XIA Hexin

(Hunan Academy of Forestry, Changsha 410004, China)

ThegrowingregularityofintroducedD01Poplar

XIA Hexin

(Hunan Academy of Forestry, Changsha 410004, China)

D01 Poplar were introduced to the lower hills or branches of the Dongting Lake System in the middle reaches of the Changjiang River and the red soil hills on the south of the river from Arkansas of the United States. The results of introducing investigations showed that D01 Poplar trees reproduced easily and sprouted vigorously and their annual growing period was short and could be out annually. The annual growing amount of its asexual cutting wood assumed a“M” form. The trees grew rapidly in the early summer. Their leaves fell after the middle autumn and got into rest period and in this period they could be cut. In March of the next year the trees sprouted again, the annual growing period had 6 months. The difference in temperature of day and night, the annual mean temperature and sunshine and sunshine time were the main meteorologic factors affecting the growth of D01 Poplar.

D01 Poplar; introduction; growing regularity

D01 Poplar is indigenous to Arkansas of the United States.The pioneer research on D01 Poplar was made by the Energy Source Ministry of the United States in 1978, they obtained amazing production and found out many new ways of utilization. Later, through synthetic studies of Arkansas Test Institute of the Energy Source Ministry of the United States, the Bonnernrniu Power Management Office of the Forest Ministry of the United States, Arkansas University, Lolaho University and Washington College, the average fresh production of D01 Poplar reached 50 tons per acre a year. The supreme production reached 90 tons per acre a year. D01 Poplar coas harvested in the later two years, D01 Poplar can be used as fuel, feed and raw material of fibre[1-3]. Amazing economic effects were obtained.

In 1986, Xinyang Shen and professor Carter introduced D01 Poplar to the lower hills, beaches of Dongting Lake System in the middle reaches of Changjiang River. In 1989 D01 Poplar were introduced to the red soil hills in central Hunan. Through studies on the introduction, we found out a series of growing regularity of D01 Poplar and obtained many exciting achievements.

1 Natural conditions

The area planted with D01 Poplar can be divided into three regions in our studies. They are the lower hills of Yuanjiang, the beaches of Qianlianghu in Dongting Lake System, the red soil region in Changsha in central Hunan. Their geographical positions and conditions are presented in Tab.1.

The lower hills of Dongting Lake lies in the transitional place between the Xuefeng Mountain and the plain beside Dongting Lake. This land is Quaternary period type reticulated red soil (Yuanjiang).The beaches of Dongting Lake is an alluvial land of the rivers. The soil of this region is the violet aquoll and the violet sandy aquoll (Qianlianghu)[4-6].The soil of the hills in central Hunan is red soil which typical in southern part of China.

2 Methods

2.1 Introduction

Introducing in July 1984,Dr·Xinyang Shen from Arkansas Test Institute of US Energy Source Ministry brought branches of D01 Poplar to the Forest Seedling Nursery Yuanjiang County in Hunan. Vegetative propagation was then carried out. From 1985 to 1994, D01 Poplar were transplanted on the lower hills, the beaches of Dongting Lake and the hills of the central Hunan.

All the methods of introduction were asexual reproduction with the branches of D01 Poplar. The length of seedling branch was 20 cm, the two thirds of the seedling branch was inserted into the soil. One or two sprouts were left out of the ground. The distance between two lines or two branch in same line was 20cm.

Tab.1 TheconditionsoftheregionsplantedwithD01PoplarRegionLatitude(N°)Longitude(E°)Altitude(m)Meanannualtemperature(°C)Highesttempera-ture(°C)ThelowerhillsofDongtingLake(Yuanjiang)28°34'112°49'8816.939.4ThebeachesofDongtingLake(Qianlianghu)29°26'112°38'2616.638.2TheredsoilhillsincentralHunan(Changsha)28°26'113°10'3617.240.6Lowesttemper-ature(℃)Annualrainfall(mm)Relativehumidity(%)Annualsunshine-time(h)Sunshinepercen-tage(%)Frost-freeperiod(d)Soilthickness(cm)SoiltextureSoilpHvalue-11.21319.7811756.840276>50 claysoil4.5～-6.5-14.01179.4801196.538260>100sandysoil7.5～-8.5-11.31389.8801677.138275>40 claysoil5.0～-6.5

2.2 Evaluation of growth

The annual evaluation was conducted in December every year, which included measuring the height and diameter of trees and observing the characteristics of the branch growing during annual growing period. The growth evaluation and phenological observation were made per half month.

2.3 Analytic methods

The regularity of D01 Poplar in accordance with the growing curved line were analyzed using statistical analysis system and multiple regression and the following factors were concernedX1—mean annual temperature,X2—sunshine duration,X3—evaporation,X4—the difference of temperature between day and night,X5—annual rainfall and the growing regularity. At the same time, we analyzed the internal factors and external factors and set up an empirical mathematical model.

3 Results and discussions

3.1 Growth of D01 Poplar

According to the characteristics of D01 Poplar which can be harvested many times, we studied the growing regularity and the monthly production of the sprouting shoot of D01 Poplar and drew the monthly growing curved line with the growing regularity of D01 Poplar in six years.D01 Poplar sprouted after March 15. Their heights began to increase in April. Their flourishing growth period took place from the end of spring to summer. They ceased to grow on September 15.Their leaves began to fall on September 17.The rest period began on September 30.The flourishing growth period of D01 Poplar could be divided into two periods, which was from May 30 to June 15 and from July 15 to July 30.

3.2 Relationship between the growing regularity of D01 Poplar and climatic factors

The relationship between the height growth of the shoot sprouted and climatic factors could be known by analyzing the value of ︳bi ′︳in Tab.2 and Tab.3.The difference of temperature between day and night was the dominant factor affecting the height growth. The mean annual temperature and sunshine duration were closely related to the monthly height growth.

The difference of temperature between day and night, the mean annual temperature and sunshine duration were the main factors affecting the monthly height growth of D01 Poplar (Tab.2).

Data were analyzed by multiple regression analysis to examine the relationship between monthly shoot growth and various climatic factors. The multiple regression coefficient (R) was found significant. The results indicated that the pendent on the climatic factors. The monthly shoot growth demonstrated that the climate in the lower hills, the river beaches, especially the hilly land of Hunan Province agreed with the growth of D01 Poplar.

Tab.2 ThemultipleregressionanalysisofthemonthlyheightgrowthofD01PoplarandtheclimaticfactorsObservingpositionStandardregressioncoefficientMainregressiveparameterRX1X2X3X4X5Lowerhills-3.9304-1.67502.3950-44.82681.00011.0001**(2)(4)(3)(1)(5)Beaches3.9309-0.45250.2664-29.4502-0.03180.9999**(2)(3)(4)(1)(5)Hills6.5430-3.46112.587396.8296-0.01860.9998**(2)(3)(4)(1)(5) Notes:5%R=0.7700,1%R=0.8410.Numbersinside“<>”arepreferenceaccordingtothevalueof︳bi'︳.

The order of climatic factors affecting the monthly diameter growth was the difference temperature between day and night>mean annual temperature>sunshine duration>evaporation>annual rainfall (Tab.3).

Tab.3 ThemultipleregressionanalysisofthemonthlydiametergrowthofD01PoplarandclimaticfactorsObservingpositionStandardregressioncoefficientMainregressiveparameterRX1X2X3X4X5Lowerhills0.1079-0.01020.00300.77140.00110.9999**(2)(3)(4)(1)(5)Beaches0.0126-0.01220.01580.48690.00450.9999**(3)(4)(2)(1)(5)Hills0.0712-0.04110.00281.6170-0.0020.9993**(2)(3)(4)(1)(5) Notes:5%R=0.7700,1%R=0.8410.Numbersinside“<>”arethepreferenceaccordingtothevalueof︳bi'︳.

Data were analyzed by multiple regression analysis to examine the relationship between monthly shoot growth and various climatic factors. The multiple regression coefficient (R) was found significant for all the regions. Moreover there was little difference among the levels of the coefficients of the lower hills, the beaches and the hilly land. The results demonstrated further that the climate these above area agreed with the growth of D01 Poplar.

4 Conclusions

The introduction of D01 Poplar to the lower hills, beaches and hills of Dongting Lake in China was successful. D01 Poplar could adapt itself to environments of these regions.

The flourishing growth period of height and diameter of D01 Poplar was between the end of spring and the beginning of summer. The difference of temperature between day and night, sunshine duration and mean annual temperature provided best condition in this period in the south of China. So the flourishing growth period was key to increase the biological production of D01 Poplar.

D01 Poplar was utilized as a fuel forest or conserving water and soil in its native place in the United States. They obtained amazing production and effect. Much remains to be learned about D01 Poplar.

[1] XIA Hexin. Culture and introduction of poplar D series in America[J].Hunan Forestry Science & Technology, 1993, 20(3):1-3.

[2] LAN Chuanliang. Preliminary studies on seedling growth and energy characters of Poplar clones introduced from USA[D]. Nanjing: Nanjing Forestry University, 2008.

[3] CHEN Anqiang. Study on growth law and characteristics of transpiration water consumption of excellent poplar clones [D]. Taian: Shandong Agriculture University, 2009.

[4] WU Lixun, TANG Yuxi, WU Min, et al. Introduction experiments of poplar in the Dongting Lake area [J]. Hunan Forestry Science & Technology, 2003, 30(3):12-15.

[5] QU Maosheng, GONG Yuzi, YANG Jun, et al. The poplar plantation and forest paper industry development in the Dongting Lake area [J]. Hunan Forestry Science & Technology, 2003, 30(4):49-50.

[6] XIAO Xingcui, WU Lixun, TANG Yuxi, et al. The compare experiments on 18 strains of Populus in lake area[J]. Hunan Forestry Science & Technology, 2008, 35(3):20-22.

(文字編校：張 珉)

2012 — 07 — 01

美國(guó)能源部、中國(guó)林業(yè)科學(xué)研究院資助項(xiàng)目(1990 — 91 — 92)。

D01楊樹(shù)從美國(guó)的阿肯色州引種到長(zhǎng)江中游洞庭湖流域的低山、湖濱地段以及長(zhǎng)江南面的紅壤丘陵地帶。對(duì)D01楊樹(shù)的引種調(diào)查研究表明：D01楊樹(shù)繁殖容易、萌芽力強(qiáng)、生長(zhǎng)周期短；無(wú)性扦插木的年生長(zhǎng)量變化呈 “M”形；D01楊樹(shù)在初夏生長(zhǎng)迅速，秋季中期后落葉并進(jìn)入休眠期，次年三月再次萌芽，其年生長(zhǎng)周期為6個(gè)月；晝夜溫差、年平均氣溫和日照時(shí)間是影響D01楊樹(shù)生長(zhǎng)的主要?dú)庀笠蜃印?/p>

D01楊樹(shù); 引種；生長(zhǎng)規(guī)律

S 792.11

A

1003 — 5710(2013)04 — 0011 — 03

引種D01楊樹(shù)的生長(zhǎng)規(guī)律研究

夏合新

(湖南省林業(yè)科學(xué)院，湖南 長(zhǎng)沙 410004)

10. 3969/j. issn. 1003 — 5710. 2013. 04. 003