• Energy Research

There are inherent social, environmental, and economic trade-offs in agricultural systems, which by definition have been altered from their natural state by humans for food and fibre production. Consumers are increasingly concerned about the environmental and social impacts of agriculture, and with the increasing influence of social media, agribusinesses and industries can be held accountable for their actions in the public domain. Thus, environmental sustainability reporting is increasingly being viewed as a cost of doing business in agriculture. There are a number of approaches used to measure agroecosystem health (AEH) around the world, but they are generally designed to make comparisons at coarse spatial scales (i.e. nations) or report on specific management actions implemented at the local scale (i.e. farm, catchment, or sub-region). Here we present a simple, yet scientifically robust assessment framework that can be used to benchmark and monitor the specific impacts of agricultural management practices on the environment. The general principles are drawn from environmental monitoring and experiences gained in environmental assessments that are not necessarily agriculturally focussed. However, many commonly used environmental indicators are not suitable for AEH assessment because they do not explicitly link environmental outcomes to management actions; or they fail to separate specific agricultural impacts from broader cumulative impacts resulting from other industries or land uses. We recommend using a combination of diagnostic, outcome-based indicators, in addition to practice- and product-based measures to communicate efforts to improve agroecosystem health outcomes. The framework presented here enables assessments at local scales, but can be aggregated or disaggregated to report at finer or coarser scales. This flexibility ensures that the assessment is relevant to the proponent and stakeholders, while also providing a way to make comparisons between producers, industries, or regions as part of an adaptive monitoring and assessment framework. This also opens the door for industry-based AEH monitoring program to provide, or make use of information from government-funded environmental monitoring programs, with benefits to both.

AbstractAim  Insect biodiversity is often positively associated with habitat heterogeneity. However, this relationship depends on spatial scale, with most studies focused on differences between habitats at large scales with a variety of forest tree species. We examined fine‐scale heterogeneity in ground‐dwelling beetle assemblages under co‐occurring trees in the same subgenus: Eucalyptus melliodora A. Cunn. ex Schauer and E. blakelyi Maiden (Myrtaceae).Location  Critically endangered grassy woodland near Canberra, south‐eastern Australia.Methods  We used pitfall traps and Tullgren funnels to sample ground‐dwelling beetles from the litter environment under 47 trees, and examined differences in diversity and composition at spatial scales ranging from 100 to 1000 m.Results  Beetle assemblages under the two tree species had distinctive differences in diversity and composition. We found that E. melliodora supported a higher richness and abundance of beetles, but had higher compositional similarity among samples. In contrast, E. blakelyi had a lower abundance and species richness of beetles, but more variability in species composition among samples.Main conclusions  Our study shows that heterogeneity in litter habitat under co‐occurring and closely related eucalypt species can influence beetle assemblages at spatial scales of just hundreds of metres. The differential contribution to fine‐scale alpha and beta diversity by each eucalypt can be exploited for conservation purposes by ensuring an appropriate mix of the two species in the temperate woodlands where they co‐occur. This would help not only to maximize biodiversity at landscape scales, but also to maintain heterogeneity in species richness, trophic function and biomass at fine spatial scales.

AbstractLand-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.

Herbivory is an important selective pressure in the life history of most plant species, as it usually results in reduced plant fitness. In some situations, however, plants are able to compensate for the resources lost to herbivory and do not suffer any reduction in growth or reproduction after attack. We examined the ability of Lebanese cucumber (Cucumis sativus) to compensate for both pre-flowering and during-flowering foliar herbivory through increased photosynthetic efficiency and capacity. Plants that were damaged before flowering were able to compensate, in terms of vegetative biomass and fruit production for up to 80% leaf area loss. Plants that were damaged during the flowering period were less able to compensate and fruit production declined with increasing herbivory. Damaged plants had higher photosynthetic efficiency and capacity, and dissipated less light energy as heat. Herbivore-damaged plants may be induced to use a greater proportion of the absorbed light energy for photosynthesis as a result of altered carbohydrate source-sink relationships.