Remote sensing of ecosystem dynamics plays an essential role in the intelligence, i.e., data collection, analysis, diagnosis, prediction and decision making, for food and environmental security. A wide range of signatures in optical, thermal and microwave domains are now available from spaceborne, airborne, and ground-based sensors. Spatio-temporal data over ecosystems can be acquired at various spatial, temporal, and spectral resolutions. A number of statistical and physically-based methods have been devised to utilize remotely-sensed signatures for agricultural and ecosystems applications. This review overviews the state of the art in remote sensing of ecosystems for food and environmental intelligence, and discusses the future direction of national and international efforts to monitor, diagnose and care the terrestrial ecosystems. It is strongly suggested to construct inter-discipliary, inter-agency, and international networks for ecosystem intelligence.
Vegetation cover change has been reported to occur over large areas in the southern Legal Amazon due to extensive cattle ranching and large-scale mechanized agriculture since the early 1980s. In this paper, we aim at doing more detailed analysis for the terrestrial features of deforestation and savannization in these areas, using by integrating remote sensing data with cattle ranching and cropland area data at municipal districts levels on a GIS platform. We clarify that the terrestrial features depended on an advance of cattle ranching and Corn production in northern part, Soybean production in central and west Mato Grosso and much agriculture and cattle business in the south using GIS and the 5-year Digital Vegetation Model Maps built for every 5-year period between 1981 and 2001 by NOAA/AVHRR multi-spectral data. This paper suggest clearly terrestrial features of deforestation and savannization in each municipal districts. Cattle ranchers or corn cropland in northwest Mato Grosso and soybean cropland in the central have been the main contributor to most of deforestation in tropical rainforests. And savannization by soybean cropland spread mainly in the west and by corn in the southeast. Corn productions have more savannization impacts than the soybean crop production. All these findings highlight the non-sustainable processes of resources development occurring not only in Mato Grosso state, but also over the all Amazonian tropical rainforests region.
The authors try to produce landscape ecological maps for estimation of biodiversity using airborne laser survey data (LIDAR data). A studied area is north foot of Mt. Dougo, Chugoku Mountains, as a ‘Satoyama’ rural area. Basic legend of landscape ecological map consists of the combination of three dimensional vegetation structure classification using detailed DSM (Digital Surface Model) and micro landform classification using detailed DEM (Digital Elevation Model). As LIDAR data is useful for detection of micro landform under forest area by using last pulse data in autumn season, automatic landform classification was done using autumn season DEM. Vegetation classification was done using three dimensional vegetation structure detected by the difference between DSM data in two seasons. In addition, many kinds of field surveys were carried out for ground truth of such as vegetation survey, measurement of forest structure and geological survey. As the results of overlay analysis of LIDAR vegetation maps and automated landform classification maps, it has become clear that J. mandshurica are dominant in historical iron sand mining (Kanna-Nagashi) site on Mt. Dougo.
Ecosystem carbon stock is an important pool in global carbon cycle, and is seriously affected by land-use and management practices. The slash-and-burn cropping is widely practiced in the tropical mountains in Southeast Asia. Drastic land-use change in slash-and-burn ecosystems in mountainous mainland of Southeast Asia would strongly affect the food security, resource sustainability and global environment. Nevertheless, quantitative information has been scarcely available for the region. This study assessed the regional ecosystem carbon stock based on synergy of chrono-sequential analysis of satellite imagery and in situ measurements of carbon in the soil and fallow vegetation. Results suggested that the ecosystem carbon stock would continue decreasing under the present land-use condition with short fallow cycle, but also that both food security and ecosystem carbon stock would be increased by altering land-use/ecosystem management scenarios.
Increase in abandoned agricultural lands is a big problem in Japan. Satellite remote sensing is one of promising approaches for periodic monitoring of the abandoned agricultural lands with low cost. We developed a method of detection of abandoned rice paddies with satellite data and evaluated it with ground observation data. We found that the difference of NDVI between a rice paddy and an abandoned rice paddy was particularly large in one month of just after planting as well as two months of just after harvesting. By taking advantage of this feature, we produced the map of abandoned rice paddies by using ALOS AVNIR-2 data taken in the post-harvest period. Error matrices were produced to evaluate some accuracies : Producer's accuracy for abandoned rice paddies was 71.8%, and user's accuracy for abandoned rice paddies was 86.1%. Although most of the previous studies used only satellite data taken in the post-planting period, this study shows utility of satellite data in the post-harvest period.
The objective of this study is to monitor the Trophic State Index (TSI) in six typical eutrophic lakes in Japan (Lake Shinji, Lake Nakaumi, Lake Kojima, Lake Biwa, Lake Suwa, and Lake Kasumigaura) using 500-m resolution MODIS data provided from JAXA. As a result, the following matters were clarified. 1) A strong correlation except for some data (e.g. turbid conditions) between 500-m resolution MODIS chlorophyll-a (Chl.a) and in-situ Chl.a was observed (R=0.76, RE=15%). 2) Monthly Chl.a change pattern of 500-m resolution MODIS Chl.a and in-situ Chl.a in 2008 corresponded very well. 3) Chl.a in brackish Lake Shinji and Lake Nakaumi was convertible in T-P and T-N as well as these in the freshwater lakes. 4) Yearly average TSI of Lake Kasumigaura was the highest, and that of Lake Biwa was the lowest in six lakes. 5) High level TSI (Chl.a) that exceeded pattern III corresponding to Japanese environmental standards of T-P and T-N was estimated in Lake Kasumigaura and Lake Kojima. 6) There are three main problems for TSI monitoring using MODIS data in “accuracy of MODIS Chl.a”, “satellite sensor resolution”, and “system of the in-situ observation and vertical Chl.a modeling”. However, TSI using 500-m resolution MODIS was a very useful monitoring method for eutrophic lakes.
The coral reef environment has turned worse on a global scale and reefs of the Okinawa islands are no exception. Although it is generally accepted that the main cause of coral degradation is related to rise and fluctuation of sea surface temperatures driven by the global warming, a coral reef ecosystem could also be disturbed by a variety of extremely local ecological and/or anthropogenic influences, resulting in coral bleaching and drastic population decrease. The aim of this study is to make clear the process of changes in the shallow-water coral reef environment with regard to land use alterations in the area of Shiraho on Ishigaki Island located in Okinawa, south west of Japan. Okinawa, a former Japanese territory under the U.S. administrative authority following the World War II, was returned to Japan in 1972. Thereafter, Okinawa was incorporated in the Japanese economy under the three Okinawa Development Plans in order to rapidly accomplish the social transformation. In Okinawa, several land improvement projects were performed under these development programs, followed by large-scale topographic changes accompanying extensive deforestation and sudden changes of land use practices. As a result, red soil outflow, overloaded runoffs from the farmlands, eutrophication, environmental perturbations of shallow-water reef ecosystems and quasi-extinction of hermatypic corals occurred. In this study, the impacts of the development process on the island ecosystem were assessed by examining the changes in the land use patterns on the island after 1972. Furthermore, using seven series of aerial photographs taken after 1972. I investigated the relevance of the changes on land areas to the deterioration of Shiraho coral reefs. The ratio of the sea grass bed colonizing the coral reef moat in 1972 was only 1.2%. After about 30 years (2004), the sea grass bed spread over 7.5% of the same area. The sea grass bed spread most extensively in the place adjacent to land improvement projects where large accumulation of red soil and nutrients took place. The combination of the impact of land improvement projects, the excrement of artificial manure and the runoff flow to the lagoon from the beef cattle breeding caused the spatial extension of the sea grass bed. Because the growth of sea grass is faster than that of hermatypic corals, the hermatypic corals lose their habitat as seaweeds spread.