The aim of the WASTE FEW ULL project is to develop and test internationally applicable methods of identifying inefficiencies in a city-region's food-energy-water nexus. We will undertake this through an international network of industry/civic society-led Urban Living Labs (ULL) in four urban regions - UK (Bristol), Netherlands (Rotterdam), South Africa (Western Cape) and Brazil (Campinas). Partners in Norway and the USA will provide economic valuations of potential impact, and impact-led public education, outreach and dissemination. Waste occurs across food, energy and water systems; at the interface of these systems, waste increases significantly the over-consumption of our limited resources (FAO, 2017): food (e.g. energy lost in food storage), energy (e.g. used to clean water) and water (e.g. nutrients lost in sewage). Resource scarcity is not only a matter of efficiency, but of access, distribution and equality (Exner et al, 2013). Each urban context has different pressures and opportunities (Ravetz, 2000). The focus of the WASTE FEW ULL project is therefore not so much on the specific downstream challenges, but on upstream processes by which cities can identify, test and scale viable and feasible solutions that reduce the most pressing inefficiencies in each context.

Tropical rainforests are one of the planets most important stores of carbon, as well as being essential to water cycling at large scales. Within tropical forests the largest trees, with diameters exceeding 70 cm, store between 25-45% of the carbon, yet represent <4% of the total number of trees. These large trees also transport disproportionately more water than smaller individuals do, making them a conservation priority for the future. Large tropical trees are likely to be very old, with many between 200-500 years and some estimated to be >1400 years old. Therefore, they have survived historical extreme climate events, including drought. Yet, recent evidence suggests water transport limitations are likely to make larger trees more vulnerable to the more extreme, more frequent drought events, which are predicted for the future. However, we still do not understand how large trees manage to overcome the huge resistances associated with transporting water such large vertical distances, against gravity, which substantially increase the hydraulic stress the tree experiences in a given climate. This information is essential to understanding how vulnerable these iconic tropical trees will be to the predicted future increases in drought frequency and intensity. Large trees can minimise the effects of increasing resistance to water transport with height through changing multiple leaf and stem hydraulic traits vertically through their stem and canopy. However, data on these vertical changes are rare and do not exist for tropical trees. Consequently, there is limited knowledge concerning whether trees can or cannot compensate for the negative effects being taller has on their water transport capacity and therefore their vulnerability to future drought events. In this project we will combine novel measurements of vertical changes in tree anatomical, structural and hydraulic properties on the world's tallest tropical trees, in two different tropical regions - Amazonia and Borneo - to achieve the following aims: Aim 1: Determine how vertical changes in tree hydraulic and anatomical traits regulate the capacity of tall trees to maintain water transport to their leaves under different environmental conditions. Aim 2: Determine if key structural and architectural properties of tropical trees control the vertical gradients of plant hydraulic and anatomical properties. Aim 3: Determine how accounting for vertical gradients in hydraulic properties in tall tropical trees alters predictions of tropical forest water and carbon cycling. To achieve these aims we will study the tallest tropical trees in the world. This will include trees in Amazonia discovered in 2019 that reach 88.5 m tall, ~30m taller than any other tree recorded in the neotropics. We will compare these to equivalent sized trees in Borneo from the dipterocarp family, the family containing the tallest angiosperm species in the world. On these trees we will measure vertical gradients in hydraulic and anatomical traits on 60 trees varying in height from 20-90 m. These trees will come from eight dominant species in Brazil and Borneo, allowing us to contrast the hydraulic adaptations of trees species from drier, more seasonal climates (Brazil), to those of species that have evolved in wetter, a-seasonal climates (Borneo). To realise the three aims above, our novel vertical hydraulic trait measurements will be combined with measures of whole-tree water transport and storage, tree architectural data derived from state-of-the-art ground-based laser scanning and vegetation models. Combining these techniques will allow us to make a step-change in our current understanding of the limits to water transport in the world's tallest tropical trees and the impact this may have on carbon and water cycling under future climate scenarios.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Montane forests in the Andes and the South-eastern Brazilian Mountain Range host the highest plant biodiversity on Earth. Current rates of warming in the Andes are three times higher than elsewhere in S. America, and higher than average warming of 5-6oC is predicted by the end of this century. Hence, the (sub)tropical mountain ranges in Latin America form a high-priority area in which to study the response of tropical trees under future environmental change. Tropical forests also play a crucial role in the global carbon budget, accounting for more than half of terrestrial net primary production and storing around 40% of plant biomass. Uncertainty in the response of tropical forests to global warming is responsible for a large uncertainty in atmospheric CO2 concentrations under any given scenario of anthropogenic CO2 emissions. However, the current generation of Dynamic Global Vegetation and Earth System Models do not include a representation of montane forest functioning, which stems from a lack of empirical understanding, leading to a consideration of only lowland tropical forests in models. We intend to address this knowledge gap by initiating a Latin America-wide network of tropical montane forest sites to gather existing understanding in order to model the contribution of these forests to the regional and global carbon and water cycles, under current and future climate change. This will be achieved via a dedicated workshop at the Uni-Campinas, Brazil, hosted by PP-FAPESP Nagy, with the participation of empirical experts across the network together with DGVM and ESM modellers.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.