The recovery of riparian vegetation along rivers of coastal NSW since the 1980s: implications for working with river recovery in management

Clearance of vegetation, and de-snagging activities throughout the 19th and 20th centuries caused widespread river channel degradation across eastern Australia. However, following changes in land use and land management practices, coupled with decades of effort in river management, there has been a noticeable shift in the riparian vegetation condition of these rivers, particularly in coastal valleys of NSW. While geomorphic and vegetative recovery has been observed, we do not yet fully understand the timing and extent of recovery that has occurred. This understanding is critical to work with rivers as part of nature-based and process-based management practice. In order to understand vegetation changes in the last 33 years, we calculated NDVI difference from Landsat imageries for the time periods 1987-2003 (17 years), 2003-2020 (16 years) and for the full time period 1987-2020 (33 years). The NDVI difference was then analysed for 19 coastal catchments in NSW. The results show that 45% of stream length experienced riparian vegetation increase in the last three decades and this increase ranged from 32 to 61%. Overall, the latter period from 2003-2020 experienced greater vegetation increases than the earlier period 1987-2003.