Assessing and interpreting changes in biodiversity


We can interpret the state of biodiversity by:

  • assessing whether objectives for biodiversity management set in policies and plans have been achieved
  • assessing whether the state of biodiversity is adequate to ensure that the processes that occur in ecosystems meet the needs of those ecosystems and of humans who depend on ecosystems for life fulfilment and life support
  • comparing the current state of biodiversity with some reference points in the past to establish trends.

The term ‘ecosystem services’ has been coined to describe benefits from the environment to humans, and to acknowledge that these benefits usually require interacting suites of species (i.e. ecosystems) rather than individual species. These benefits include services fundamental to human life, such as regulation of the atmosphere, maintenance of soil fertility, food production, regulation of water flows, filtration of water, pest control and waste disposal; and those that are social and cultural, such as experiencing nature. Figure 8.2 illustrates one framework for considering how ecosystem services link with human population growth and economic and other activities that consume natural resources.

Interpreting the relationship between the current state of biodiversity and the ecosystem services the environment provides is complicated, for two reasons:

  • Our understanding of the relationships between biodiversity and ecosystem functions is not yet good enough to predict in detail the effects of changes in biodiversity on benefits to humans
  • Our understanding of the needs that humans have for benefits from biodiversity is still too poor for us to be able to assess whether current or future states of biodiversity will be adequate to meet those needs.

Evidence suggests that, while at any point in time human needs might be met by only some of the species currently in existence, some species that currently play a minor role might become more important as the environment changes.8-9 Many species can thus be seen as backups or ‘insurance’ against future changes in the environment or human needs. Related evidence suggests that the amount and types of benefits to humans change as components of biodiversity change (Table 8.2).10 This uncertainty and lack of knowledge about the relationship between biodiversity and human wellbeing suggests an imperative to retain options and to make decisions that do not foreclose on future opportunities. This translates into the widely adopted policy goal of protecting existing species, ecosystems and ecosystem processes, and the conditions for them to persist and evolve. This policy goal is recognised internationally in the Convention on Biological Diversitya and nationally in Australia’s Biodiversity Conservation Strategy 2010–2030.11


Cork S (2011). Biodiversity: Assessing and interpreting changes in biodiversity. In: Australia state of the environment 2011, Australian Government Department of the Environment and Energy, Canberra,, DOI 10.4226/94/58b65ac828812