Science for social licence to arrest an ecosystem-transforming invasion.

The primary role for scientific information in addressing complex environmental problems, such as biological invasions, is generally assumed to be as a guide for management decisions. However, scientific information often plays a minor role in decision-making, with practitioners instead relying on professional experience and local knowledge. We explore alternative pathways by which scientific information could help reduce the spread and impacts of invasive species.

Integrating design and ecological theory to achieve adaptive diverse pastures.

Increasing plant diversity is often suggested as a way of overcoming some of the challenges faced by managers of intensive pasture systems, but it is unclear how to design the most suitable plant mixtures. Using innovative design theory, we identify two conceptual shifts that foster potentially beneficial design approaches. Firstly, reframing the goal of mixture design to supporting ecological integrity, rather than delivering lists of desired outcomes, leads to flexible design approaches that support context-specific solutions that should operate within identifiable ecological limits.

Resource-use efficiency drives overyielding via enhanced complementarity.

Overyielding, the primary metric for assessing biodiversity effects on ecosystem functions, is often partitioned into "complementarity" and "selection" components, but this reveals nothing about the role of increased resource use, resource-use efficiency, or trait plasticity. We obtained multiple overyielding values by comparing productivity in a five-species mixture to expected values from its component monocultures at a) six levels of nitrogen addition (spanning 0-500 kg N ha year) and b) across four seasons. We also measured light, water, and nitrogen use, resource-use efficiency, and three functional traits-leaf nitrogen content, specific leaf area, and leaf area ratio-n mixtures and monocultures.

Trait probability density (TPD): measuring functional diversity across scales based on TPD with R.

Functional diversity (FD) has the potential to address many ecological questions, from impacts of global change on biodiversity to ecological restoration. There are several methods estimating the different components of FD. However, most of these methods can only be computed at limited spatial scales and cannot account for intraspecific trait variability (ITV), despite its significant contribution to FD.

Are endemics functionally distinct? Leaf traits of native and exotic woody species in a New Zealand forest.

Recent studies have concluded that native and invasive species share a common set of trait relationships. However, native species in isolated regions might be functionally constrained by their unique evolutionary histories such that they follow different carbon capture strategies than introduced species. We compared leaf traits relating to resource investment, carbon return, and resource-use efficiency in 16 native (endemic) and three non-native (invasive) species in a temperate forest in Canterbury, South Island, New Zealand.

Combining field experiments and predictive models to assess potential for increased plant diversity to climate-proof intensive agriculture.

Agricultural production systems face increasing threats from more frequent and extreme weather fluctuations associated with global climate change. While there is mounting evidence that increased plant community diversity can reduce the variability of ecosystem functions (such as primary productivity) in the face of environmental fluctuation, there has been little work testing whether this is true for intensively managed agricultural systems. Using statistical modeling techniques to fit environment-productivity relationships offers an efficient means of leveraging hard-won experimental data to compare the potential variability of different mixtures across a wide range of environmental contexts.

Leaf economics spectrum-productivity relationships in intensively grazed pastures depend on dominant species identity.

Plant functional traits are thought to drive variation in primary productivity. However, there is a lack of work examining how dominant species identity affects trait-productivity relationships. The productivity of 12 pasture mixtures was determined in a 3-year field experiment.

Traits Without Borders: Integrating Functional Diversity Across Scales.

Owing to the conceptual complexity of functional diversity (FD), a multitude of different methods are available for measuring it, with most being operational at only a small range of spatial scales. This causes uncertainty in ecological interpretations and limits the potential to generalize findings across studies or compare patterns across scales. We solve this problem by providing a unified framework expanding on and integrating existing approaches.

Functional traits reveal processes driving natural afforestation at large spatial scales.

An understanding of the processes governing natural afforestation over large spatial scales is vital for enhancing forest carbon sequestration. Models of tree species occurrence probability in non-forest vegetation could potentially identify the primary variables determining natural afforestation. However, inferring processes governing afforestation using tree species occurrence is potentially problematic, since it is impossible to know whether observed occurrences are due to recruitment or persistence of existing trees following disturbance.

A functional approach reveals community responses to disturbances.

Understanding the processes shaping biological communities under multiple disturbances is a core challenge in ecology and conservation science. Traditionally, ecologists have explored linkages between the severity and type of disturbance and the taxonomic structure of communities. Recent advances in the application of species traits, to assess the functional structure of communities, have provided an alternative approach that responds rapidly and consistently across taxa and ecosystems to multiple disturbances.

Functional structure of biological communities predicts ecosystem multifunctionality.

The accelerating rate of change in biodiversity patterns, mediated by ever increasing human pressures and global warming, demands a better understanding of the relationship between the structure of biological communities and ecosystem functioning (BEF). Recent investigations suggest that the functional structure of communities, i.e.

Dissipation and sorption of six commonly used pesticides in two contrasting soils of New Zealand.

We investigated dissipation and sorption of atrazine, terbuthylazine, bromacil, diazinon, hexazinone and procymidone in two contrasting New Zealand soils (0-10 cm and 40-50 cm) under controlled laboratory conditions. The six pesticides showed marked differences in their degradation rates in both top- and subsoils, and the estimated DT(50) values for the compounds were: 19-120 (atrazine), 10-36 (terbuthylazine), 12-46 (bromacil), 7-25 (diazinon), 8-92 (hexazinone) and 13-60 days for procymidone. Diazinon had the lowest range for DT(50) values, while bromacil and hexazinone gave the highest DT(50) values under any given condition on any soil type.

New multidimensional functional diversity indices for a multifaceted framework in functional ecology.

Functional diversity is increasingly identified as an important driver of ecosystem functioning. Various indices have been proposed to measure the functional diversity of a community, but there is still no consensus on which are most suitable. Indeed, none of the existing indices meets all the criteria required for general use.

Does niche overlap control relative abundance in French lacustrine fish communities? A new method incorporating functional traits.

1. The mechanisms that structure biological communities hold the key to understanding ecosystem functioning and the maintenance of biodiversity. Patterns of species abundances have been proposed as a means of differentiation between niche-based and neutral processes, but abundance information alone cannot provide unequivocal discrimination.

Evidence that niche specialization explains species-energy relationships in lake fish communities.

1. Interspecific niche differences have long been identified as a major explanation for the occurrence of species-rich communities. However, much fieldwork studying variation in local species richness has focused upon physical habitat attributes or regional factors, such as the size of the regional species pool.

Functional characters combined with null models reveal inconsistency in mechanisms of species turnover in lacustrine fish communities.

Functional characters have the potential to act as indicators of species turnover between local communities. Null models provide a powerful statistical approach to test for patterns using functional character information. A combined null model/functional character approach provides the ability to distinguish between the effect of competition and environmental filtering on species turnover.

Is the abundance of species determined by their functional traits? A new method with a test using plant communities.

The relation between functional traits and abundance of species has the potential to provide evidence on the mechanisms that structure local ecological communities. The niche-limitation/limiting-similarity hypothesis, derived from MacArthur and Levins' original concept, predicts that species that are similar to others in terms of functional traits will suffer greater competition and hence be less abundant. On the other hand, the environment-filtering/habitat-optimum hypothesis predicts that groups of species with functional traits that are close to the optimum for that environment, and are therefore similar to other species, will be more abundant.