Mizuki Tomita

POST‐DISPERSAL CHANGES IN THE SPATIAL DISTRIBUTION OF FAGUS CRENATA SEEDS

The spatial distribution of tree seeds is influenced by the behavior of seed dispersers and seed-killing agents. In this study we evaluated the relative importance of multiple seed-killing agents on changes in the spatial pattern of Fagus crenata seeds. The dispersal of seeds and causes of seed death following dispersal were investigated on a 0.6- ha study plot in northern Japan. Seeds were collected using seed traps (n = 110) in the autumn of 1995, as well as directly from the AO layer of the soil, including leaf litter, intermediate, and humus layers (n = 110), in the spring of 1996. A total of 44075 seeds were disseminated into the seed traps, including 17 964 mature seeds; 15% of these were viable the following spring, indicating a large decrease in the abundance of viable seeds during the post-dispersal seed stage. Spatial association of undamaged seeds changed from a positive to independent association between the different dispersal stages, indicating rearrangement of the spatial pattern of seeds through time. During this period, numbers of living seeds generally decreased beneath nonspecific adults compared to those located away from the adults. This change resulted from the spatially different behavior of several biotic and abiotic killing agents. Rodents and fungi attacked the seeds, depending on seed densities and presence of nonspecific adult crowns, respectively, but desiccation was independent of both seed density and nonspecific crowns. The multiple killing agents with different spatial behavior jointly influenced the distributions of recruits entering tree populations.

Potential effects of climate change on geographic distribution of the Tertiary relict tree species Davidia involucrata in China

This study, using species distribution modeling (involving a new approach that allows for uncertainty), predicts the distribution of climatically suitable areas prevailing during the mid-Holocene, the Last Glacial Maximum (LGM), and at present, and estimates the potential formation of new habitats in 2070 of the endangered and rare Tertiary relict tree Davidia involucrata Baill. The results regarding the mid-Holocene and the LGM demonstrate that south-central and southwestern China have been long-term stable refugia, and that the current distribution is limited to the prehistoric refugia. Given future distribution under six possible climate scenarios, only some parts of the current range of D. involucrata in the mid-high mountains of south-central and southwestern China would be maintained, while some shift west into higher mountains would occur. Our results show that the predicted suitable area offering high probability (0.5‒1) accounts for an average of only 29.2% among the models predicted for the future (2070), making D. involucrata highly vulnerable. We assess and propose priority protected areas in light of climate change. The information provided will also be relevant in planning conservation of other paleoendemic species having ecological traits and distribution ranges comparable to those of D. involucrata.

Monitoring Landscape Changes in Japan Using Classification of Modis Data Combined with a Landscape Transformation Sere (LTS) Model

Abstract Japan, with over 75% forest cover, is one of the most heavily forested countries in the world. Various types of climax forest are distributed according to latitude and altitude. At the same time, human intervention in Japan has historically been intensive, and many forest habitats show the influence of various levels of disturbance. Furthermore, Japanese landscapes are changing rapidly, and a system of efficient monitoring is needed. The aim of this research was to identify major historical trends in Japanese landscape change and to develop a system for identifying and monitoring patterns of landscape change at the national level. To provide a base for comparison, Warmth Index (WI) climatic data was digitalized and utilized to map potential climax vegetation for all of Japan. Extant Land Use Information System (LUIS) data were then modified and digitalized to generate national level Land Use/Land Cover (LU/LC) distribution maps for 1900, 1950 and 1985. In addition, MODIS data for 2001 acquired by the Tokyo University of Information Sciences were utilized for remote LU/LC classification using an unsupervised method on multi-temporal composite data. Eight classification categories were established using the ISODATA (cluster analyses) method; alpine plant communities, evergreen coniferous forest, evergreen broad-leaved forest, deciduous broad-leaved forest, mixed forest, arable land (irrigated rice paddy, non-irrigated, grassland), urban area, river and marsh. The results of the LUIS analyses and MODIS classifications were interpreted in terms of a Landscape Transformation Sere model assuming that under increasing levels of human disturbance the landscape will change through a series of stages. The results showed that overall forest cover in Japan has actually increased over the century covered by the data; from 72.1% in 1900 to 76.9% in 2001. Comparison of the actual vegetation and the potential vegetation as predicted by WI, however, indicated that in many areas the climax vegetation has been replaced by secondary forests such as conifer timber plantations. This trend was especially strong in the warm and mid temperate zones of western Japan. This research also demonstrated that classification of moderate resolution remote sensing data, interpreted within a LTS framework, can be an effective tool for efficient and repeat monitoring of landscape changes at the national level. In the future, the authors plan to continue utilizing this approach to track rapidly occurring changes in Japanese landscapes at the national level.

Structure and diversity of remnant natural evergreen broad-leaved forests at three sites affected by urbanization in Chongqing metropolis, Southwest China

Evergreen broad-leaved forests (EBLFs, lucidophyllous forests) are vegetation types characteristic of East Asia. The extent of EBLFs has decreased significantly due to long-term anthropogenic disturbance, and remnant EBLFs in urban area are rare and important landscape types contributing to biodiversity and sustainable development. This study focuses on remnant EBLFs on Mt. Gele (GL), Mt. Tieshanping (TSP), and Mt. Jinyun (JY), located from the inner city to outskirts of Chongqing metropolis, Southwest China. Species of Theaceae, Lauraceae, Symplocaceae, and other families, which are essential floristic components of primary EBLFs, were still the main components at the three sites. GL and JY showed higher biodiversity, with richer heliophytes and shade-tolerant species, respectively. Castanopsis carlesii var. spinulosa was the sole dominant species at all three sites in woody layer, with codomination by Pinus massoniana and Cinnamomum camphora at GL and by Machilus pingii and Castanopsis fargesii at JY; these evergreen broad-leaved trees all showed inverse-J or sporadic-shaped size distribution with large numbers of small stems, but the conifer tree Pinus massoniana showed unimodal distribution with small stems at GL. The height growth of tree species, especially Castanopsis carlesii var. spinulosa, was increasingly restricted from JY to TSP to GL. Sprouting is an important life history strategy at community and population level, and differences were exhibited from GL to TSP to JY. A rural–urban gradient from JY to TSP to GL was indicated in this study. Species composition, biodiversity, and stand structure of these remnant EBLFs showed obvious differences along this gradient, and conservation responses to address the effects of urbanization need to be carefully considered.

Effects of management on vegetation dynamics and associated nutrient cycling in a karst area, Yunnan, SW China

The legacies of land use (such as plantations, pastures and coppices) in the Shilin karst area of central Yunnan, SW China have strongly influenced the plant communities’ structure, dynamics, species diversity, litter nutrients inputs, and soil chemical properties. To evaluate the effects of various restoration approaches on ecosystem recovery in the area, we analyzed vegetation characteristics of a Pinus plantation, natural successional plant communities (the shrubland, the secondary forest and the natural premature forest), and their leaf litter nutrients and soil chemical properties. The natural successional plant communities had better regeneration, higher species diversity, higher litter nutrient input, and higher soil fertility as compared with the Pinus plantation. The results indicate that the natural secondary succession facilitates regeneration to young and old secondary forests, promotes recovery of plant diversity and cycling of litter-soil-nutrients, yielding greater ecological benefits. The study will provide guidance for restoration of the vegetation and for forest management planning in this fragile mountainous ecosystem.

Landscape change and sustainable development in the Yangtze River basin, China

The Yangtze River, the longest river in Asia, has her source in the Tibetan Plateau area of Qinghai. From there the great river flows through Yunnan and Sichuan Provinces, collecting the waters of numerous tributaries along the way to the East China Sea. The river is 6380 km long and drains an enormous basin of 1.17 million km (Liu 2008). This drainage basin includes the great cities of Chongqing, Wuhan, and Nanjing, with the world famous port of Shanghai at the mouth. The basin is also home to largescale wet rice cultivation. Rice cultivation in the region has a history that can be traced back to 7700 BC (Zong et al. 2007). Civilizations along the Yangtze, which over the millennia have rivaled those of the Yellow River Basin, are in recent years catching the attention of historians and archeologists. Also, high levels of nutrients, in waste water from the cities, as well as in agricultural chemicals from the rice paddies, enter the river system and are washed into the East China Sea. The middle reaches of the Yangtze are situated in the same evergreen broad-leaved forest zone as southern Japan (Kira 1991). As is the case in many parts of this zone, a long history of intensive land use and dense populations has brought great pressure on the local forest resources, and natural old-growth forests remain only in limited areas (Song and Cheng 2007). Most of the forest cover is now secondary in nature. In some spots, over-intensive harvesting has stripped the mountainside of vegetation, leading to soil erosion during heavy rains. The Yangtze River basin contains densely populated urban areas. On the outskirts of these cities, many rice paddies are being converted to vegetable farms. As urbanization and industrialization progress, new residential, commercial, and industrial complexes are being developed. Economic development, however, has not been even throughout the entire region. The eastern coastal area, centered on Shanghai, has developed rapidly, while the inland areas to the west have lagged behind. To rectify this imbalance, China began an ambitious and huge Western Region Development Project in 1999. The chief goal of this project was to narrow the gap in regional development, but protection of the environment and natural ecosystems, which in the western region have been deteriorating, was also stated to be a major concern (Xiang 2007). Of special importance is the Three Gorges Dam in Hubei Province along the middle reaches of the river. This dam began holding water in 2003, and is expected to have a major impact not only on ecosystems along the river, but on the East China Sea as well (Wu et al. 2004; Yang et al. 2011; Xu et al. 2013). This collection of research focuses first on fine scale analyses of the current status and directions of change for vegetation in the region’s agricultural landscape. Vegetation and environment in the cities of Shanghai and Chongqing are also investigated. Next remote sensing is employed to give a broad-scale feel for the impact that changes in the Yangtze River are having on the environment of the East China Sea and on the whole of East Asia. K. Hara (&) M. Tomita Department of Informatics, Tokyo University of Information Sciences, 4-1 Onaridai, Wakaba-ku, Chiba 265-8501, Japan e-mail: hara@rsch.tuis.ac.jp

Influence of Large Seasonal Water Level Fluctuations and Human Impact on the Vegetation of Lake Tonle Sap, Cambodia

Lake Tonle Sap, the largest inland water body in Southeast Asia, encompasses unique ecosystems and wildlife adapted to large seasonal fluctuations in water level. The permanent waterlogged area of the lake is encircled by a vast floodplain, the inundated woodland being dominated by Barringtonia acutangula (Lecythidaceae), probably a major vegetation type of this ecotone, although human impact has degraded the floodplain vegetation and developed forest is restricted to a narrow band along the shore in the lowest water season. The aspects of seasonally inundated vegetation (i.e., variations in physiognomy, species composition, stratification, and distribution) on the coastal side of the floodplain (approximately 4 km in depth), located adjacent to the southern part of Siem Reap, was analyzed. Quantitative data for phytosociological evaluation were collected at 67 quadrats (10 m × 10 m each) during the low water seasons in 2005 and 2006, the sampling plots being classified by Two- Way Indicator Species Analysis (TWINSPAN) and ordinated by Detrended Correspondence Analysis (DCA). Two vegetation zones (i.e., extensive cropland and disturbed woodland), seven vegetation types (i.e., “Cultivated field,” “Fallow field,” “Shrub,” and “Tall-shrub” in the extensive cropland zone and “Scrub,” “Open forest,” and “Closed forest” in the disturbed woodland zone), and vigorous invasion and/or regeneration of Barringtonia acutangula over the study area were identified. Human impact (e.g., plowing, burning, and cutting for firewood) seemed to be inversely related to both duration of flooding and maximum water depth and to be the main cause of degradation of seasonally inundated vegetation.

Impact of the Great East Japan Earthquake and Tsunami on Coastal Vegetation and Landscapes in Northeast Japan: Findings Based on Remotely Sensed Data Analysis

The Great East Japan Earthquake of 11th March 2011 and subsequent huge tsunami caused widespread damage along the Pacific Ocean coast of eastern Honshu, Japan. This research utilizes field surveys and analyses of multi-resolution remote sensing images to clarify the impact on landscapes caused by this disaster and also to monitor the subsequent survival and recovery process in the Sendai Bay region. MODIS data (250 m resolution) were employed to map the overall extent of inundation and damage on the regional landscape scale. The major damage caused by the tsunami, destruction of coastal pine forests and inundation of rice paddies on the plain, was identified at this level. Progressively finer-scale analyses were then implemented using SPOT/HRG-2 (10 m resolution) data, GeoEye-1 fine-resolution data (0.5 m), very fine-resolution aerial photographs (10 cm) and LiDAR. These results demonstrated the minute details of the damage and recovery process down to the level of individual groves and trees. The results of the research show that on the wide-scale regional level, plant communities on rocky cliffs along the rias-style Sanriku Coast survived relatively intact, but coastal forests and other vegetations on sandy beaches and other low-lying coasts were severely damaged. Finer-scale analyses of a coastal pine forest in the Sendai Bay area showed that local topography influenced the patterns of damage and survival for individual trees. At the finest level, damaged pine forests and sandy beach vegetation could be seen recovering only a little more than a year after the disaster. Continuous monitoring using fieldwork and remote sensing is required for balanced regional strategies that provide for economic and social recovery as well as restoration of vegetation, biodiversity and vital ecotones.

Effects of natural and artificial disturbance on landscape and forest structure in Tiantong National Forest Park, East China

This paper aims to understand the ecological effects of disturbance on broadleaved evergreen forest in East China. We used a manipulative field experiment approximating the common natural and artificial disturbance types in this area to investigate the community physiognomy, floristic composition, and 5-year recovery dynamics of the post-disturbance forest community. The results indicated that the landscape and forest structure have degraded into shrub communities, structure-damaged evergreen broadleaved communities, and so on. The post-disturbance communities presented different means of plant recruitment and vegetation recovery patterns at an early successional stage. The recovery of disturbed forests primarily depended on external seed sources and re-sprouting from stumps, rather than on soil seed banks, as few buried seeds were found. Re-sprouting thus appears to be key in allowing rapid vegetation recovery in evergreen broadleaved forest. Disturbances seem to be one of the most important factors that can contribute to regional species coexistence across temporal and spatial scales in evergreen broadleaved forests.

Multi-Scale Effect on Landscape Pattern Analysis Using Satellite Data with a Range of Spatial Resolutions

Multi-Scale Effect on Landscape Pattern Analysis Using Satellite Data with a Range of Spatial Resolutions In recent years, identifying the relationship between pattern and scale has emerged as a central issue in ecology and geography. Scale has been defined by grain or resolution but bias in results will occur if the scale is wrongly selected relevant to the landscape evaluation. In this research, satellite data of varying resolution, QuickBird (2.5m), ALOS/AVNIR-2 (10m), Terra/ASTER (15m) and Landsat/ETM+ (30m), were employed to analyze the scale effects of grain size. The research was implemented at Azeta, a typical rural landscape located in Sakura City, central Japan. Land-cover classifications were first implemented using the Maximum Likelihood Method on satellite data of varying resolution. Based on the results of these classifications, a number of landscape metrics imbedded in the FRAGSTATS were extracted for landscape pattern analysis. The results indicate that most landscape patterns show some degree of consistency and scaling relations such as power-law among the various satellite resolutions. The applicability of these various satellite data resolutions for landscape analysis in the target area was also evaluated.