【Spring Has Arrived by the Sea and Rivers】A 30-day trip to explore the living fossils – Davidia flowers in Nayong, Guizhou

It’s such a large fern – can it be used as a bonsai?

The lush vegetation – can you tell it’s full of moisture?

A simple wooden bridge over the stream, just a few pieces of wood put together – is that considered authentic? ?

Geological foundation: The geological structural unit in which the Guizhou Nayong Davidia involucrata Provincial Nature Reserve is located is the southern edge of the Beijie northeast-oriented structural deformation within the Northern Guizhou Platform. It is characterized by the development of flat-topped mountains and platform-like mountains (or Karukwagat karst cap mountains). The Permian and Triassic strata are exposed within the reserve, with complex lithological variations; there are significant differences in the lithology of the strata in the eastern and western sections. The geological structure in this area is complex, with well-developed faults and folds, among which northeast-east trending strike-slip faults play a prominent role. Geological Overview: The Guizhou Nayong Davidia involucrata Provincial Nature Reserve is located in the area between the Liuchong River and the Sancha River, upstream of the Wujiang River. Its elevation ranges from 1600 to 2200 meters above sea level, with a relative elevation difference within the reserve of 400 to 600 meters. The watershed between the two rivers runs through the southern part of the reserve, extending in an east-west direction in a winding pattern along Jinzhulin, Pingshangzi, Sanchahe, and Zhongling. The elevation there is generally >2000m; the highest point in the eastern area of Siling Mountain is 2217m, while the highest point in the western area of Zhongling is 2331m. The reserve features two main geomorphic types: karst and erosion-denudation, which are distributed intermingled with each other. The karst landforms in the eastern part are widely distributed. The dominant landform patterns are karst peak clusters and depressions, as well as peak cluster mountains; karst valleys and depressions are also well-developed in this area. Erosional funnels, caves, underground rivers, and phreatic streams can be seen frequently there. Between the karst landforms, there are tall eroded and denuded mountain ridges, among which those in the areas of Siling Mountain and Dapingqing are particularly widespread. Eroded and denuded mountainous areas are widespread in the western region, interspersed with tall karst cap mountains – karst peak forest landforms that cover the tops of these eroded mountains; examples of such are the karst peak forests along the cliffs in the Shangmuqing and Mahuangqing canyons. Hydrology and water quality; Water resources. The Guizhou Nayong Davidia involucrata Provincial Nature Reserve is located in the interfluve area between the Liuchong River and the Sancha River. The catchment areas in the river’s source regions are small, which is why the rivers are relatively short. To the north of the watershed, the Nayong River and the Mucheng River flow; the lengths of these rivers within the area are approximately 21 km and 16 km respectively. They flow northward and eastward to merge into the Liuchong River, with their drainage basins covering more than 80% of the area of the protected zone. To the south of the watershed, the Mahuangqing River is the main watercourse; it is approximately 12 km long within this area and flows southward to merge with the Sancha River. The rivers in these protected areas are all rain-fed, have a large hydraulic gradient, and exhibit hydrological characteristics of sudden rises and falls in water levels. Based on regional hydrological data, the average annual runoff modulus for this area is 18.9 L/S.km2, and the average annual runoff depth is 596 mm. Within the Guizhou Nayong Davidia involucrata Provincial Nature Reserve are the Diaoshuiyan Reservoir and the Dahuiba Reservoir. The Diaoshuiyan Reservoir has a storage capacity of 2.5 million m3 and a water surface area of 239,760 m2 ； Diaoshuiyan Reservoir serves as a backup water supply source for domestic use in the urban area of Nayong County. The Dahanba Reservoir has a storage capacity of 385,000 m3, with a water surface area of 31,434 m3 ； The Da Daba Reservoir is primarily used as a water source for irrigating farmland. Regarding water quality, chemical analyses of water samples taken from the main water sources such as Diaoshuiyan Reservoir and Dahaiba Reservoir within the Guizhou Nayong Davidia involucrata Provincial Nature Reserve, conducted by the Water Environment Monitoring Center in Bijie Prefecture, Guizhou Province, show that there are no pollutants in the water samples from this nature reserve. The pH value of the water is around 7.0; there are no natural sources of pollution. The water is colorless, odorless, clear, and transparent. None of the major pollutants found in natural water resources, such as iron, manganese, mercury, and biochemical oxygen demand over a five-day period, exceed the specified standards, meeting the Class II water quality standards set out in the “Surface Water Environmental Quality Standards” GB3838—2002. Climate conditions: The Guizhou Nayong Davidia involucrata Provincial Nature Reserve is located in the north subtropical plateau humid monsoon climate zone, while the mountainous areas at an altitude of over 1,800 meters fall under the warm temperate plateau humid monsoon climate zone. The average annual temperature ranges from 10.4°C to 15.1°C, with the highest annual temperature reaching 35.6°C and the lowest at -15.1°C. The effective accumulated temperature above 10°C is 4062°C. In winter, rain, snow, and freezing are severe. The annual average absolute humidity in this area ranges from 9.9 to 14.8 hpa, while the annual precipitation amounts to 1062.1 mm to 1440.0 mm. The annual distribution of precipitation is uneven, with the highest amounts falling between April and September, accounting for 80% to 86% of the total annual precipitation, and heavy rains occur frequently during this period ； Winter sees the least rainfall, accounting for only 32.5% to 54.9% of the annual total. These climatic characteristics result in abundant surface and subsurface runoff in the region, with significant seasonal variations in the natural replenishment of water resources. The wind direction is influenced by the atmospheric circulation; in the winter half of the year, northeast and northward winds predominate, accounting for 30% of the total wind directions throughout the year ； In the summer half of the year, south winds and southwest winds predominate, accounting for 25% of the cases ； The still wind frequency accounts for 36%. Soil conditions: The parent rocks of the soil in the Guizhou Nayong Davidia involucrata Provincial Nature Reserve are sandstone shale and carbonate rocks. The soil is mainly yellow soil, with small amounts of yellow-brown soil and purple soil. Its distribution characteristics are as follows: the ridges are mostly silico-ferrous yellow soil, which is heavy in texture; the pH value ranges from 5.5 to 7.0, and the thickness of the soil layer is about 0.5 meters. In some areas with erosion gullies and low-lying zones, this thickness can exceed 1 meter ； The middle and upper parts of the mountains are mainly characterized by silico-aluminous yellow soils; the soil profile structure there is relatively intact, making these areas the main zones for the growth and development of trees within the reserve ； Purple soil patches are embedded within them, mostly found in areas where carbonate rocks are exposed, and the soil layers are relatively infertile. The soils in the small lake and dam areas of the protected zone are mainly acidic, with a pH value ranging from 3.72 to 5.44, and an organic matter content of 13.8–79.7 g/kg ； The soil in some areas is acidic, with a pH value of 5.5–6.5 and an organic matter content of 5–75.9 g/kg ； In other areas, the soil is neutral, with a pH value of 6.5–7.5 and an organic matter content of 2.9–75.9 g/kg. The soil in the Shanshanqing area of the Guizhou Nayong Davidia involucrata Provincial Nature Reserve is mostly humus soil; it belongs to the yellow soil type, with a pH value of 5.5–7, indicating a slightly acidic environment. The organic matter content ranges from 22.7 to 45.7 k/kg. The parent material of this soil is loess, and it has good drainage properties. There is a small amount of yellow-brown soil, with a pH range of 3.5 to 7.5; most of the soil is strongly acidic or acidic, while a small portion is neutral. The organic matter content ranges from 2.9 to 75.9 g/kg. The parent materials of this soil are loess, colluvium, and residual sediments of sandstone, and it has good drainage properties. Air quality: According to the monitoring results of the environmental quality in Nayong conducted by the Bijie Environmental Monitoring Station, the hourly average concentration of sulfur dioxide (SO2) in the ambient air of the Guizhou Nayong Davidia involucrata Provincial Nature Reserve is 130–150 μg/m3, while the daily average concentration is 20–45 μg/m3 ； The hourly average concentration of nitrogen dioxide (NO2) is 178–190 μg/m3, and the daily average concentration is 60–75 μg/m3 ； The daily average concentration of carbon monoxide (CO) is 3.88–3.96 mg/m3 ； The daily average concentration of inhalable particulate matter (PM10) is 38–45 μg/m3 ； The daily average concentration of total suspended particles (TSP) was 108–113 μg/m3. All the above indicators meet the first-class standards specified in GB3095-2012 \"Environmental Air Quality Standards\". The forest coverage rate in the Guizhou Nayong Davidia involucrata Provincial Nature Reserve is 71.5%, and the air there is pure and fresh. According to monitoring results, the average concentration of negative oxygen ions in the air of this reserve is around 5,000–35,000 per cm3, making it a veritable natural oxygen bar.

Within Nayong, the **Class I protected plant – Davidia involucrata** occurs naturally over an area of 7,120 hectares, with a population of nearly one million plants. In January 2013, Nayong submitted documents to the China Wild Plant Conservation Association to apply for the title of \"Hometown of Davidia in China\". The Nayong Davidia Provincial Nature Reserve is a wildlife conservation area whose main purpose is to protect **first-class protected rare plants** such as the smooth-leaved Davidia, Yun Gui water fern, and Decapetalum, as well as their habitats. The nature reserve is located in the southern part of Nayong County, with a total area of 11,398.22 hectares. Of this, the core area covers 4,565.57 hectares, the buffer zone covers 2,293.13 hectares, and the experimental area covers 4,539.52 hectares. The core distinction lies in the four areas of Shanmuqing, Doupoqing, Cichong, and Bailedaqing. While establishing the Davidia involucrata Nature Reserve, Nayong County has stepped up its promotional efforts to further establish its reputation as the \"Hometown of Davidia involucrata in China,\" thereby promoting the development of an ecological civilization in the area and adding a beautiful \"landscape\" to the Bijie Pilot Zone. It is understood that the Davidia tree is a deciduous tree. It can grow to 15–25 meters in height, with broadly ovate leaves that have serrated edges. The genus of these plants contains only two species: one with hairy leaves and the other with smooth leaves. The Davidia flower is extremely beautiful in color. It is a relic plant that dates back to the Tertiary period of the Cenozoic era, 10 million years ago. During the Pleistocene ice ages, Davidia species disappeared from most areas, with only a few surviving in southern China, thus becoming what are known today as \"living fossils\" in the world of plants. It is referred to as the \"Pigeon Tree of China\" or also as the \"Pigeon Flower Tree\". The Davidia tree has been classified as a **wild plant under first-level protection, and it is also a renowned ornamental plant worldwide. On April 12, 2013, Yu Yongfu, a section chief from the China Wildlife Conservation Association, Yu Shengxiang, a professor at the Institute of Botany, Chinese Academy of Sciences, and Zhang Huahai, the deputy director of the Guizhou Province Wildlife Management Station, went to Nayong together to investigate the Davidia involucrata resources and conduct another count to confirm their numbers. On June 3, 2013, the China Wild Plant Conservation Association officially issued a document granting Nayong the title of “Home of the Davidia in China”. “\"The Home of Davidia in China\" has caught the interest of many foreign investors, who have come to Nayong to conduct inspections and make investments. Tens of thousands of tourists came to see the Davidia trees, boosting tourism revenue to new levels and thus opening the way for the development of ecological tourism in Nayong. 【Print main text】