the pastoral communities of the Andes should be included in any management program. n
Management & Applied Science Presented during CS11: Agricultural Wetlands, 6/8/2021 1:15PM 3:05PM ET
A NOVEL APPROACH TO QUANTIFYING CHANGE IN WETLAND DISTRIBUTION AND DRAINAGE (1850S2004) FOR CONSERVATION PLANNING IN MIXED-USE LANDSCAPE Lawlor, Stephanie, University of South Florida Flannagan, Claire Rains, Kai Rains, Mark Landry, Shawn Quantifying long-term changes in wetland distribution and drainage is an important step in conservation and restoration planning in agricultural landscapes. However, efforts to accurately map conditions prior to the advent of aerial photography are hindered by a lack of data, so early wetland loss and hydrological alterations have often eluded effective consideration in such efforts. To overcome this barrier, we developed and validated a frequency-intersect method utilizing 1850s Public Land Survey System data and original late-1800s maps. A new sampling approach was devised to delineate wetlands from 1950s aerial photos to quantify progressive changes in wetland distribution and drainage patterns in St. Lucie County (146,402 ha), Florida (USA), between the 1850s, 1950s and 2004. Using a GIS-based protocol, we discovered that St. Lucie County lost 86% of its wetland area between the 1850s-2004, with 69% of those losses to agriculture and 12% to urbanization. St. Lucie County was also extensively ditched and drained over this period, with drainage density increasing by three orders of magnitude, from 0.08 km/km² in the 1850s to 7 km/km² in the 1950s, and finally to 25 km/km² in 2004. This expanded drainage density has increased hydrologic connectivity by channelized flows, with the relative amount of the total wetland area within 100 m of a channel increasing 30-fold, from 2% in the 1850s, to 36% in 1950s, then to 60% in 2004. The techniques developed for this study show promising potential for prioritizing wetlands for conservation and restoration planning in St. Lucie County and other areas, including the entirety of the 48 conterminous states in the USA where historical data are widely available. Spatially explicit data generated by our techniques can better inform wetland conservation and restoration programs,
which were previously limited to assessments within time periods supported by aerial imagery alone, resulting in incomplete information regarding drivers of contemporary landscape patterns. For managers, detailed and accurate understanding of historical landscapes helps to identify conservation targets, define restoration approaches, evaluate successes, and prevent restoration project missteps. n Presented during CS11: Agricultural Wetlands
ADAPTIVE WATER MANAGEMENT FOR WETLAND CONSERVATION IN AGRICULTURAL LANDSCAPE Zou, Yuanchun, Adaptive water management for wetland conservation in agricultural landscape, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences To understand the current situation of contradiction between wetland and agricultural water uses in the main grain-producing areas in Amur River Basin, we analyzed the natural and socio-economic driving factors, and to take a typical wetland-agriculture system as a case to assess the water use conflict and put forward adaptive management suggestions. Results showed that the total surface water storage in the Sanjiang Plain wetlands has decreased from 14.4 billion t in the 1980s to 4.7 billion t in 2010s, which means that it has lost approximate 2/3, due to the wetland loss and degradation. The case study the Qixing River National Nature Reserve (QRNNR) showed that without the rapid development of paddy fields in the surrounding farms, the natural water resource endowment of Qixing River can fully meet the needs of the natural wetland ecosystems. Agricultural development for successive years, especially the dramatically increased requirement for water in paddy fields, intensified the water use conflict between wetlands and farmlands. When QRNNR and its surrounding farms were considered as a whole system, the total precipitation, evapotranspiration, groundwater recharge, groundwater extraction, and agricultural drainage were 1.25, 1.48, 0.23, 0.43 and 0.09 billion m3/a, respectively. The main reason for the local continuous decline of groundwater depth was that groundwater extraction was approximate twice as great as the total infiltration recharge from wetlands and farmlands. The management principles and key recommendations, e.g. improving the wetland water resources protection system and integrating wetland protection goals into agricultural policies, adaptive wetland techniques (stagger water transfer, accurate water recharge, ice and snow melting water resourced) and agricultural techniques (water-saving irrigation, soil water capacity increased, rainfed agriculture), as well as joint management of wetland surface-ground Wetland Science & Practice July 2021 195
