Seed plant diversity of different forest types in Liangshui National Natural Reserve

Abstract Background Thirty years ago, there was a monograph of vegetation and plant diversity in the region prepared by the Department of Forestry at the Northeast Forestry University (unpublished), but the variety of plants in the region has changed significantly over the past 30 years. In future years, the authors hope to publish a new monograph and this research is to prepare for this work. This study aimed at reporting the characteristics of plant diversity in five different forest types in Liangshui National Natural Reserve, China, each with three 25 × 25 m tree quadrats, twelve 5 × 5 m wide shrub quadrats and twelve 1 × 1 m wide herbaceous quadrats. Censuses of each forest type were conducted in 2016. New information The five main forest types presented differences in structure, diversity and species richness.


Introduction
The Korean pine forest of Liangshui National Natural Reserve is the most important primitive broad-leaved Korean pine forest in China and it is also one of the modern Korean pine distribution centres (Liu 2015, Zhang et al. 2000. The primitive broad-leaved Korean pine forest area is less than 40000 hm in China (Liu et al. 2014), while there are 4100 hm in Liangshui National Natural Reserve, accounting for 11% of the country (Liu et al. 2014). Liangshui National Natural Reserve is rich in biodiversity, preserves several species of the Tertiary plant communities and has an irreplaceable role in maintaining global diversity (Chen et al. 2012, Liu et al. 1993, Ma et al. 2007, Wang 1981, Rong et al. 2009). Korean pine forest has existed on earth for at least 30 million years, but the existing broad-leaved Korean pine forests of the Reserve formed about 3000 years ago. The Korean pine forest in this area is young, the age of the oldest individual is no more than 500 years, with a 1.5 m breast diameter. The tree height here is 15-40 m and seeds produced per plant are about 30 kg (Liu 2015). Although the Liangshui National Nature Reserve is very important, research for the different forests is not comprehensive and the data of plant diversity are still insufficient. In this research, the plant diversity of five different forest types in this area were studied, which provided the basic data for the study of biodiversity in this area.

Project description Title: Construction of Plant checklist Database in Heilongjiang Province
Personnel: Wang Hongfeng Study area description: Liangshui National Natural Reserve is located in the southeastern of the Xiaoxing'anling Mountains in Heilongjiang Province, China (47°7'39"-47°14'22" N, 128°48'30"-128°55'50" E). It is made up of hills, the terrain is high in south and low in north. The average elevation is about 400 m, the highest elevation is 707.3 m, the lowest is 280 m, mountain slope is generally 10-15 degrees (The Compilation Group Physical Geography of China 1986). This area belongs to the temperate continental monsoon climate. The extreme minimum temperature is -43.9 °C and the extreme maximum temperature is 38.7 °C. The annual average temperature is about -0.3 °C, positive temperature accumulated is 2200-2600°C. The average annual precipitation is 676 mm, June-August precipitation accounted for more than 60% of annual precipitation. The relative humidity in Liangshui is about 78%. The average annual evaporation is 805 mm, the total sunshine hours are 1848h, frost-free period is 100-120 days, the annual snow period is 130-150 days, frozen soil depth is about 2 m (Liu et al. 2014, Su et al. 2006). The forest types in this region mainly include five types of forest, namely Ulmus davidiana var. Step description: The dataset presented here was collected over a period of one year.   Table 3.

Geographic coverage
The number of species in each family in Liangshui National Natural Reserve.
The number of individuals in each family of tree in Liangshui National Natural Reserve.     Table 9.
The number of individuals in each species of herb in Liangshui National Natural Reserve.