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Marine macroalgae are important indicators of healthy nearshore groundwater dependent ecosystems (GDEs), which are emergent global conservation priorities. Submarine groundwater discharge (SGD) supports abundant native algal communities in GDEs via elevated but naturally derived nutrients. GDEs are threatened by anthropogenic nutrient inputs that pollute SGD above ambient levels, favoring invasive algae. Accordingly, this case study draws on the GDE conditions of Kona, Hawai'i where we evaluated daily photosynthetic production and growth for two macroalgae; a culturally valued native (Ulva lactuca) and an invasive (Hypnea musciformis). Manipulative experiments—devised to address future land-use, climate change, and water-use scenarios for Kona—tested algal responses under a natural range of SGD nutrient and salinity levels. Our analyses demonstrate that photosynthesis and growth in U. lactuca are optimal in low-salinity, high-nutrient waters, whereas productivity for H. musciformis appears limited to higher salinities despite elevated nutrient subsidies. These findings suggest that reductions in SGD via climate change decreases in rainfall or increased water-use from the aquifer may relax physiological constraints on H. musciformis. Collectively, this study reveals divergent physiologies of a native and an invasive macroalga to SGD and highlights the importance of maintaining SGD quantity and quality to protect nearshore GDEs. [ABSTRACT FROM AUTHOR]

Timber heritage faces numerous risks, with the threat from insect and fungal attack particularly sensitive to climate. The Scheffer index estimates the deterioration of wood by combining average temperature and days of rain. We determined the Scheffer index from twenty sites in Europe across the 20th and early 21st century using meteorological observations, largely from the European Climate Assessment Dataset. Results showed that Scheffer indices across Europe loosely align with Köppen climate classes, which are also defined in terms of temperature and rainfall. However, within a given Köppen class, a wide range of Scheffer indices were found, thus representing very different threats to heritage. This suggests that specific heritage climate parameters, such as the Scheffer index, are needed. Trends in the Scheffer index provide a fairly robust guide to management strategy by identifying locations where the risk for timber is increasing. However, a simple index cannot necessarily describe the complex interactions between biological pests and climate; such complexity is better handled with well-constructed models. Nevertheless, the Scheffer index offers heritage managers an easily calculated estimate of the spatial distribution of risk to timber and the likely direction of future change. [ABSTRACT FROM AUTHOR]

Pilgrimages are an important part of our intangible heritage. These long journeys, often on foot, can be sensitive to weather, so this study sees pilgrimages as providing an opportunity to look at the way in which changes in climate affect intangible heritage. It examines two important Ethiopian pilgrimages that involve hundreds of thousands who travel each year to Dirre Sheikh Hussein, seen as the country's Mecca, and Lalibela, its Jerusalem. These journeys in the cold season (December–February) often exceed 1000 km in length and expose pilgrims to low temperatures in mountain areas. Our analysis uses daily output data from ERA-5 and CHIRPS for rainfall and temperature across the recent past (1984–2014) and an ensemble of climate models (CMIP6) for the periods 1984–2014 and 2035–2065, to explore changes in nighttime low temperature, daytime high temperature and the potential increase in days of heavy rain in mountain areas. Additionally, we examine the increasing number of very hot days affecting travel to and from Dirre Sheikh Hussein. The pilgrims experience weather events and not long-term average conditions, so extremes and spells of inclement weather can affect their experience. Management plans for the regions have yet to address likely changes to climate at these religious sites, or consider how strategic planning might mitigate their impact on pilgrims. [ABSTRACT FROM AUTHOR]