Using Remote Sensing to Evaluate the Influence of Grassland Restoration Activities on Ecosystem Forage Provisioning Services

As valuation of ecosystem goods and services derived from ecological processes becomes increasingly important in environmental decision-making, the need to quantify how restoration activities influence ecosystem function has grown more urgent, particularly within income-generating or subsistence-providing landscapes where economic needs and biodiversity goals must be balanced. However, quantification of restoration effects is often hindered by logistical issues, which include (1) the difficulty of systematically monitoring responses over large areas and (2) lack or loss of comparison sites necessary for assessing treatment effect. We explored the use of remote sensing to quantify the effects of native grass seeding and prescribed burns on ecosystem forage provisioning services within a California (U.S.A.) rangeland landscape. We used Landsat time series to monitor forage (green biomass) dynamics within 296 ha of treatment areas—distributed throughout a 36-km² watershed—for 6 years and to identify post hoc comparison areas when a priori comparisons were lacking. Remote sensing analysis documented gains and losses in forage provisioning services due to restoration efforts and provided critical information for adaptive management. Our results demonstrate the degree to which invaded grasslands can be resistant to change and suggest that increasing the functional complexity of restoration mixes might help increase forage availability and reduce opportunities for weed reinvasion.