Proportions endemic, exotic, threatened species

The loss of species of conservation interest or endemics should be assigned higher value than the loss of common species (Buckland et al. 2005). Metrics such as species richness, evenness and diversity can be insensitive to the loss of rare species; for example, at smaller scales conversion from one habitat to another could cause loss of endemic species, but overall richness and evenness could still increase (Buckland et al. 2005).

The rarity of species of conservation concern can provide additional challenges in effective monitoring, and monitoring objectives should be tailored to suit the attributes of the target species (Robinson et al. 2018, Lindenmayer et al. 2020). Accurate detection of population changes will require more intensive monitoring than conventional species surveys (Robinson et al. 2018, Martin et al. 2007). Nature-based Solutions projects are unlikely to support the entire population of a species, and monitoring will usually only capture presence, or with more intensive monitoring, population trends for a species within the project area.

Monitoring of exotic species can be important where they are invasive and have a disproportionate negative effect on ecosystem functioning or native species populations (Bradshaw et al. 2016, Ehrenfield 2010). Additionally, invasive species can increase species richness and functional/phylogenetic diversity, while having negative effects on native species (Santini et al. 2017).