ABSTRACT
Socioeconomic demand for natural capital is causing catastrophic losses of biodiversity and ecosystem functionality, most notably in regions where socioeconomic-and eco-systems compete for natural capital, e.g., energy (animal or plant matter). However, a poor quantitative understanding of what natural capital is needed to support biodiversity in ecosystems, while at the same time satisfy human development needs-those associated with human development within socioeconomic systems-undermines our ability to sustainably manage global stocks of natural capital. Here we describe a novel concept and accompanying methodology (relating the adult body mass of terrestrial species to their requirements for land area, water, and energy) to quantify the natural capital needed to support terrestrial species within ecosystems, analogous to how natural capital use by humans is quantified in a socioeconomic context. We apply this methodology to quantify the amount of natural capital needed to support species observed using a specific surveyed site in Scotland. We find that the site can support a larger assemblage of species than those observed using the site; a primary aim of the rewilding project taking place there. This method conceptualises, for the first time, a comprehensive "dual-system" approach: modelling natural capital use in socioeconomic-and eco-systems simultaneously. It can facilitate the management of natural capital at the global scale, and in both the conservation and creation (e.g., rewilding) of biodiversity within managed ecosystems, representing an advancement in determining what socioeconomic trade-offs are needed to achieve contemporary conservation targets alongside ongoing human development.
ABSTRACT
The shallow overturning circulation of the oceans transports heat from the tropics to the mid-latitudes. This overturning also influences the uptake and storage of anthropogenic carbon (Cant). We demonstrate this by quantifying the relative importance of ocean thermodynamics, circulation and biogeochemistry in a global biochemistry and circulation model. Almost 2/3 of the Cant ocean uptake enters via gas exchange in waters that are lighter than the base of the ventilated thermocline. However, almost 2/3 of the excess Cant is stored below the thermocline. Our analysis shows that subtropical waters are a dominant component in the formation of subpolar waters and that these water masses essentially form a common Cant reservoir. This new method developed and presented here is intrinsically Lagrangian, as it by construction only considers the velocity or transport of waters across isopycnals. More generally, our approach provides an integral framework for linking ocean thermodynamics with biogeochemistry.
ABSTRACT
A protocol to enumerate particle-associated microbial indicator bacteria (heterotrophic plate count [HPC], enterococci [ENT] and Clostridium perfringens [CP]) by membrane filtration in a tropical stream is proposed that relies on high-speed homogenization and chemical treatment. Application of this protocol to stream samples suggest that ENT measurements are more biased by the presence of aggregates than HPC or CP. Whole sample treatment typically increased the colony forming units (CFU) count by 9-52%. Analysis of different settled fractions and examination of the number of indicators recoverable from particles retained on a 5 microm filter in relation to the number of particles containing target indicators both indicate that relatively more ENT form aggregates than HPC or CP. Although the bias is smallest for CP, this does not imply that CP is a better indicator as this depends on the unknown extent to which pathogens are themselves found associated with particles.
