Island and Mountain Ecosystems as Testbeds for Biological Control in the Anthropocene

Abstract

For centuries, islands and mountains have incited the interest of naturalists, evolutionary biologists and ecologists. Islands have been the cradle for biogeography and speciation theories, while mountain ranges have informed how population adaptation to thermal floors shapes the distribution of species globally. Islands of varying size and mountains’ altitudinal ranges constitute unique “natural laboratories” where one can investigate the effects of species loss or global warming on ecosystem service delivery. Although invertebrate pollination or seed dispersal processes are steadily being examined, biological control research is lagging. While observations of a wider niche breadth among insect pollinators in small (i.e., species-poor) islands or at high (i.e., colder) altitudes likely also hold for biological control agents, such remains to be examined. In this Perspective piece, we draw on published datasets to show that island size alone does not explain biological control outcomes. Instead, one needs to account for species’ functional traits, habitat heterogeneity, host community make-up, phenology, site history or even anthropogenic forces. Meanwhile, data from mountain ranges show how parasitism rates of Noctuid moths and Tephritid fruit flies exhibit species- and context-dependent shifts with altitude. Nevertheless, future empirical work in mountain settings could clarify the thermal niche space of individual natural enemy taxa and overall thermal resilience of biological control. We further discuss how global databases can be screened, while ecological theories can be tested, and simulation models defined based upon observational or manipulative assays in either system. Doing so can yield unprecedented insights into the fate of biological control in the Anthropocene and inform ways to reinforce this vital ecosystem service under global environmental change scenarios.

Generalist Predators Shape Biotic Resistance along a Tropical Island Chain

“…In this study, we build upon earlier work to illuminate islands’ potential to inform biological control practice [ 45 ]. Drawing upon a set of observational and manipulative assays conducted across nine Indonesian islands, we investigate whether species richness (as tentatively defined by island size) affects predator recruitment in pest-invaded crops (for CAM, over 2017–2018) and mortality of the various developmental stages of an invasive herbivore (for FAW, during 2022).…”

SLAM Project - Long Term Ecological Study of the Impacts of Climate Change in the natural forests of Azores: V - New records of terrestrial arthropods after ten years of SLAM sampling

“…Islands are critical places for the conservation of biodiversity, there being a critical need to gather knowledge to support conservation management in such extremely dynamic and changing ecosystems ( Whittaker and Fernández-Palacios 2007 , Fernández-Palacios et al 2021 , Wyckhuys et al 2022 ). They harbour a unique diversity with often high levels of endemicity amongst many taxa ( MacArthur and Wilson 2001 , Borges et al 2019 , Fernández-Palacios et al 2021 , Florencio et al 2021 ).…”