Materials and Methods

4.2.1 Site Description

Beijing, the capital of China, is one of the oldest and fastest developing capital cities in the world. It has a population of 16.33 million and a built-up area of 873 km2 (Beijing Statistics Yearbook 2007). This study was conducted in the Beijing Teaching Botanical Garden, which covers an area of 11.65 x 104 m2 and is in the Chongwen District in the center of Beijing. Beijing, situated in a warm temperate zone, has a typical continental monsoon climate. Mean annual precipi­tation is about 585.8 mm with more than 70 % of the annual total occurring between July and August. Mean annual temperature is about 11.8 °C, varying between 11 and 12 °C.

Year

Tree number

DBH (cm)

Height (m)

Sapwood area (cm2)

LAI

Orientation of sensor

Number of sensors

2008

No. 1

17

5.9

163.56

2.07

South, north

2TDP30

No. 2

16.2

5.7

147.52

2.36

South, north

2TDP30

No. 3

18.7

5.8

200.60

2.82

South, north

2TDP30

2009

No. 1

17.1

5.9

165.63

1.79

South, north

2TDP30

No. 2

17.55

5.7

175.10

2.08

South, north

2TDP30

No. 3

20.3

5.8

239.17

2.23

South, north

2TDP30

LAI, leaf area index

4.2.2 Estimation of Sapwood Cross-Sectional Area,