USGS contribution to assessing mangrove conditions using a multidisciplinary approach Elitsa Peneva-Reed 24 October, 2017

USGS Wetlands Mapping USGS wide array of wetlands topics Coastal processes Coastal ecosystems Conservation Local, Regional, National, and International in scope USGS wetlands projects LCMAP (annual time-series) Dynamic surface water extent ECV Coastal National Elevation Database Applications Project (CoNED) – Wetland Lidar Research Mangrove mapping

The Big Picture Mangroves forests are an important ecosystem providing benefits for disaster protection, biodiversity and climate change mitigation However, in many cases there is not a good knowledge of area and structure change of mangroves areas. The developed methodology could be applied to other mangrove areas to study temporal and spatial dynamics of area, structure, carbon stock and carbon sequestration.

Mangrove Monitoring and Carbon Assessment Project USGS Biological Carbon Sequestration Assessment Program OVERVIEW The project integrates remote sensing and field data observations to monitor and estimate the above ground biomass and carbon stored in mangrove ecosystems and to create a baseline for future carbon sequestration estimates and forecasting in J.N. “Ding” Darling National Wildlife Refuge, Florida, USA and Pohnpei, Federated States of Micronesia. METHODOLOGY Annual Landsat Mapping and Assessment Field work to assess in situ biophysical characteristics Allometry to assess carbon stocks PRELIMINARY RESULTS Based on the Time Series Analysis Based on the Field Data Collected Carbon Estimates

Study Areas Pohnpei, Federated States of Micronesia Ding Darling National Wildlife Refuge, Florida, USA

Annual Landsat Mangrove Mapping and Assessment Continuous Change Detection and Classification (CCDC) 1985 2017 Landsat Time Series (WRS Path Row 16/42). CCDC uses all available Landsat data on a per pixel basis. Over 1,000 Landsat images were used in this analysis. Ding Darling National Wildlife Refuge, Florida, USA Citation: Zhu, Z., et al., 2012. Continuous monitoring of forest disturbance using all available Landsat imagery. Remote Sensing of Environment.122:75-91

Preliminary Results In August 2004, a Category 4 hurricane Change Detection in the Mangrove Ecosystem of J.N. "Ding" Darling National Wildlife Refuge, Florida (1985 - 2015) Year Total Mangrove Area (ha) Change in Mangrove Area 1985 1094.9 0.0 1986 1987 0.6 1988 1095.6 -1.2 1989 1094.4 0.3 1990 1094.7 1.4 1991 1096.1 0.5 1992 1096.7 -0.2 1993 1096.5 -0.9 1994 0.1 1995 1095.7 -0.1 1996 1997 1998 1095.5 0.4 1999 1095.8 0.2 2000 1096.0 -1.8 2001 1094.2 0.8 2002 1095.0 2003 1095.2 2004 1095.4 -45.8 2005 1049.6 2006 1050.9 -2.8 2007 1048.1 4.7 2008 1052.8 1.2 2009 1054.0 1.6 2010 1055.6 10.4 2011 1066.0 2.1 2012 1068.0 1.0 2013 1069.0 2014 1068.9 2015 1069.3 -1.3 2016 1067.9 -0.8 2017 1067.1 NA In August 2004, a Category 4 hurricane Charley slammed ashore a few miles north of Ding Darling NWR.

CCDC identified loss of forest due to hurricane Charley of 2004 as seen in year 2005. During field work our team identified dead trees as well as regrowth in these areas.

Field work to assess in situ biophysical characteristics Sampling Design Using results reported in Kaufmann and colleagues (2014) with allowable error of 0.2 it was determined that 23 transects should be sampled. Each transect consists of 5 consecutive plots with distance between them of 25 meters set perpendicular to the mangrove water ecotone edge. Each transects starts 15 meters away from the mangrove water ecotone border. Adapted from: Kauffman, J.B., and D.C. Donato. 2012. Protocols for the measurement, monitoring and reporting of structure, biomass and carbon stocks in mangrove forests In. Working Paper 86, CIFOR

Field Data ( 23 Transects established) Smith and Whelan (2006) developed allometric equations that were used to convert the biophysical data into above ground biomass for 3 primary species that occur in DD NWR, primarily based on the relationship of DBH to carbon stock. Preliminary Results

Carbon Estimates Preliminary Results 1. Biomass of plots Smith and Whelan (2006) developed allometric equations that were used to convert the biophysical data into above ground biomass for 3 primary species that occur in DD NWR, primarily based on the relationship of DBH to carbon stock. Carbon Estimates Preliminary Results 1. Diameter at breast height (DBH) 2. Allometric equations (from Smith and Whelan, 2006) 1. Biomass of plots 2. Proportion of mangrove biomass to carbon (~ 0.465) 3. Area of plots 4. Carbon density of plots ( 49.67 MgC/ha) 5. Hectares of mangroves in DD NWR in 2016 (~1067) Total Carbon stored as Above Ground Biomass in DD NWR (52,998 MgC)

Total mangroves on the island = 5000 ha. Pohnpei coordinates: 6.8541° N, 158.2624° E Why Pohnpei, FSM: FSM has a close relationship with the USA - DOI Office of Insular Affairs manages the Compact with FSM After 2nd world war the United States took over the island as a United Nation's Trust Territory.　 And finally in 1979, a federation was established between Pohnpei and the neighboring Trust Territory islands of Yap, Chuuk and Kosrae. These four islands became the Federated States of Micronesia, and in 1986 gained official independence when the US ratified the Compact of Free Association treaty.

High resolution map of the mangrove distribution

The total mapped area of Mangrove forest is 5,723 hectares. Landsat and SPOT satellites lack the detail and cloud-free coverage required for detailed mangrove mapping We used high resolution WorldView 2 (WV2) and Quickbird Satellite Imagery The results of this study are based on the accuracy assessment derived from the stratified random sample of 500 reference points. The overall accuracy of the mangrove map for Pohnpei was very high at 98.9 ± 1%. The total mapped area of Mangrove forest is 5,723 hectares.

Field work to assess in situ biophysical characteristics Sampling Design 𝐌𝐢𝐧𝐢𝐦𝐮𝐦 𝐧𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐬𝐚𝐦𝐩𝐥𝐞𝐬 𝐧 = 𝒕∗𝒔 𝑬 𝟐 Using preliminary results (carbon estimates and the standard deviation) from our study in Ding Darling NWR in Florida with allowable error of 0.2 it was determined that 39 sample transects will have to be sampled. A transect consists of consecutive points with distance between them of 150 meters. Distance between the rows and columns is set at 1.5 km. If the distance between two points is longer than 450 meters (three cells) than that is considered to be separate transect. There are 61 transects where some transects consist of 1 and some of 15 plots per transect. Adapted from: Kauffman, J.B., and D.C. Donato. 2012. Protocols for the measurement, monitoring and reporting of structure, biomass and carbon stocks in mangrove forests In. Working Paper 86, CIFOR Donato, D. and Mackenzie, 2010. Filed Protocol for Monitoring Ecological Function and Sea-Level Rise Impacts in Palau Mangroves

It takes a village to finish a transect

Capacity-building Workshop Above Ground Biomass Estimation   7-11 August, 2017 Pohnpei, Federated States of Micronesia

Future Research Accuracy Assessment of the Remote Sensing Results. Apply the developed methodology to other mangroves areas.