【導(dǎo)讀】QUANBin,CHENJian-Fei,QIUHong-Lie,M.J.M.ROMKENS,YANGXiao-Qi,JIANGShi-FengandLIBi-Cheng'oftheearth.

　　

【正文】 luan Bay, not only increased the potential of flooding during tides, but also raised the possibility of saltwater intrusion from the sea. As a matter of fact, the sealanes became shallower and flooding hazards increased. The practice of reclaiming land from the sea has therefore posed a strong threat to the marine environment and has disturbed the balance of the marine ecosystems. In short, parative economic benefits for the farming population and public policies were the main driving forces for water body changes. Tree cutting and the expansion of orchards were the main reasons for the decrease in forests in Xiamen. Xiamen climatic conditions are often referred to as the ??the four evergreen seasons”, which means that they are favorable for growth of various mercial crops. These mercial crops have had a long history as well as large market potential and economic benefits for its population. Since the 1 9 8 0 ~due to the favorable climatic resources and population growth orchard development has taken place rapidly (Figs. 1 and 2). Another reason for the decrease in forest area was serious deforestation. In July 1998, the Xiamen Municipal Government issued measures for forest preservation. These measures stipulated that activities destroying the forest, which at the time consisted of random and unauthorized reclamation。 excavating stone, sand, and soil。 mining。 and tomb and house building, were prohibited. After the corrective measures were put into practice, the cutting of forest by farmers gradually decreased. However, during the period of 19982021, the expansion of orchards and ruralurban industrial land contributed more to forest decrease than cutting forests. That is the reason why the average annual loss for the forests in 19881998 was ha while in 19982021 it was about ha (Table I). Therefore, forest preservation is still an important issue in Xiamen and should be paid more attention. Orchard and forest change. Strategies for sustainable land utilization A balance between economic growth and cropland utilization was necessary. In Xiamen, urbanization has been the result of economic development with the expansion of urban areas leading to elimination of large areas of cropland. Thus, a reasonable plan for converting cropland, especially for building sites, was necessary. Some measures, such as keeping the total amount of cropland unchanged and changing other land use types, were considered. Meanwhile, because many farmers constructed their private homes on high quality agricultural production land, law enforcement needed to be strengthened. Moreover, a decision support system and dynamic monitoring system of land utilization should be established and the total amount of land supply should be strictly controlled (Dung and Sugumaran, 2021). From the perspective of harmonizing economic development and land use, it was necessary to innovate a policy for cropland conservation. For example, a “cropland replacement policy” could be adopted, which should permit a proportion of additional cropland to be developed for urbanization and industrialization purposes, but this would require the conversion of other land use types to cropland elsewhere and/or making expenditures for additional cropland development. It has also been suggested that a more responsible system identifying basic farmland, and permit policies for basic farmland should be developed. The ultimate aim was to keep the economy growing all the time. Nevertheless, the phenomenon of replacing fertile cropland with inferior land should be forbidden (Zhao, 2021). The potential of the land resources needed to be fully tapped. Xiamen belonged to a region in China, where water, heat and light resources were most abundant. This potential could be fully tapped. Because of light energy conditions, a more rational arrangement of the different plant varieties would allow an increase in agricultural primary productivity (Bao et al., 2021). There have been many instances of intercropping or mixed cultures, which could raise land productivity. Besides, it was important to build up a rational food chain work so that the byproducts of one anism could be used as the food source for another (Zhu, 1997 and 2021). Heat energy was also favorable. Subtropical fruits made better use of the heat and grew well The establishment of a fruitfarminggrassstock breeding plex system was another useful ecological pattern of agriculture that has been designed and popularized. The result of this ecological experiment showed that the total energy output per unit area was times that of the traditional system. This ecological friendly system showed a benign circulation in the production process that had favorable ecological and economic benefits, and offered wonderful prospects (Zhu and Cheng, 2021。 Quan et al., 2021). Though Xiamen has two or three harvests per year, presently the multiple crop index is only about 210%. As a result, the develop potential to further raise the multiple crop index was great. The drought during the summer and autumn was due to unequal distribution of rainfall in time and space. The soil water volumetric capacity, waterstorage capacity, especially the available waterstorage capacity in lateritic red soil was small and the water content available for plant growth was limited. These conditions promoted the progressive development of drought. Installation of irrigation equipment and the development of sprinkling and trickle irrigation could effectively increase water use efficiency in lateritic red soil during the dry season. Owing to various problems in large scheme, small irrigation schemes are considered more suitable to develop at present (Wakatsuki and Masunaga, 2021). Soil mulch was also necessary to preserve soil water (Quan et al., 2021a and 2021a). Additionally, the wi