Maorui Branch of the Management Office of Hainan Tropical Rainforest National Park is located in the junction to the northwest of Baoting County, southeast of Ledong County and southwest of Wuzhishan City. The area (109°23'28"E-109°34'34"E, 18°36'32"N-18°41' 36"N) occupies a total area of 368 square kilometers.

Maorui is 9.3 kilometers away from Mao’an, Baoting County, along the Haikou-Yulin Highway, 34 kilometers away from Baoting County, and 22 kilometers away from Wuzhishan City. Mountains and hills take up most of the area, with an average elevation of 450-600 meters. The highest peak MaZui Ling stands as tall as 1,317 meters, followed by the YaRi Ling (1,284m), FuNong Ling (1,037m), GeFen Ling (1,223m), FenJie Ling (1,207m) and Qin'AI Ling (880m).

The Maorui area is located in the southwest offset of WuZhi Shan range and the migmatitic granite hilly area of the southern Hainan Island. It is a moderately cut dome mountain formed by erosion and denudation. The area is surrounded by high mountains on all sides, with a long and narrow exit along the river to the North. The elevation is mostly between 450 and 600 meters. The highest peak is MaZui Ling (1,340 meters) and the lowest point lies at the North access (410 meters).

Climate and hydrology

The low-latitude Maorui area has tropical marine monsoon climate featuring long sunshine duration, sufficient heat, mild climate, warm winters and cool summers. Warm and humid air transported from Southeast China results in abundant precipitation, frequently in the form of typhoon rain. The onset and retreat of rainfall comes quickly in the area, which is broken up in two main seasons, dry and wet. From May-October (summer half-year), the region is mainly affected by the southwest monsoon, the equatorial convergence belt, typhoon and other tropical circulation weather systems. At that time, it is humid, hot and rainy. From November to April (winter half-year), it is dry and cool, with occasional short cold spells and low amount of precipitation. In the Maorui area, the total annual solar radiation reaches 133 kcal/cm²; the average annual sunshine duration lasts 2,016 hours; the average annual temperature is 22.9 ℃; the average temperature in the coldest month (January) stands at 16 ℃, and the figure rises to 27.6 ℃ in the hottest month (July), with a temperature difference of 11.6 ℃; the annual rainfall is above 1,900 mm; the annual evaporation is about 1,700 mm; and the annual average relative humidity is 83.9%. Typhoon, rainstorm, droughts, low temperature and overcast rainy days are the major weather disasters in the region. Typhoon appears more frequently and affects the area for longer time, while droughts often occur in spring. In addition, the microclimates in different parts of the Maorui area also come in various forms.

Within the Maorui area, Hongshui River joins Maoqing River and flows across Baoguo River, the Changhua River and eventually into the South China Sea. The sections of rivers running through the area are short, and the slope of river bed is large, of which water level decreases or increases sharply. This results in poor water regulation and storage, as well as great difference of the water flow between floods and droughts. Water systems cover an area of 8.5 hectares, accounting for 0.36% of the total area of Maorui. And the abundant water in the area enjoys good quality, identified as Class I by the Surface Water Environmental Quality Standard (GB 3838-2002).

Plant resources

Statistics show that there are 1,299 species of spermatophyte in 633 genera and161 families in the Maorui area, accounting for 41.24% of the recorded plant species in Hainan. Among them, 15 species (7 genera and 6 families) are gymnosperms, 1,165 species (541 genera and 136 families) are dicotyledon plants in the angiosperm community, and 119 species (85 genera and 19 families) are monocotyledons. The richness of plant species indicates that Maorui functions as an important part of the flora of Hainan Island.

There are 15 species of national key protected wild plants in Maorui, of which 3 species, including Cycas rumphii, are Class I national key protected wild plants and 12 species (e.g. Madhuca hainanensis, Alseodaphne hainanensis Merr., Dalbergia odorifera and Vatica mangachapoi ) are Class II national key protected wild plants. There are 171 plant species endemic to Hainan, accounting for 33.86% of the native species in Hainan. These include but are not limited to Cycas hainanensis, Polyalthia laui Merr., Cryptocarya impressinervia, Cyclea hainanensis Merr., and Impatiens hainanensis. The Maorui area has 3 vegetation-type groups, 6 vegetation types and 10 formations. The typical zonal vegetation from bottom to top is tropical moist rainforest, tropical montane rainforest and tropical montane elfin forest. Except for natural forests, there are also artificial vegetation species such as Caribbean pines, eucalyptuses, rubber, and betel nut palms.

Animal resources

Statistics and historical records suggest that there are 239 species of terrestrial vertebrates in 82 families (26 orders of 4 classes) in Maorui. These include 14 species of amphibians in 5 families (1 order), 41 species of reptiles in 11 families (2 orders), 130 species of birds in 45 families (15 orders), and 54 species of mammals in 21 families (8 orders). In particular, 3 species are Class I national key protected wild animals, 31 Class II national key protected wild animals and 10 endemic to China. In addition, the Maorui area is home to 143 terrestrial wild animals that are beneficial or of great economic and scientific value in China and 51 listed as key protected territorial wild animals in provincial level. Among 39 CITES-listed species in the area, 4 are listed on Appendix I, 30 on Appendix II and 5 on Appendix III. About 71 species found here have been included into China’s Red List of Biodiversity, including 6 CR species, 15 EN species, 16 VU species and 34 NT species. 18 bird species are included in the agreement concerning the protection of migratory birds, which was signed by Japan and China in 1981, and 5 species included in the similar agreement between China and Australia in 1986.