1. Name: Lasa Plateau Ecological Research Station, The Chinese Academy of Sciences

2. Physical conditions :

Location：Dagze county, Lhasa, Tibet (21 km east to Lhasa city)

Latitude：29°40'40'N Longitude: 91°20'37'E　　　　 Altitude：3688 m

2.1 Vegetation 

The vegetation in Lhasa station is categorized as alpine shrub-grassland dominated by Sophora moorcroftiana and Aristida triseta. Other species, such as Ceratostigma minus, Orinus thoroldi, Pennisetum flaccidum, Poe spp., Oxytropis sericopetala, Stellera chamaejasme and Korbresia spp., are also commonly found in the community. Aspen and willow dominate the forest plantation. Crops in farmland are cool-like ones such as wheat, Tibet barley, oilseed rape, pea, horsebean, potato and various vegetables. The vegetable varieties cultivated in greenhouse are fairly abundant.

2.2 Soil

The soil in the station is brown soil developed from inundated materials in the valley. The physic-chemical prosperities are: pH 7-8.5, 1.5~2.5 % of organic matters, 0.015% of total nitrogen, 8.5, 48.0 and 107.5 mg respectively of fast effective N, P, K in per 100g soil.

2.3 Climatic conditions

The topography of Lhasa station is generally an open valley but with narrow at eastern and western sides. It is easy became a “cool lake” in winter because of cold airflow assemblage, to be “hot pool” in summer because of slow heat dissipation. The station is of temperate continental climate with annual mean temperature of 7.7℃, extreme maximum and minimum 27.4℃and -11.8℃ respectively. Daily variation and annual variation are 14.9℃ and 17.8℃. accumulated temperature of 30℃, 35℃ and 310℃ is 2978.3℃, 2743.2℃ and 2227.5℃ respectively. The annual relative humidity is 9％，with maximum of 65％ in September and minimum of 39％ in February. Annual precipitation is 425.4 mm，mainly concentrating during June to September, accounting for 94％.Solar radiation is abundant. Annual gross energy is 7700Mj.m-2, with Photosynthetically active radiation accounting for 43％. 1 joule of PAR is equivalent to 4.44 mmol light photons. Annual sunlight duration reaches 3000 hours, 68％ of the total. Mean ground temperature is 5℃ more than that of air temperature. Soil temperature in 5cm, 10cm, 15~20cm, 40cm, 160cm and 320cm are 11.4℃, 1.5℃, 12.0℃, 11.3℃, 11.5℃ and 10.9℃ respectively. Annual air pressure is 650.3 mbar，with maximum 653 mbar in September to October, minimum 645 mbar in February. Average wind speed is 3.1m.s-1 through the year.

3. Objectives

3.1 structure and function of main ecosystems and its response to environmental change Ecosystems mainly agricultural land will be chose to monitor long-term dynamics of ecological and environmental factors. Emphasis will put on energy (radiation and energy) and mass (main greenhouse gases and vapor) flow and cycling in the special environment of Tibet Plateau and their mechanisms.

The main research areas are to:

3.2 Optimal modes of sustainable agro-pastoral development Under the guidance of ecological principles, a series of key techniques for plantation, animal husbandry in agricultural area and agriculture-livestock combination will be research and demonstrate in the Lhasa River Valley. Suggestion of sustainable agro-pastoral development will be proposed for local government. The main objectives are to provide scientific baseline for agro-pastoral integration and industrialization in Tibet Autonomous Region.

The main research fields are to:

• propose key techniques for plantation, animal husbandry in agricultural area and agriculture and pasture combination
• establish sustainable modes of agricultural and pastoral development l explore sustainable approach to ecosystem management

4. Main Tasks

• long-term monitoring of climate, water, vegetation and atmosphere
• researching net primary production of vegetation, characteristics of biogeochemical cycling of carbon and nitrogen, sink/source relation, and their response to global change.
•  R and D of agriculture and livestock sustainable development l providing support base for Plateau ecology research and corporation
•  training personnel for Plateau ecology research

5. Database

5.1 Main ecological and environmental factors Lhasa station has been monitoring ecological and environmental factors such as climate, soil temperature, soil moisture, water table, biomass and net primary production. 200,000 records of climate, 3000 of water table, 5000 of soil moisture and nutrient and 100,000 of species introduction were collected since the establishment of the station.

5.2 Project database

A. Soil respiration database

(1). CO2 emission database (measured by CI-301PS infrared method) from May 1998 to September 1999，whole day measurement in winter wheat, barley cropland and non-crop filed

(2). Greenhouse gas (CO2, CH4, N2O) emission（by Closed chamber and chromatography） Lhasa station: winter wheat ecosystem: September 1999-August 2001 Bange alpine steppe ecosystem: September 1999-August 2001 Dangxiong alpine meadow ecosystem: June 2002 till now.

(3). Soil temperature (0cm, 5cm, 10cm, 15cm, 20cm), measured at the same time with soil greenhouse gas emission measurement.

(4). Soil moisture (0cm, 5cm, 10cm, 15cm, 20cm), measured at the same time with soil greenhouse gas emission measurement.

(5). Dynamics of biomass and net primary production in different organs, measured at the same time with soil greenhouse gas emission measurement.

(6). Phenology of crop and alpine dominant species

(7). LAI dynamics of main crops

(8). Physic-chemical prosperities of soil in research site

(9). Field management

(10).Soil N, P, K and organic matters

(11). Plant nutrient elements N, P, K and organic carbon

(12). Measuring diary

(13). Temperature and pressure in the measuring date.

B. Solar energy and photosynthesis

(1). Spectra of solar radiation

(2). Solar energy budget

(3). Photosynthesis of winter wheat (daily variation and seasonal change of different phenology) (4). Photosynthesis of aspen

(5). Photosynthesis of C3 and C4 crops and vegetable in CO2 elevation (2000-2002)

C. climate data base（since 1994）

(1). Climatic factors

(2). Auto-climate data of agriculture

(3). Radiation, soil temperature, and moisture automatic record data of Noka system presented by Hokkaido University (1997, 1999~2000)

(4). Water table

D. Baseline of Lhasa eco-station and surroundings

(1). Soil types and physic-chemical prosperities

(2). Water resource

(3). Tree variety data

(4). Cropping system

(5). Livestock status

E. Database of fodder variety introduction

(1). Fodder variety file

(2). Fodder variety of growth performance

(3). Phenology of fodder

(4). Fodder biomass and production data

F. Database of crop variety introduction

(1). Phonology

(2). Filed management

(3). Yield measurement

(4). Fertilizer application

6. Personnel

6.1 Research Group

6.2 Contact address In Beijing:

Dr. SHI Peili Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences (IGSNRR, CAS) P. O. Box 9717, 3 Datun Road, Chaoyang District,

Beijing 100101 P. R. China

Email: shipl@igsnrr.ac.cn

Tel: +86 10 64856520 Fax: +86 10 64854230

In Tibet: Dr. SHI Peili

Lhasa Plateau Ecosystem Experimental Station Chinese Academy of Sciences Dagze County, Lhasa 850100, Tibet Autonomous Region P. R. China

Email: shipl@igsnrr.ac.cn, peilishi@sina.com

Tel (fax): +86 891 6142216

6. The research achievements in the past 5 years

Since foundation of the Lhasa Plateau Ecological Research Station, we undertook more than 20 items of projects from National Key Project for Basic Research on Tibetan Plateau, China Natural Science Foundation, Chinese Academy of Sciences, Scientific Committee of Tibet Autonomous Region, and Logistic Department of Tibet Army.

The main achievements are as follows.

1) Basic Research

① Solar radiation and energy balance in agricultural ecosystem in Tibet Plateau Tibet plateau is characterized by high elevation and intense solar radiation. Since the foundation of Lhasa Agro-ecological experimental Station, solar radiation and its transformation in farmland ecosystem has been listed as the emphasis for study. Radiation input, energy interception and utilization in the canopy of farmland were studied. We measured spectra of solar radiation and analyzed the temporal and spatial distribution of different spectra. Photosynthetically active radiation (PAR) coefficient, i.e. ratio of PAR in gross solar radiation, was calculated through measured data. Results indicate that PAR coefficient is lower although total solar radiation is much higher than lowland of other part of China. The climatic model of PAR and conversion coefficient between energy of PAR and light photon were proposed in Tibet Plateau. It is important for calculating and modelling of productive potential, photosynthesis and mechanisms of high production. We also analyzed the characteristics of energy budget of solar radiation through measuring gross radiation, reflex, long-wave radiation and atmospheric converse radiation. The radiation budget is linearly correlated with gross solar radiation. Therefore we can calculate energy budget from solar radiation.

② Photosynthesis and its response to CO2 enrichment The Tibet Plateau is characterized by high elevation, lower atmospheric pressure. The density of carbon dioxide in the air is only two thirds of lowland in North China Plain. So the characteristic of photosynthesis in the plateau is quite different from lowland. Especially the photosynthesis of plant is sensitive to CO2 elevation and global warming. In 1995 and 1996, we measured photosynthesis of winter wheat flag leave by CID 301 portable photosynthesis system. We found that initial light utilization efficiency in the plateau is lower than that of lowland. In 2001, Lhasa ecological station, in collaboration with Hokkaido University, Japan implemented a project on the response of winter wheat photosynthesis to CO2 enrichment by method of open top chamber. The result showed that apparent quantum yields of photosynthesis are 0.04870 ± 0.003 and 0.04796 ± 0.0024 mmol CO2 /mmol photons in 25°C and 30°C. Apparent quantum yield is negatively correlative with air temperature. In comparison with the lowland area in North China Plain, the quantum yield, varying from 0.043 to 0.0570, is 76~87% of those in lowland (0.050~0.075). CO2 enrichment can apparently increase the light utilization efficiency, quantum yield increase 16.8 ~ 26.2 % in contrast with the controls. ③ Solar energy transmission and mass production In 1994，Bowen ratio microclimate method and eddy covariance was used to measure CO2 flux, transpiration, apparent and potential heat, net solar radiation and soil heat flux in winter wheat ecosystem in Lhasa. The result indicates that canopy net photosynthesis rate is linearly correlative to radiation budget, and is higher than that of lowland in North China Plain.

④ Crop production modelling We established models to simulate LAI dynamics, light interception and dry matter accumulation of winter wheat in Lhasa. Through modelling production process of winter wheat, we analyzed that the main cause of high yield is longer growing period due to cool climate. 15 t. hm-2 is the maximum production of winter wheat. We also simulated the winter wheat production under the CO2 doubling, and 3 °C temperatures increase. The result indicated that in the future climate change scenario, the production will increase but the growing period will be reduced. There is little production increase in contrast the lowland in the same climate change scenario because reduction of growing season. This will counteract the production increase effect.

⑤ Greenhouse gas release and ecosystem carbon budget Soil respiration of different land use, i.e. winter wheat farmland, barley farmland and control naked land, was measured by method of infrared gas exchange. It indicated that the soil respiration is positively correlative to soil temperature of 5 cm depth. 5 cm soil temperature can be used to evaluate carbon flux. We estimated that the root respiration accounts 34~44 per cent of soil respiration. Soil respiration also was measured in Lhasa winter wheat ecosystem and Bange steppe ecosystem by closed chamber. The annual emission of CO2, N2O and CH4 from soil are 20.30 t .hm-2, 0.98 kg.hm-2 and -2.15 kg.hm-2, in Lhasa winter wheat cropland and 2.66 t.hm-2, 0.23 kg.hm-2 and -2.11 kg.hm-2 in Bange steppe.

2) R & D projects

In this field, Lhasa ecological station carried out projects from Ministry of Agriculture, Tibetan Committee of Science and Technology, “Western Light” of personnel training, and Agricultural Development Office of Chinese Academy of Sciences. In addition, we also trained 400 persons for Tibetan Army and Tibet Agriculture and Livestock School.

The main achievements are as follows:

①　　 Demonstration and extension of crop varieties We introduced 135 varieties of crop since establishment of Lhasa Ecological Station. More than 10 varieties of high yield, high quality were selected and demonstrated in the station and in Tibet. Among others, winter wheat Bussyd, spring wheat 602, Northeast Agriculture maize series, oilseed rape series have prominent performance in the valleys of the Yalungzangbo River, Lhasa River and Nianchu River. Especially Bussyd winter wheat and 602 spring wheat was extended more than 15000 hm2. The Northeast-Agriculture sweet maize is also very popular in the Lhasa River Valley.

②　　 species screening of forage and artificial grassland construction 145 species or varieties of forage were introduced into experimental site in Lhasa station. More than 10 species, such as alfalfa、Vicina sp、sainfoin、Festuca arandinacea、Tall Festuca、Lolium perenne, 牧冰草、新麦草、青海老芒麦、Trifolium pretense et.al, These species was extended to North Tibet for demonstration and experiment. In the Lhasa River valley, branchy maize and Rumex are good species for fodder production. Their yield can reach 12000 kg.mu-1.

③　　 Vegetable cultivation in greenhouse Non-soil substrate vegetation in greenhouse has been successful in recent 3 years. From 2000 on, we constructed 500 m2 of plastic greenhouse and 340 m2 of glass greenhouse to research and demonstrate vegetable cultivation techniques. A series of vegetable such as cucumber, tomato, chili, eggplant, beans are cultivated. The production of cucumber and tomato can reach 9620 kg and 1280 kg per mu. Non soil substrate cultivation has he advantage of water and fertilizer saving and resistant to diseases and pests. This project was disseminated and demonstrated in Lhasa suburb and production base of the Logistics departments of the Tibet Army. 8. Introduction to undergoing projects