Island biodiversity conservation needs palaeoecology

Abstract

The discovery and colonization of islands by humans has invariably resulted in their widespread ecological transformation. The small and isolated populations of many island taxa, and their evolution in the absence of humans and their introduced taxa, mean that they are particularly vulnerable to human activities. Consequently, even the most degraded islands are a focus for restoration, eradication, and monitoring programmes to protect the remaining endemic and/or relict populations. Here, we build a framework that incorporates an assessment of the degree of change from multiple baseline reference periods using long-term ecological data. The use of multiple reference points may provide information on both the variability of natural systems and responses to successive waves of cultural transformation of island ecosystems, involving, for example, the alteration of fire and grazing regimes and the introduction of non-native species. We provide exemplification of how such approaches can provide valuable information for biodiversity conservation managers of island ecosystems.

Long-Term Habitat Degradation Drives Neotropical Macrophyte Species Loss While Assisting the Spread of Invasive Plant Species

“…A solution comes from the application of paleoecological techniques since most macrophyte species leave a sub-fossil remains in the sediments that can be tracked over time (Davidson et al, 2005;Salgado et al, 2010). This is a very useful technique that allows for the detection of invasive species, of pre-colonization or pre-spreading conditions (Nogué et al, 2017) and an understanding of changes in species distributions and abundances on a long-term basis (Salgado et al, 2018a).…”

Global Island Monitoring Scheme (GIMS): a proposal for the long-term coordinated survey and monitoring of native island forest biota

“…Nogué et al 2017), for comparative analyses. However, some caution should be taken when using only the most recent and oldest aerial photos, since these may lead to misleading conclusions if land cover change did not follow a linear pattern over time.…”

“…spatial and temporal turnover) from those that arise from, or are mediated by, anthropogenic activities (e.g. native forest loss) (Magurran et al 2010), specifically on islands (Nogué et al 2017). Long-term studies are needed to address this problem (e.g.…”

Combining Contemporary and Paleoecological Perspectives for Estimating Forest Resilience

“…Moreover, ecological history has been highlighted as crucial to determine the level of intervention required to restore an ecosystem that has been modified by human impacts to a more "naturally functioning state" (Jackson and Hobbs, 2009). Assessing ecological history was undertaken to inform management of island ecosystems, which included consideration of multiple baselines (Nogué et al, 2017). There are also some examples in the policy literature that have highlighted the importance of identifying baselines.…”

“…In practice, the assumption that the same areabased definition of intactness would necessarily correlate with resilience across all forests should be examined. Outlining clear baselines for initial anthropogenic disturbance have proved to be challenging (e.g., Nogué et al, 2017). Paleoecological records have already provided evidence of a long presence of human impacts on forest around the world.…”