D 3.14. Review on processes and effects of nutrients and organic material in lakes and threats due to climate change on current adaptive management and restoration efforts

The vast majority of the material that comprises the lake organic matter pool is in dissolved, rather than particulate, form (Birge and Juday 1934, Cole et al. 2007) and this dissolved pool is a complex mixture of humic and non-humic substances (Table 1). For the purposes of the present review, we will focus upon the effects of terrestrially-derived dissolved and particulate organic carbon (DOC and POC) upon lake ecosystems. While we recognise that organic matter also contains other ecologically important chemicals and nutrients, it is fluxes of terrestrial carbon to lake systems that have received much research attention. In the review, we provide an overview of current understanding of the effects of DOC and POC upon different elements of the lake food web, and ecosystem scale processes. We then consider the likely combined effects of increasing DOC loading, eutrophication and climate change upon lake ecosystems.