where science and decision making intersect.