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Biological invasions often transcend political boundaries, but the capacity of countries to prevent invasions varies. How this variation in biosecurity affects the invasion risks posed to the countries involved is unclear. We aimed to improve the understanding of how the biosecurity of a country influences that of its neighbours. We developed six scenarios that describe biological invasions in regions with contiguous countries. Using data from alien species databases, socio‐economic and biodiversity data and species distribution models, we determined where 86 of 100 of the world's worst invasive species are likely to invade and have a negative impact in the future. Information on the capacity of countries to prevent invasions was used to determine whether such invasions could be avoided. For the selected species, we predicted 2,523 discrete invasions, most of which would have significant negative impacts and are unlikely to be prevented. Of these invasions, approximately a third were predicted to spread from the country in which the species first establishes to neighbouring countries where they would cause significant negative impacts. Most of these invasions are unlikely to be prevented as the country of first establishment has a low capacity to prevent invasions or has little incentive to do so as there will be no impact in that country. Regional biosecurity is therefore essential to prevent future harmful biological invasions. In consequence, we propose that the need for increased regional co‐operation to combat biological invasions be incorporated in global biodiversity targets. [ABSTRACT FROM AUTHOR]

A major challenge for the management of biological invasions is to ensure that data and information from basic inventories and ecological research are used alongside data from the monitoring and evaluation of interventions to trigger and improve policy and management responses. To address this issue, South Africa has committed to report on the status of biological invasions and their management every 3 years.We propose a framework of indicators for reporting on biological invasions at a country level; assess the feasibility of the indicators using South Africa as a case study; and outline steps needed for indicator development.We argue that a national status report on biological invasions should explicitly consider indicators for pathways, species, and sites, and should report on interventions in terms of inputs, outputs, and outcomes.We propose 20 indicators based on data currently available, as well as existing international policy initiatives. For each indicator, we have developed a factsheet that includes different hierarchical metrics (considering data availability) and provide suggestions on assigning confidence levels. We also combine these indicators into four high‐level indicators to facilitate broader reporting and describe how forecasted indicators based on the concept of invasion debt could assist with scenario planning.We found that many of the data required for these indicators are already available in South Africa, but they have been poorly collated to date. However, data for the indicators of most direct value to policy and planning—those dealing with the impact of biological invasions and the outcome of interventions—are scarce.Policy implications. The framework of indicators developed here, for what we believe is the first ever national‐level report on the status of biological invasions and their management, will facilitate the inclusion of biological invasions in environmental reporting at national and international levels. By identifying knowledge gaps, a status report will also focus efforts on determining the size of a country's invasion debt and what can be done to reduce it. [ABSTRACT FROM AUTHOR]

Understanding the extent to which organisms are affected by climate change and are capable of adapting to warming is essential for managing biodiversity. Recent macrophysiological analyses suggest that range-related responses to warming may be more coherent (less variable) and predictable in marine than in terrestrial systems., To examine this generalization, we investigate basal upper thermal tolerances (measured as CTmax), the extent of their phenotypic plasticity and the impacts of different rates of temperature change on these tolerances, in five species of intertidal crustaceans from three distinct thermal regimes, incorporating South African ( RSA) shores and sub-Antarctic Marion Island ( MI)., For all species, lower rates of change resulted in lower CTmax, while acclimation resulted in varied responses depending on the rate of temperature change. At fast rates of temperature change, higher temperature acclimation resulted in elevated CTmax, while at slow rates of change, acclimation had no effect or resulted in a decline in CTmax., Maximum habitat temperatures recorded at the organisms' microsites were lower than the CTmax for the MI populations but were above CTmax at slow rates of change for RSA populations. Thus, populations from more equatorward locations have a lower tolerance of extremes than those from cooler regions. In addition to reduced warming tolerance, RSA populations had a lower acclimation capacity than their sub-Antarctic counterparts., We find substantial differences in long-term responses among groups in different areas as a consequence of spatial variation in the interactions among basal tolerance, phenotypic plasticity and thermal environments. These outcomes emphasize the significance of examining forecasts using a range of data and approaches so that their certainty can be established to inform key policy decisions in a spatially appropriate context. [ABSTRACT FROM AUTHOR]