Forest bolsters bird abundance, pest control and coffee yield

Abstract

We address criticism that the Transport, Establishment, Abundance, Spread, Impact (TEASI) framework does not facilitate objective mapping of risk assessment methods nor defines best practice. We explain why TEASI is appropriate for mapping, despite inherent challenges, and how TEASI offers considerations for best practices, rather than suggesting one best practice. Our review of alien species risk assessments (RA) (Leung et al. 2012) aimed to synthesise the diverse approaches applied in this field to establish a logical framework for best practices. We believe the TEASI framework that makes explicit the consideration of Transport, Establishment, Abundance, Spread and Impact aspects of biological invasions helps integrate the main ideas underlying risk assessment and identifies important open questions. Barry (2013) provided a thoughtful review of our study and while he found much to commend in our approach, he indicated two main criticisms: (1) the mapping process in the article was subjective and TEASI does not encapsulate all the reviewed RAs and (2) we are not explicit in defining the best practice. We address each criticism. First, although quantitative approaches were relatively easy to map onto the TEASI framework, scoring-based approaches were more difficult and more subjective. Importantly, subjective does not mean arbitrary. For instance, mapping RA questions such as 'propa-gules dispersed by wind' onto the Spread component in TEASI and identifying it as a species trait is arguably logical. However, the rationale for how answers were combined was less clear for scoring approaches. For instance, many simply summed binary yes/no answers across all components, so we agree that they 'would need to be radically redefined' to map onto TEASI as many do not consider model structure. Barry (2013) further notes that the scoring approaches 'are abstract while the TEASI model is process-based and explicit'. This is certainly true but if the 'abstract' risks do not (at least imperfectly) map onto the set of real processes underlying invasions, we question whether they can be predictive. Thus, we argue that scoring-based approaches can and should be considered in the context of a process-based framework, but we acknowledge that this is challenging. We view this difficulty in mapping model structure as a limitation of existing scoring methodology rather than of the process-based TEASI model. We pose the questions: do the scoring model structures make sense in terms of invasion processes? How? If they do not, in the future, should they? Note, we do not deny the value of scoring RAs; they will remain important in addressing biological invasions, given limited time, data and resources. In addition, Barry (2013) argues that TEASI equations were too highly structured and prescriptive. Although we could have just listed factors thought to be relevant for invasion risk, this would be less valuable. Models are useful, in part, exactly because they are highly structured, presenting a clear picture of how we believe factors rel...

Functional traits in agriculture: agrobiodiversity and ecosystem services

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Bats in the Anthropogenic Matrix: Challenges and Opportunities for the Conservation of Chiroptera and Their Ecosystem Services in Agricultural Landscapes

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