Mestrado em Engenharia Agronómica. Universidade de Lisboa, Instituto Superior de Agronomia | A absorção de água pelas folhas (Foliar Water Uptake, FWU) é um fenómeno que ocorre em diferentes espécies de plantas de diversos ecossistemas e pode ser um complemento à água absorvida pelas raízes, com a capacidade de melhorar o estado hídrico das plantas. Quanto aos ecossistemas Mediterrânicos, pouco se sabe sobre a FWU. No entanto, com o aumento da aridez previsto em consequência das alterações climáticas, a FWU poderá assumir uma importância cada vez maior no funcionamento e resiliência destes ecossistemas e, em particular dos montados, onde se tem vindo a observar um aumento da mortalidade e perda de vitalidade do sobreiro (Quercus suber). Além disso, a FWU será especialmente relevante em eventos de pequena precipitação, formação de orvalho e nevoeiro. Neste estudo, pretendeu-se avaliar a ocorrência da FWU em sobreiro, qual a sua contribuição para o estado hídrico das árvores e se será maior em locais mais secos. Para tal, estabeleceu-se um ensaio em condições controladas com plantas de sobreiro de duas proveniências (Companhia das Lezírias e Vila Viçosa), as quais foram submetidas a diferentes disponibilidades hídricas: bem regadas (W), seca (D, regadas a cada duas semana) e pulverizadas (S, rega do D + pulverizadas 3 x semana). Mediu-se periodicamente o potencial hídrico de madrugada e ao meio-dia e determinou-se a FWU. O crescimento e a mortalidade foram avaliados no final do ensaio. A FWU ocorreu em 76% das folhas amostradas (n=450), que conduziram à entrada de água de 0,66 ± 0,02 mg cm-2 de folha (média ± erro padrão), com o consequente ganho de 5,4 ± 0,2% do teor relativo em água e uma melhoria do estado hídrico de 0,44 ± 0,02 MPa. Não foram observadas diferenças entre proveniências na FWU. A pulverização teve um efeito benéfico nas plantas, atrasando a progressão do stresse hídrico, que se refletiu em maior sobrevivência. | Water uptake by leaves (Foliar Water Uptake, FWU) is a phenomenon that occurs in different plant species from various ecosystems and can complement root water uptake, enhancing the hydric state of the plants. Regarding Mediterranean ecosystems, little is known about FWU. However, with the expected increase in aridity due to climate change, FWU may become increasingly important in the functioning and resilience of these ecosystems, particularly in cork oak forests, where an increase in cork oak (Quercus suber L.) mortality and loss of vitality has been observed. Additionally, FWU will be especially relevant during events of low precipitation, dew formation, and fog. This study aimed to assess the occurrence of FWU in cork oak, its contribution to the trees hydric state, and whether it is more pronounced in drier locations. To do so, an experiment was conducted under controlled conditions using cork oak plants from two different sources (Companhia das Lezírias and Vila Viçosa). These plants were subjected to various watering regimes: well-watered (W), dry (D, watered every two weeks), and sprayed (S, D + sprayed three times a week). Morning and midday leaf water potential were periodically measured, and FWU was determined. Growth and mortality were assessed at the end of the experiment. FWU occurred in 76% of the sampled leaves (n=450), resulting on a water uptake of 0,66 ± 0,02 mg cm-2 of leaf (mean ± standard error), leading to a gain of 5,4 ± 0,2% in relative water content and an improvement in the hydric state of 0,44 ± 0,02 MPa. No differences in FWU were observed between the two sources. Spraying had a beneficial effect on the plants, delaying the onset of water stress, which translated into higher survival rates. | N/A

The purpose of this study is to analyze and compare how irrigators and water supply face droughts situations in the 21st century, such as droughts in 2005-2008 and 2017-2018, in the Southeast of Spain. Methodologically, it is a study of Regional Geography with qualitative and quantitative analy­sis, diachronic and comparative, which includes an extensive field work. Among the sources used, it can be pointed out the historical archives, AEMET data, water consumption data regarding irrigation and urban supply, and interviews with managers and users. The response to droughts of the 21st cen­tury has been different. In the drought of 2005-2008, irrigators had to reduce the area in half in Yéchar (Mula). Regarding water supply, drought wells and transfers of rights were used. In the 2017-2018 drought, new technologies in irrigation and cultivation systems and desalination have been applied. In the case of supplies, the offer has been completed with the contributions of desalination. Water mana­gement faces the challenge of climate change scenarios in which extreme events such as droughts and floods will be more frequent and may generate difficulties (supply guarantee failure) to meet the water and food demands of a growing population. | El objeto de estudio es analizar y comparar cómo responden regantes y abastecimientos a situaciones de sequía en el Sureste de España en el siglo XXI, con el ejemplo de las de 2005-2008 y 2017-2018. Metodológicamente es un estudio de geografía regional con análisis cualitativo y cuantitativo, diacrónico y comparado, y trabajo de campo. Entre las fuentes utilizadas sobresalen la consulta de archivos históricos, los datos de AEMET, los consumos de agua en abastecimientos y regadíos, y las entrevistas a gestores y usuarios. La respuesta ante las sequías del siglo XXI ha sido dispar. En la de 2005-2008, en el regadío hubo que reducir la superficie de arbolado; en abastecimientos, se recurrió a pozos de sequía y cesiones de derechos. En la de 2017-2018, se han aplicado nuevas tecnologías en sistemas de riego y de cultivo, aparte de algunos aportes de desalinización; en el caso de los abastecimientos, se ha completado la oferta con agua producto de la desalación. La gestión del agua se enfrenta al reto de escenarios de cambio climático en el que serán más frecuentes sucesos extremos como sequías e inundaciones que generarán dificultades (fallo de garantía de suministro) para satisfacer las demandas hídrica y alimentaria de una población creciente.

The relationship between ecosystem and ecosystem services is revisited in order to integrate these concepts to water yield, as an important service provided by watersheds for human welfare. We propose that in watersheds disturbed by human activities, water yield can by re-established using the ecological restoration principles and practices. We also suggest a reference image integrating social, economic and environmental dimensions, and at the same time increasing research and education capacities. We discuss research progress in Chile regarding these issues referred to a study in small watersheds in the Reserva Costera Valdiviana, projected as a Long Term Ecosystem Research site. We conclude that it is necessary to improve both, scientific knowledge and outreach programs about ecosystem services, through a transdisciplinary approach and methods. | Se revisa la relación entre ecosistemas y servicios ecosistémicos, integrándolos a la provisión de agua en cuencas hidrográficas, uno de los servicios más importantes para el bienestar de las personas. Se propone que en cuencas alteradas por actividades antropogénicas, la provisión de agua puede ser recuperada utilizando los principios y prácticas de la restauración ecológica; y se propone una imagen de referencia que integre aspectos ambientales, económicos y sociales, e incluya el incremento de la investigación científica y educación. Se discuten algunos avances en Chile referidos a un estudio a escala de pequeñas cuencas en la Reserva Costera Valdiviana, que se proyecta como una estación de estudios ecosistémicos de largo plazo. Se concluye que es necesario avanzar urgentemente en el conocimiento científico y su divulgación social, respecto a los servicios ecosistémicos, incorporando enfoques de trabajo y metodologías transdisciplinarias.

La presente investigación buscó analizar los resultados obtenidos del proyecto “Adaptación a los impactos climáticos en regulación y suministro de agua en el área de Chingaza – Sumapaz – Guerrero” que fue desarrollado por Conservación Internacional en el municipio de Guasca, Cundinamarca, específicamente en la ronda hídrica del río Chipatá, dentro de la jurisdicción de las veredas Floresta II y Santa Ana alta, y que significó el uso de recursos humanos, económicos y tecnológicos considerables. Para realizar la evaluación de los resultados del proyecto se analizaron algunas variables de sostenibilidad resultantes de la investigación hecha por Viviana Abadía (2017) en su trabajo de grado de posgrado, titulado “Evaluación de la relación entre sostenibilidad y soberanía alimentaria - en el municipio de Turmequé Boyacá, Colombia". Partiendo de las diferentes variables identificadas dentro de las dimensiones económica, ambiental y social, y del diagnóstico inicial del proyecto, se hizo una evaluación con ayuda de entrevistas a los beneficiarios del proyecto, con lo que se pudo determinar el cumplimiento objetivo de cada variable en los agroecosistemas productivos de cada área, finalmente se generó una propuesta que recogió las experiencias positivas y negativas del proyecto de adaptación al cambio climático, con el fin de replicar este tipo de medidas sobre otros territorios con características similares. | The present investigation sought to analyze the results obtained from the project "Adaptation to climate impacts in regulation and water supply in the Chingaza - Sumapaz - Guerrero area" that was developed by Conservation International in the municipality of Guasca, Cundinamarca, specifically in the round of the Chipatá river, within the jurisdiction of the villages Floresta II and Santa Ana Alta, and which meant the use of considerable human, economic and technological resources. To carry out the evaluation of the results of the project, some sustainability variables resulting from the research carried out by Viviana Abadía (2017) in her postgraduate degree work, entitled "Evaluation of the relationship between sustainability and food sovereignty - in the municipality of Turmequé Boyacá, Colombia". Based on the different variables identified within the economic, environmental and social dimensions, and the initial diagnosis of the project, an evaluation was made with the help of interviews with the beneficiaries of the project, with which it was possible to determine the objective compliance of each variable in the productive agroecosystems of each area, finally a proposal was generated that collected the positive and negative experiences of the climate change adaptation project, in order to replicate this type of measures on other territories with similar characteristics.