The growing environment of deciduous trees

Location: South Asia and Australia. It is distributed in central China, south China, southwest China and other provinces, and is also a native tree species in Yanling. Scope of application: Melia azedarach contains toosendanin, which has insecticidal effect. Medicinal roots, stems and leaves are used to prevent and treat ring rot and latent whip. In recent years, Beijing and Tianjin have frequently launched large-scale projects, and there are some deciduous trees in the nurseries around these two big cities because of their own urban greening needs. The number of deciduous trees around Beijing ranges from 5cm to 6cm, followed by Ginkgo biloba, Fraxinus mandshurica, Sophora japonica, Toona sinensis and Fraxinus ash, and the number ranges from hundreds of thousands to hundreds of thousands. Compared with Beijing, the storage and use of some salt-tolerant varieties such as Fraxinus mandshurica in Tianjin have increased significantly. As the largest nursery in Tianjin, Liuyuan nursery has 50,000 and 30,000 seedlings with 3-5 cm and 5-8 cm ash respectively. And the use specifications are mostly concentrated above 5 cm.

However, due to the relative scarcity of agricultural land, high land rent and high labor cost, the nurseries around Beijing and Tianjin can not meet the requirements of local greening projects, and engineering seedlings, especially large-scale engineering seedlings, mainly rely on transportation from Hebei, Shandong and Henan. Relying on the geographical advantages adjacent to Beijing and Tianjin, Hebei Province gradually increased production. Since 2007, a number of emerging Miao townships such as Dingzhou, Gu 'an, Baoding and Bazhou have emerged.

Huayuanfa is the most important seedling wholesale market in Beijing and a barometer of Beijing's seedling demand. Judging from the market demand in 2006, the demand specifications of ash, ginkgo, Sophora japonica and Fraxinus mandshurica are the largest, which are concentrated in 15 to18cm, 10 to 12cm and12 to/kloc respectively. According to the market circulation data in 2006, the total circulation was 250,000 plants, among which 6.5438+0.3 million plants such as Fraxinus chinensis, Ginkgo biloba, Sophora japonica, Fraxinus chinensis and Toona sinensis had DBH greater than 8 cm. In addition, many engineering companies in Beijing have large-scale "self-retained goods", but they generally don't use them.

Dingzhou, as the earliest Miao township with the largest production area in Hebei Province, has a production ratio of 7: 13, of which more than 95% of the trees are sold to the north of the Yellow River. Among the seven tree species surveyed, except Aesculus chinensis, the other six tree species have a large number of seedlings, including hundreds of thousands of plants, such as Cortex Fraxini, Sophora japonica, Fraxinus mandshurica, Lu 'an in the north, Toona sinensis, etc., with a total of hundreds of thousands of plants, although ginkgo biloba is rare. However, the overall specifications are small, and the specifications of 3 to 5 cm in these tree species reach more than 60%. The top three varieties with seedlings over 8 cm are Sophora japonica, Fatong and Toona sinensis. There are hundreds of thousands of deciduous trees in the local nursery, including Populus tomentosa, Sophora japonica and fast-growing poplar. Due to the need of ecological forest construction in Beijing, the sales of fast-growing poplars are on the rise. The seedlings of 4-6 cm trees in Shandong province can account for almost 70% of the total seedlings of trees in the province, which is basically 3-4 times that of 7-8 cm trees. Among them, the top three seedlings of 4-6 cm size are Fraxinus mandshurica, Cortex Fraxini and Sophora japonica respectively, and the top three seedlings of 7-8 cm size are occupied by Sophora japonica, Cortex Fraxini and Fraxinus mandshurica respectively. In the 20th century, the number of large-scale trees from roads, house renovation, demolition and other ways is decreasing, and nursery products are used more. However, due to the short industrial development period, the supply of trees over 8 cm is in short supply.

Judging from the sales situation in 2006, the sales of paulownia ash and ash are good, and they are basically out of stock above 10cm. After freezing in winter, the supply of 7-8 cm paulownia white wax and Beijing white wax is also in short supply, which may directly lead to the price increase of these two varieties of 6 cm products. Albizia Albizia, Koelreuteria paniculata and weeping willows are also deciduous trees in Shandong nurseries. However, the diseases and physiological drought of Albizzia julibrissin have some negative effects on its sales.

The development of trees in Jining area has a long history, and the planting structure of manufacturers is quite reasonable. Alsophila spinulosa, Sophora japonica, Fraxinus mandshurica and Toona sinensis are the varieties with a large number of local seedlings. Moreover, these four varieties are all in the range of 3 to 8 cm, and the seedlings of each file are similar, which are 6.5438+0.6 million, 6.5438+0.2 million, 50,000 and 30,000 respectively. In addition, the number of local Huangshan Lu 'an obviously exceeds that of northern Lu 'an.

In Jining, cut and transplanted trees are the best to sell, with high price and survival rate. Today, these products account for almost 20% of the total local trees, and they are still increasing. Because trees are the main direction of attack in the local area, there is no case of cutting seedlings in the local area.

According to the survey figures in Weifang area, the number of seedlings in this area is relatively large, whether it is 3-5 cm or 5-8 cm. Among the seven varieties investigated, the seedlings of each variety are more than several hundred thousand, and the gray seedlings are more than one million.

However, judging from the price in 2006, the smallest horse chestnut in the nursery is the best. The unit price of 3 cm can be sold to 28 yuan, and the unit price of 8 cm can even be sold to 900 yuan. The lowest price is ginkgo biloba, which basically does not exceed 1/20 of the price of aesculus chinensis of the same specification.

The largest seedling in Huimin County, Shandong Province is Fraxinus mandshurica, with 3-5 cm and 5-8 cm seedlings of about 600,000 and 200,000 respectively. It is understood that there are almost no seedlings in the local area, so it is difficult to find 1 2 cm gray seedlings, and afforestation in barren hills requires a large number of seedlings of this specification, so gray seedlings have formed a new market gap.

In addition, in view of the practice of over-planting in previous years, local manufacturers took action from the beginning to strictly control the planting density in the newly developed areas; For the past producing areas, thinning was carried out by means of sales, uprooting and logging. 40% of the county's production areas are within this adjustment range. Due to climatic and geographical reasons, the output of deciduous trees in northern Jiangsu is far less than that in other provinces, so only Rugao and Changzhou Xiaxi are selected for investigation.

Xiaxi market ranks among the top three best-selling seedling markets in China. Its significance as a circulation center is far greater than its production significance. Inferred from the sales data in 2006, exotic seedlings account for a large proportion of deciduous trees sold here. In 2006, the total number of deciduous trees sold was nearly one million, of which only ginkgo accounted for half, and others, such as paulownia, Sophora japonica and Toona sinensis, were similar, and the sales volume of a single variety was 6.5438 million. Moreover, it is obvious that the specification of 5 to 8 cm is the main sales segment, which is almost close to 70% of the total sales.

Among the investigated tree species, Rugao basically only produces Toona sinensis, Sophora japonica and Ginkgo biloba in batches, and the amount of Ginkgo biloba in the nursery ranks first, with a total of less than 400,000 plants. Deciduous trees 10 cm above, 3-4 cm is the best to sell. Needless to say, the former is a new market brought by rural green network construction. In addition, Pu Shu, a native variety with good leaf color in spring and summer, was well received after being sold to Shandong and other places in 2007 and became one of the best-selling varieties in the local area. Northwest China has special natural conditions, such as Xinjiang, Ningxia, Gansu and other provinces, and most of them transport the required seedlings from zhouzhi county, Shaanxi. But now these places have begun to emerge and are basically self-sufficient. Take Ningxia as an example. According to Shen Xiaodong, most of the green seedlings used locally are 5-6 cm in size, and the price per plant basically does not exceed 15 yuan. Yongning, Pingluo, Tao Le, Helan, Yinchuan, He Lin, Inner Mongolia and other emerging Miao townships can provide Ningxia with 30,000 plants of Fraxinus mandshurica, Ailanthus altissima, Sophora japonica and Populus Xinjiang with a size of 5-6 cm each year, 654.38+00,000, 20,000 and 30,000 respectively. If it is not enough, we will transfer the goods from Shaanxi and Henan.

When it comes to the northwest, we must talk about Xi 'an and its nearby zhouzhi county, which is the largest nursery stock producing area in the northwest. Fraxinus mandshurica and Toona sinensis are planted here in a relatively small amount. The dominant tree species here are Sophora japonica, Ginkgo biloba, Cortex Fraxini, Luan tree and Aesculus chinensis, each of which has hundreds of thousands of seedlings, and the price of Aesculus chinensis is much higher than other trees of the same specification. It is worth mentioning that since the 20th century, the number of seedlings in Zhouzhi has gone from bad to worse, and the number of trees below 3 cm in the nursery is obviously less than 3-5 cm. In particular, weeping willows, one of the main local tree species, have much less storage, and the specifications of 2 to 5 cm are basically broken. Henan Province, as a big seedling province in the Central Plains, started seedling planting earlier, forming many well-known seedling towns. From the investigation, it is found that there are more than 200,000 aesculus plants planted in Henan Province, the specifications are concentrated in 3-5 cm specifications, and the unit price is about 20- 100 yuan. The price of large specifications is higher, but the output is not large. The planting amount of paulownia and ginkgo biloba is scattered in Henan. The situation of Sophora japonica is not optimistic either. Its size is 3 to 5 cm, and most growers have adopted the method of transplanting seedlings to other varieties. 5-8 cm Sophora japonica is also relatively large, and the price is between 15-70 yuan. In addition, the planting amount of Toona sinensis in the province is gradually decreasing.

As an important Miao township in this province, Huangchuan and Yanling have large seedling planting areas, exceeding 200,000 mu and 400,000 mu respectively. The storage and sale of deciduous trees should not be underestimated, but the planting density of trees in the two places is too high, so the price of some varieties of trees is lower than that of products with the same specifications in other regions.

Moreover, it is not difficult to see from the data provided by the two places that with the end of seedling sales in 2006, the number of products with 6-8 cm specifications in the two places decreased obviously, and the product specification structure changed greatly, which is obviously the "sequela" of the blind expansion of manufacturers in the previous two years.

There is almost no large-scale production of aesculus chinensis and Toona sinensis in Huangchuan area, and the varieties with large seedlings are mainly cortex fraxini and Fraxinus mandshurica, followed by Sophora japonica, Chongyang wood and Ginkgo biloba. The main competitive advantage here is that many local people are doing projects outside, and a large number of seedling brokers are running around, but problems such as outdated varieties and planting patterns have reduced the income of local producers.

The varieties with a large number of seedlings in Yanling are Sophora japonica, Fraxinus ash, Cortex Fraxini and Toona sinensis. Similar to Huangchuan, Yanling seedling producers also have problems. However, it is gratifying that the seedling associations in both places are actively looking for countermeasures for this.