Problems in Transplanting Large Trees to Cities and Recommendations

Youxi County Forest Resources Management Station of Fujian Province, Youxi 365100, China

Abstract This paper first elaborated the purpose of accelerating the greening process, improving the landscape effect, and improving the ecological environment for transplanting large trees to cities. Then, it introduced main problems: destroying the ecological environment of the producing area, damaging the entire ecosystem, increasing the cost of social greening, and seriously wasting forest resources. It analyzed the reasons for these problems, including the imperfect laws and regulations, blind and not scientific transplanting, and eagerness for quick success. Finally, it came up with recommendations including improving policies and regulations, reinforcing technical specifications, and first pseudo planting then field planting, and setting up the overall point of view.

Key words Urban greening, Large tree transplantation, Forest resources, Ecological environment

1 Introduction

In the process of promoting urbanization in China, urban construction has been advancing by leaps and bounds, and earth-shaking changes have taken place. However, in the process of urban construction, to accelerate the greening, beautify and create livable environment, urban areas compete for purchasing large trees from rural areas and suburban areas and transplant those large trees to urban areas. Such large trees generally refer to deciduous trees with diameter at breast height (DBH) larger than 15 cm or evergreen trees with height above 5 m. In the process of transplantation, the technology is not standard, the transplantation season is not suitable, and ecological environment is not suitable. As a result, the survival rate is generally low or the plant growth is slow. It fails to achieve the greening purpose, and also leads to huge ecological and economic losses.

2 Purposes of transplanting large trees to cities

2.1AcceleratingthegreeningprocessThe growth cycle of trees is generally long. It takes many decades for many trees to grow into large trees from saplings. In order to accelerate the greening process, many cities naturally consider transplanting large trees to urban areas. If the transplantation of large trees is scientific and the survival rate is high, it will get instant results and accelerate the greening process.

2.2ImprovingthelandscapeeffectLarge tree is an indispensable elemental material for the greening, beautification and coloring landscape design pursued by the current urban greening. From the spatial level of urban greening landscape, large trees are landscape space leaders of urban green land, expand the main points of urban landscape to high level, and also play an important role in expanding internal landscape of green land and improving external landscape.

2.3ImprovingecologicalenvironmentUrban construction is mainly occupied by hard landscape, the natural ecology is fragile, and the exhaust of automobiles and air conditioners is large, and the noise is large. All these seriously affect people’s quality of life. However, trees, especially large trees, have a strong transpiration and photosynthesis, thus they can effectively increase the humidity and oxygen content in the air, and rapidly improve the ecological environment.

3 Main problems in the transplantation of large trees to cities

3.1DestructionoftheecologicalenvironmentofthetreeproducingareasRelevant investigations and studies have shown that a large number of trees are excavated in the mountains, leading to serious soil erosion and destruction of the ecological environment. Therefore, transplanting large trees to cities is, in essence, a violation of the natural laws of the growth of large trees. It will lead to serious damage to the natural ecosystem, causing losses and ecological disasters such as soil erosion, mudslides, sandstorms, floods. The losses are much greater than the economic benefits of selling large trees, in other words, loss outweighs the gain.

3.2DamagetotheentireecosystemForest is the main part of terrestrial ecosystem, and it is a holistic ecosystem that maintains ecological security and safeguards human survival and development. Excavating a large number of large trees, especially ancient and well-known trees, to cities, not only damages the ecology and environment of the tree producing areas and surrounding areas, leading to poor growth and even death of other plant types, but also causes loss of ecological functions due to death of large trees during transplantation and loss from terrestrial ecosystems. Such practice of transplanting large trees to cities is like "robbing Peter to pay Paul". It not only destroys local ecological and natural landscape, but also damages the entire ecosystem. The losses it brings to human beings are irretrievable.

3.3IncreasingthecostofsocialgreeningLarge trees are generally several thousand yuan per tree. Famous trees are more expensive. In addition to transportation expenses, the cost is huge. The cost of maintenance after transplantation is also high. According to statistics of urban greening department about the expenses for transplanting large trees to cities, each tree needs 200-500 yuan/year. Especially in winter, those large trees vulnerable to cold weather, they need to wear "coat" and be covered with "quilt". These measures are expensive. Such problem is more prominent for different ecological regions, such as transplanting south trees to north areas, or transplanting north trees to south areas, the maintenance expenses for large tree transplantation are higher.

3.4SeriouswasteofforestresourcesThere goes a Chinese saying that frequent shifts make a tree dead but a person prosperous. For example, 7-8 years ago, to implement greening project of Ziyang Park, Youxi County of Fujian Province purchased eight 40 year-old large camphor trees, six of them were dead and two had poor growth. The survival rate of large trees transplanted to cities is lower than 30%, but the death rate is higher than 70%. Most trees seem to survive after several years of transplantation, but they die successively. In fact, this 30% survival rate is mainly for smaller trees (diameter at breast height less than 30 cm, tree height less than 7 m, and crown width less than 6 m). Large trees with higher DBH have almost no survival rate. Even they survive, a large portion of their ground parts is cut, only about 1/20 is left, so the ecological function brought play after transplantation is less than 5% of the original trees. Thus, large tree transplantation is a huge waste of forest resources.

4 Causes for problems of transplanting large trees to cities

4.1ImperfectlawsandregulationsIn response to the rapid and high-intensity of transplanting large trees to cities in recent years, the state and even the provinces and autonomous regions have basically not introduced perfect laws, regulations and policies, and there is still no technical standard for transplanting large trees to strengthen and manage this behavior. The forestry, environmental protection, industry and commerce, urban management and other departments do thins in their own way, leading to the failure of local governments to monitor the management of large trees, and the laissez-faire practices adopted by some departments in the interests of economic benefits have intensified the trees. These aggravate various problems of transplanting large and famous trees to cities.

4.2BlindandnotscientifictransplantationMost transplanted "large trees" have been cut or pruned, and their roots have been cut off. In other words, they have received major operation. Thus, the transplantation must be implemented in strict accordance with technical specifications. Technologies are the most important life support for large tree transplantation. It is necessary to implement scientific transplantation according to the weather, temperature, environment, and tree species, to increase the survival rate of transplanted trees. However, in practice, few people care about this technology. Several workers are randomly asked to excavate large trees. Heads and roots of large trees are cut off, earth on roots is not kept according to the size of trees and growth of lateral roots, as a result, only a bald tree is left. The spring is suitable for transplantation, but some places wait till summer to do so, such blind and not scientific transplantation leads to low survival rate.

4.3EagernessforquicksuccessDriven by the incorrect performance concept, policy makers are eager to obtain the greening effect during their term of office regardless of the actual situation, at all costs, all urban greening projects prefers to use "large trees". In fact, some "large trees" have been in recovery for decades after transplantation, and they cannot grow. The purpose of achieving "immediate effect" is only an illusion. If transplantation is implemented at the seedling stage, and proper care is provided like transplanting large trees, seedlings can grow into large trees and their growth is much better than transplanted large trees. Such practice can not only save greening cost, will not damage the vegetation of original land, but also increase trees for the entire forest ecosystem. It is a pity to be taken official workers as tools for improving political achievements.

5 Recommendations

5.1ImprovingpoliciesandregulationsChina should legislate to prohibit the transplanting of natural forest trees, and prohibit the transplantation of ancient and famous trees, trees belonging to wild plants under top-level state protection, trees of public welfare forest, and rare trees. In addition, it is necessary to determine standards for transplantation of other large trees, divide trees into different grades according to the DBH, crown width or tree height. Because large trees (DBH greater than 30 cm, tree height greater than 7 m, and crown width greater than 6 m) are difficult to survive when being transplanted, it is required to prohibit the transplantation of these trees. Instead, it is required to encourage transplantation of seedlings in policies. The relevant competent authorities should strengthen the management of forest trees, stop the chaotic excavation and severely crack down on all illegal activities that damage the ecological environment.

5.2ReinforcingtechnicalspecificationsIt is recommended to formulate national and local standards for the transplanting of different tree species, and strictly reinforce the technical specifications for large tree transplantation. (i) It is recommended to choose suitable transplantation season, and transplant trees not in summer or autumn. (ii) Big holes should be excavated for transplantation, use yellow soil to bury root system, to facilitate stretch and growth of root system. (iii) During transplantation, it is required to keep big enough earth, wrap up in a proper manner, to prevent falling and drying of soil. (iv) Branch cutting for large tree transplantation should be professional. It is required to wrap up the cut area of branches to reduce the water loss. (v) It is recommended to strengthen the management after transplantation, and do a good job in sun-proof, insect and pest prevention, and watering.

5.3FirstpseudoplantingthenfieldplantingNow, there is a kind of company that is engaged in transplanting large trees. They enclose land to plant trees. In other words, they first conduct pseudo planting, then sell trees to other places for field planting. After going through the pseudo planting, large trees will become more adapted to new ecological environment, so the survival rate will be higher. Companies specially engaged in enclosing land for planting large trees have professional personnel to provide technical guidance. This way is favorable for increasing the survival rate of transplanted large trees. All areas should establish their own nursery bases, plant trees in enclosed land, and provide pseudo planted trees for urban greening.

5.4SettinguptheoverallpointofviewFor urban greening, beautification, and protection of forest ecology, it is recommended to set up a global concept and overall point of view. It is required to stick to the basic state policy of conserving resources and protecting the environment, cultivate trees from the whole society, plant more trees, increase forest resources, and establish the forest ecological environment for a local area and place. Besides, it is required to get rid of the practice of "robbing Peter to pay Paul" and get rid of the wrong manner of building the local areas into forest cities through destroying the forest ecology of other places. Large tree transplantation is a wrong way of urban greening. It leads to very low survival rate and fails to reach the purpose of urban greening and beautification. In summary, large tree transplantation destroys ecology and wastes forest resources. It is required to get rid of the practice of large tree transplantation.