Investigation and Analysis of Grassland Plant Germplasm in Zhalantun City of Eastern Inner Mongolia

Yang Mei ,Ji Guo-xu ,Gao Zhi-qiang ,Xu Wen ,Dong Lin-ling ,Wu Qing-ying ,and Cui Guo-wen*

1 College of Animal Sciences and Technology,Northeast Agricultural University,Harbin 150030,China

2 Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China

Abstract:The plant germplasm resources of Zhalantun grassland in the eastern Inner Mongolia were investigated in 2015.The order of plant biomass production in all the types of grassland decreased compared to 1985 as the followings: mountain meadow(76.72%)＞temperate meadow steppe (66.53%)＞lowland meadow (55.03%)＞temperate typical steppe (26.37%).There were 243 plant species belonging to 166 genera and 47 families in Zhalantun grassland,including 163 forage species,78 medicinal species and 82 ornamental plant species attributable to 103 genera of 33 families,65 genera of 29 families and 63 genera of 29 families,respectively.In addition,38 species of edible plants,29 species of toxic and harmful plants and five rare protected plants were found in this area.

Key words:grassland,investigation,plant composition,germplasm resource,utility value

Introduction

As an important terrestrial ecosystem in the world,grassland accounts for about 30% of the total land area(Zhang,2016).China is the second largest grassland plant resource country in the world after Australia(Yanet al.,2005).The grassland area is nearly four million square kilometers,accounting for 12.4% of the total grassland area in the world.Grassland ecosystem is the largest inland ecosystem in China,with an area of about 2.5 times that of forest and 3.2 times that of farmland (Su,1994).China's grassland is widely distributed and has a large geographical span.The natural and climatic conditions such as temperature,precipitation,soil and altitude are complex and diverse,thus forming a variety of types of grassland,which can be roughly divided into four ecological function areas:arid and semi-arid grassland in northern China,alpine grassland in Qinghai-Tibet,humid and semi-humid grassland in northeast and north China and grassland in southern China.China's grassland is mainly distributed in Tibet,Inner Mongolia,Xinjiang,Qinghai,Sichuan and Gansu provinces and autonomous regions,the grassland area accounts for about 75.1% of the total grassland area (Shenet al.,2016).

There are abundant plant resources in China.Some plants are irreplaceable forage resources for the development of animal husbandry.Some plants can be used as industrial raw materials such as energy,medicine and food,and some plants can be used as excellent genetic resources for crop breeding (Fuet al.,2018).Because grassland has important economic values,human beings have been using grassland resources for a long time.With the rapid development of population growth and animal husbandry,the use of grassland by human beings has already exceeded its normal load.In China,in order to solve the problem of food shortage caused by rapid population growth,reclamation of grassland has become the main way to solve this problem for a long time after the founding of the People's Republic of China (Fanet al.,2002).Up to now,the cultivated grassland area in China is 1.93×107hm2,accounting for 4.8% of the original grassland area,and the cultivated land area from grassland accounts for 18.2% of the national cultivated land area (Liuet al.,2009).

In the 1980s,the national grassland plant resource survey has been difficult to meet the national and government deployment of the sustainable development of grassland resources,so the plant resource survey is particularly important (Lvet al.,2016).With the decrease of grassland area and the aggravation of grassland's "three modernizations",the status quo of grassland plant resources can inevitably change greatly compared with that in the first national census.Although the second grassland survey was carried out in China in the early 21st century,it mainly focused on grassland area and grassland properties,rather than the germplasm plants.Therefore,the information on the species,distribution and reserves of grassland plant resources in each region needs to be updated urgently.It is important to comprehensively grasp the current status of grassland and grassland plant resources in each region for the scientific and rational conservation and utilization of grassland ecosystems.In this paper,based on the survey data in 2015 and the results of the first national grassland census,grasping the 30-year dynamics of the grassland in Zhalantun City and understanding the existing grassland base condition can help the fieldwork and scientific researches of grassland.

Materials and Methods

Survey area overview

Zhalantun City is backed by Greater Khingan Mountains and overlooks the Songnen Plain.Its geographical coordinates are 120°28'51''-123°17'30''E and 47°5'40''-48°36'34''N (Dong,2003).Climatically,it is a mid-temperate continental monsoon climate.High cumulative temperature effectiveness rainfall is mainly concentrated in summer.Grassland soil mainly includes dark brown soil,dark soil,dark meadow soil and swamp soil (Zhao,2011).

Sample selection and quadrat setting

In 2015,based on historical data and field investigation,a total of 30 sample sites covering all the local grassland types were set up.The distribution of sample sites was consistent with the distribution density of natural grassland in the region.The geographic information of sample sites is shown in Table 1.Each sample area was not less than 10 000 m2.Six 1 m × 1 m main quadrats were set in each sample site for detailed observation.The adjacent quadrats were required to be at least 30 m apart and as far as possible away from the boundary.Four secondary quadrats were set in each main quadrat within 2-5 m in four directions.

Table 1 Basic information of sample sites

Survey methods

Geographic information on sample sites,contained the latitude,longitude and altitude,were recorded by handheld locator.

The average height,coverage and Chinese name of each species of plant community in the main quadrat were recorded in detail,and the plants were mowed on the ground to weigh the fresh weight,and then dried in an oven at 65℃ to obtain the dry weight.The species names in each side sample were also recorded in detail.

All the plants appearing in the sample plot were photographed and specimens precessed according toFlora of China(Editorial Committee of Flora of China,2007),Flora of Inner Mongolia(Zhaoet al.,2016) andKey to Northeast Plants(Second Edition) (Fuet al.,1995) for identification and classification.

Data statistical analysis

Office 2013 and Origin 2018 were used to process and analyze data.

Results

Grassland area and utilization intensity change

In 2015,the plant germplasm resources of Zhalantun grassland in the east of Inner Mongolia were investigated.The order of grassland area and available grassland area in years decreased compared to 1985 as the followings: 1985 grassland area＞1999 grassland area=2003 grassland area＞2010 grassland area＞2015 grassland area,available grassland area in 1985=available grassland area in 1999=available grassland area in 2003＞available grassland area in 2010＞available grassland area in 2015.The grassland area decreased by 11.29%,11.29%,25.74% and 43.96%,compared to 1985,respectively.Available grassland area decreased by 13.63% and 34.49% in 2010 and 2015 compared to 1985 (Table 2).

Table 2 Changes in area and utilization intensity of natural grassland

Changes of community characteristics

The results showed that the lowest aboveground biomass of plants in 30 plots was temperate meadow steppe (plot number 19),which was 111.35 kg·hm-2in 2015 (Table 3).The highest was lowland meadow(plot number 29),which was 3 098.65 kg·hm-2.The order of plant biomass production in all the types of grassland decreased compared to 1985 as the followings: mountain meadow (76.72%)＞temperate meadow steppe (66.53%)＞lowland meadow (55.03%)＞temperate typical steppe (26.37%).

Due to different ways and intensities of grassland utilization,the height and coverage of plant communities in different grassland types in the region fluctuated widely.Among them,the minimum plant community height and minimum plant community coverage of all the kinds of grassland were lower than those in 1985,while the maximum height and coverage of plant communities increased and decreased differently compared with 1985.

Changes in community composition

According to the historical survey data,there were 554 species of plants in the natural grassland of the region in 1985,belonging to 272 genera,63 families.There were 243 species of plants belonging to 166 genera,47 families in all the investigated plots in 2015 (Table 4).

Table 3 Changes in characteristics of natural grassland communities in research area

Table 4 Species and proportion of grassland plant resources

Families

In 1985,according to the number of plant species contained in each family,the large families of grassland plants in the region included Compositae,Gramineae,Rosaceae and Ranunculaceae,which contained 217 species of 102 genera and four families,accounting for 6.35% of the total number of families,37.50% of the total number of genera and 39.17%of the total number of species.There were 219 species,105 genera and 14 families in the middlesized families,accounting for 22.22% of the total families,38.60% of the total genera and 39.53% of the total species.There were 102 species belonging to 49 genera and 29 families in small families,and 16 species belonging to 16 genera and 16 families in single families,accounting for 46.03% and 25.40%of the total families,18.01% and 5.88% of the total genera,and 18.41% and 2.89% of the total species,respectively (Fig.1).

There was a significant decline in plant richness in all the survey plots in 2015,leaving only one family of Compositae,with a total of 32 genera and 49 species.At that time,most of the local plants belonged to the middle and small families,each containing 90 species of 57 genera and six families and 84 species of 57 genera and 20 families,accounting for 12.77% and 42.55% of the total families,34.34% and 34.34% of the total genera,and 37.04% and 34.57% of the total species,respectively.There were 20 species of single family,single genus and single species,accounting for 42.55% of the total families,12.05% of the total genera and 8.23% of the total species (Fig.1).

Fig.1 Proportion of families

Genus

In 1985,the natural grassland plants in the region belonged to 273 genera,of which more than half belonged to single genus and single species,accounting for 57.72% of the total genera.There were 12 genera with more than five species of plants,accounting for 4.41% of the total genera,including 117 species of plants,accounting for 21.12% of the total species (Fig.2).There were 103 genera containing two to five species,including 280 species,accounting for 50.54% of the total species.

Fig.2 Proportion of genus

However,in 2015,the grassland plants in the region were mostly single genus and single species,accounting for 77.11% of the total genera and 52.67% of the total species,respectively.There were 34 genera with two to five species of plants,covering 84 species of 17 families.Only four genera with more than five species were Polygonum of Polygonaceae (six species),Potentilla of Rosaceae (eight species),Artemisia of Compositae (11 species) and Carex of Cyperaceae (six species).

Species

Although the plant species in the area decreased significantly compared to 1985,the families containing the most plants in the plant composition of natural grasslands all included Asteraceae,Gramineae and Rosaceae.

There was one family containing more than 30 plant species,two families containing 20 to 29 plant species,four families containing 10 to 19 plant species,20 families containing two to nine plant species,and 20 families containing only one plant species in 2015(Table 5).

Table 5 Number of species

Classification of plant germplasm resources

By reference toChinese Journal of Feeding Plants(Jia,1987),Pharmacopoeia of the People′s Republic of China(National Pharmacopoeia Commission,2018),the Germplasm Resources of Ornamental Plants in China(Zhang,2013),Identification and Health Care of 500 Chinese Wild Vegetables(Xionget al.,2019),Handbook of Oil Plants in China(Institute of Botany Chemistry,Chinese Academy of Sciences,Oil Composition,1973),Main Wild Fibrous Plants and Their Utilization in China(Liu,1960),ChineseAromatic Plants(Wang,2008a;Wang,2008b),Rare and Endangered Plants in China(Department of Wildlife Conservation and Nature Reserve Management of State Forestry Administration,Institute of Botany of Chinese Academy of Sciences,2013)andDirectory of Important Poisonous and Injurious Plants in China(Zhao,2015),554 species of natural grassland plant resources in 1985 and 243 species of natural grassland plant resources in 2015 were divided into seven categories: forage plant resources,medicinal plant resources,ornamental plant resources,edible plant resources,industrial plant resources,toxic and harmful plants,and rare and protected plant resources.

Forage plant resources

It can be seen from Table 4 that the number of forage plant resources in the five grades decreased to varying degrees.In 2015,there were 30 species of forage plants belonging to 24 genera and seven families,accounting for 18.29% of the total number of forage plants (Table 6),51 species,38 genera,19 families of good forage plants,accounting for 31.10% of the total forage plants (Table 7),64 species,47 genera and 20 families of medium forage plants,accounting for 39.02% of the total forage plants (Table 8),15 species,14 genera and seven families of low-grade forage plants,accounting for 9.76% of the total forage plants(Table 9),and there were two families,three genera and three species of inferior forage plants,accounting for 1.83% of the total number of forage plants (Table 10).Among them,the superior forage plants were mainly Gramineae and Leguminosae,and the good and below forage plants were mainly Gramineae and Compositae.

Table 6 List of top forage plants in research area

Table 7 List of good forage plants in research area

Table 8 List of medium forage plants in research area

Table 9 List of low forage plants in research area

Table 10 List of inferior forage plants in research area

Resources of medicinal plants

Medicinal plant resources are an important part of Chinese herbal medicine resources.With the continuous development of Chinese herbal medicine industry,more and more medicinal plants are reasonably developed and utilized,and the demand for medicinal plants is also increasing.According toPharmacopoeia of the People′s Republic of China(National Pharmacopoeia Commission,2018) andFlora and Pharmacology of Inner Mongolia(Zhu,2000b),the resources of grassland plants in 2015 were classified.Table 11 showed there were 78 species of medicinal plants belonging to 65 genera and 29 families.

Table 11 List of medicinal plants in research area

Ornamental plant resources

Ornamental plants are widely used in urban landscape,greening or family support because of their color,smell and shape characteristics,so as to play their important roles in beautifying and protecting the environment.Grassland plants are important sources of ornamental plants,many famous ornamental plants have been cultivated and domesticated by wild plants.Ornamental plants can be divided into flower,leaf and fruit three types according to different ornamental parts.Table 12 showed there were 82 species of ornamental grassland plants belonging to 63 genera,29 families in the sample plot in 2015.

Edible plant resources

Chinese people had always the habit of eating wild vegetables.After long-term life practice,there were hundreds of edible wild plants and 90 common species(Zhu,2000a).Statistics showed that there were 38 species of grassland plants with edible value in this area in 2015,including the most well-knownArtemisia integrifoliaandAllium tuberosum(Table 13).

Table 12 List of ornamental plants in research area

Table 13 List of edible plants in research area

Industrial plant resources

As an important raw material for food,chemical,pharmaceutical,textile and other industries,industrial plant resources play an irreplaceable role in the national economy.Industrial plants can be divided into oil plants,aromatic plants,fiber plants,tannin plants,spice plants and dye plants according to their main components.Statistical results showed there were 64 species of grassland wild plants with industrial values in 2015 (Table 14).

Table 14 List of industrial plants in research area

Toxic and harmful plants

Toxic and harmful plants refer to plants of endanger local ecosystems,livestock and human health,including invade uncontrollable species,containing toxins plants and plants that are affected by attachments such as velvet outside plants.By comparing the list of important poisonous and harmful plants in China(Zhao,2015),indigenous experts identified and classified for 243 natural grassland species.Table 15 showed there were 29 species of toxic and harmful plants,belonging to 25 genera and 13 families.Most of them could not be directly fed livestock or could be fed in large quantities after treatments.Among them,Ranunculaceae contained more toxic species.

Table 15 List of toxic and harmful plants in research area

Rare protected plant resources

By consulting theList of Rare and Endangered Plants in China Volume 1(National Environmental Protection Bureau,Institute of Botany,2013),Red List of Biodiversity in China-Higher Plant Volume(Ministry of Environmental Protection,2013),Rare and Endangered Plants in Inner Mongolia(Forestry of Inner Mongolia,1989) and other related works,it was clear that there were five rare and protected plants in the surveyed natural grassland plants in 2015,which wereGlycine soja,Paeonia lactiflora,Phedimus aizoon,Platycodon grandiflorusandLilium pumilum.

Discussion

Causes of natural grassland degradation

The Hulun Buir annual report showed that the area of natural grassland in Zhalantun City had been reduced by nearly half in the past 50 years,with the proportion of grassland area decreasing from a peak of 25.38% to 12.69% (Compilation Committee of Hulun Buir Yearbook,2020).Except for some nonbasic grasslands that were changed to industrial land due to regional economic development,most of the grasslands disappeared due to the reclamation of agricultural land.Some grasslands were legally reclaimed at the beginning of the founding of the country,to increase the farmland area to meet the people's demand for food (Wang,2006).While the rest were caused by excessive reclamation,which was related to the rapid increase in population (Zhanget al.,2014).According to statistics,the local population was second to Hailar,but only ranked 10th in terms of land area among all the cities and counties under Hulun Buir's jurisdiction.Moreover,there were many forest lands in the territory,and the suitable land for cultivation was even more difficult to meet the needs of the local population,so it was not surprising overcultivation occurred from time to time.Of course,the reduction of the national grassland area and the serious grassland situation was highly valued by the state,with the implementation of the ecological protection concept of "green water and green mountain is the silver mountain of gold" and "mountain,water,forest,lake and grass community of life".The phenomenon of local grassland reclamation had been stopped,and some of the over-cultivated grassland had been returned to grass.

The statistical results showed that most of the existing grasslands in Zhalantun City was of medium quality,while a few of them were of high quality but with low biomass and even poor quality.The reasons are,one side,most of the local natural grasslands are dominated byCarex spp.And most of them are medium forage plants,whose grade is low.For another,the actual stock of ruminants has increased rapidly in Zhalantun City in the past 50 years.All the existing grassland almost has been exceeding the reasonable livestock carrying capacity.The combination of these two factors has led to the overall low quality of grassland.

Analysis on current status of utilization of grassland plant resources

Grassland plant resources are the most widely distributed and abundant natural resources in the world,providing important production materials for human survival and development,providing the most basic forage resources for livestock development,being a gene pool for agricultural improvement,and being a direct bearer of grassland carbon sink,making important contributions to global ecosystem stability and climate maintenance.In this paper,the statistical classification of natural grassland plant resources in Zhalantun City showed that the local grassland plant resources were very rich in varieties,mainly for forage,medicinal,ornamental and industrial uses.And there are great development prospects due to most of the plant resources are unexploited.

Forage plant resources are the most abundant local plant resources.Although the overall forage grade of local grasslands is low,there are many excellent forage plant species,some of which have been cultivated with corresponding cultivars.But still most of the plant resources have not been given enough attention or well exploited.Currently,the policy of "grain to forage"is being vigorously implemented,and the screening of high-quality native plant resources is of great significance to improve the forage cultivation structure and even the management of degraded grasslands.

Grassland medicinal plant resources are an important part of China's traditional Chinese medicine,most of which are collected from natural grasslands.The "Compendium of Materia Medica" and "Sheng Nong's herbal classic" are important world-class pharmacological related works.Most medicinal plants are whole herb or roots,and the medicinal values of wild plants are higher than those of artificial grown species.The collection of medicinal plants is more destructive to natural grasslands.One could see the pits and bales of earth appeared due to the digging of the whole plant in Zhalantun City,because there were medicinal plants such asPlatycodon grandiflorus.Excessive excavation led to a sharp decline in the reserves of plants with high medicinal values and serious damage to grasslands (Huoet al.,2014).Therefore,reasonably protecting wild medicinal plant resources,protecting the ecological environment of natural grasslands,and safeguarding the economic interests of local farmers were important issues facing the realization of sustainable use of grassland plant resources (Liet al.,2015).

The degree of development and utilization of ornamental and industrial plant resources is lower than that of forage and medicinal plants,therefore,there is more room for development.Efficient using local high-quality plant resources and cultivating more marketable rural plant resources could help the local ecological needs and enhance the local economy,which was the best protection of plant resources,such as the construction of beautiful villages (Chenet al.,2015;Chen,2016).

Most food-loving and food-savvy Chinese people will not let go of any edible food.Most edible plants are discovered by the toiling masses,because these wild vegetables are often initially used by poor people to feed their hunger "food".As people's standard of living is improved,they are more concerned about being natural and healthy.Therefore,these natural edible plants are becoming more and more popular,and a series of books and works such as "the Complete Chinese Wild Vegetables Cookbook" and "Delicious Wild Vegetables Recipes" have been published.After the field survey,a total of 38 species of edible plants from 16 families and 30 genera were found in the natural grassland,including young elm tree seeds,Taraxacum mongolicumandArtemisia integrifoliawhich were familiar to the local people,and "leek flower" which was the most widely known plant in Inner Mongolia (Maet al.,2019).These foods not only enrich the local people's dinner tables,but also some plants create great economic values for the local people.

The comprehensive and systematic inventory conduction of natural grassland plant resources in Zhalantun City is of good practical significance for the recognition and rational use of local plant resources.Especially some toxic and harmful plants have good medicinal values or high feeding values at one time,which can cause harm to livestock at other times,unfortunately.Therefore,the scientific and rational uses of plant resources are very necessary.Moreover,some of the high-quality plant resources have declined due to overuse,and some plants are even in a mildly endangered state.Statistical results showed there were five kinds of rare and protected plant resources in the local area,some of which belonged to the natural distribution and low reserves of wild plant species and became rare and protected plants,such as fine leaf lilies.Some were caused by over-harvesting,such asPlatycodon grandiflorus.Therefore,scientific and reasonable use of grassland plant resources is an important way to achieve sustainable development and use of grassland.

Conclusions

In 2015,the total area and available area of natural grassland in Zhalantun City of Inner Mongolia were 212 900 and 183 100 hm2,respectively,which decreased by 43.96% and 34.49% compared with 1985.The types of grasslands were still lowland meadow,temperate meadow grassland,mountain meadow and temperate typical grassland.Compared with 1985,only the area of lowland meadows increased by 38.25%,while the area of the remaining three types grasslands decreased by 79.90%,47.20%and 47.47%,respectively.

Compare with 1985,the average aboveground plant biomass in 2015 decreased by 26.37%,76.72%,55.02% and 66.53% for lowland meadow,temperate meadow steppe,mountain meadow and temperate typical steppe,respectively.And the average minimum height of plant community decreased by 21.20%,68.80%,74.40% and 88.86%,respectively.The current grassland class was dominated by medium quality and medium yield.

The plant species in 2015 survey sample sites were 243 species in 166 genera of 47 families.Among them,there were 164 species of forage plant resources in 103 genera of 33 families,78 species of medicinal plant resources in 65 genera of 29 families,82 species of ornamental plant resources in 63 genera of 29 families,38 species of edible plant resources in 30 genera of 16 families,64 species of industrial plant resources in 56 genera of 33 families,29 species of toxic and harmful plants in 25 genera of 13 families and five species of rare protected plants.