What is the evidence that invasive species are a significant contributor to the decline or loss of threatened species? A systematic review map

Abstract

Background: Invasive species have been reported as one of the leading causes of species extinction. However, the evidence to support or contest their effects on the decline and/or extinction of threatened species has been largely unavailable and few efforts have been made to collate such information. In order to develop national and international policies addressing the loss of threatened species, and to prioritise research and mitigation efforts, the evidence needs to be systematically reviewed and mapped to determine the importance of such effects. Methods/design: The searching of online publication databases, grey literature and other resources, such as recovery plans of endangered species, aims to gather existing evidence on whether invasive species are a significant contributor to the decline and/or extinction of threatened species. This study focuses on US species under threat. The methods used to carry out the systematic review will address the following two fundamental questions: (a) what proportion of threatened species have an invasive species as a significant contributor to their decline and (b) through what mechanisms do invasive species contribute towards the decline of native species? The pool of resources gathered will be analysed for relevance and quality using a pre-defined scoring system. A systematic map will be produced, summarising information from individual studies. Where possible, data will be extracted from included studies and synthesised using meta-analysis.

What are ‘Integrated Landscape Approaches’ and how effectively have they been implemented in the tropics: a systematic map protocol

“…The map will follow a population-intervention-comparator-outcome (P.I.C.O) framework which provides the basic rationale for evidence-based systematic literature searches [21]. In order to be retained at each stage of the literature screening, studies will have to conform to the following inclusion (P.I.C.O) and exclusion criteria:…”

“…A basic checklist of quality criteria adapted from previous systematic maps [21,62], has been developed against which studies will be assessed. For inclusion for synthesis, studies must demonstrate:…”

“…Two researchers will work independently applying the inclusion/exclusion criteria through three sequential stages (see Figure one [21]) in order to sort for relevance, assess study quality and generate data collection. Prior to screening, the two researchers will perform a Kappa analysis at title and abstract level on a random subset of 100 articles identified in the scoping process to test consistency and objectivity between reviewers [60,61].…”

Effect of Social and Institutional Fragmentation on Collective Action in Peri-Urban Settings

“…Invasive animals also have a substantial ecological impact (Roberts et al 2013 ). In New South Wales they are implicated in 40 % of the threatened biodiversity, threatening 388 native species that constitute 83 % of endangered animal populations and 38 % of endangered ecological communities.…”

What is the evidence that invasive species are a significant contributor to the decline or loss of threatened species? A Systematic Map

“…In the original protocol [9], quantitative analysis was planned to be undertaken on any data that was suitable for formal statistical analysis. Where possible, meta-analyses for each of the interventions were to be undertaken, with the reasons for heterogeneity assessed by meta-regression (univariate or multivariate).…”