biodiversity
Simply put, biodiversity refers to all biological resources in nature, such as plants, animals, microorganisms and their ecosystems, as well as chromosomes, genes and DNA, which are important cornerstones of life.
We humans are part of biodiversity ourselves. Biodiversity makes it possible for life to survive on the earth. Without biodiversity, it is difficult for you to survive on this planet. Even if you can survive, you can't like this gloomy, lifeless, bare and boring world. Without biodiversity, you can't feel the green brought by the forest, the blue brought by the ocean, the air you breathe, the food you eat and the water you drink.
Forest biodiversity refers to the collection of all living things and their living ecosystems. Therefore, biodiversity has three levels: genetic diversity, species diversity and ecosystem diversity.
So what is an ecosystem? Ecosystem is the environment in which different species live. An ecosystem can be big or small, as small as a drop of water, as big as a forest, a park, a city or even the whole earth. The forests or beaches where we camp, mangroves, swamps and coastal estuaries are all ecosystems.
Biodiversity supports the life system on the earth.
Biodiversity can help clean the air we breathe and the water we drink, provide us with food, provide us with raw materials for building houses, and bring us endless beauty in nature.
In fact, it is biodiversity that makes life on earth sustainable. By absorbing the greenhouse gas carbon dioxide and releasing oxygen, we can breathe the air we depend on. Only through the changes of soil, microorganism and weather can we get rid of the dirt in the water, can we drink clean water. It can be said that biodiversity provides the lungs, muscles, stomachs, intestines, kidneys and heartbeats that sustain life activities on earth.
However, unscientific and unsustainable human development activities have threatened the survival of many species and are threatening the magnificent and irreplaceable life support system that constitutes the earth.
You may ask, are some unknown species really that important? If the species in this world are reduced to cattle, sheep, chickens, pigs and enough animals in zoos, can't we live comfortably? Why should we pay attention to some unknown animals or a small plant that lives in a distant swamp? What does it matter to us that they are extinct? You may also ask, even if some species are extinct, aren't there a lot of species left? We have identified 6.5438+0.75 million species. According to scientists' estimation, there are at most 1.3 million or even 1 100 million species on the earth. So what are we worried about?
It is important that all species are interrelated and interdependent, just as we depend on plants and animals for food, herbivores feed on plants and carnivores feed on other animals. If a particular species loses its habitat or can no longer find its usual food, it will become extinct. Therefore, each species plays a vital role in the survival of the whole ecosystem. In fact, it also plays a key role in the global ecosystem of the earth. For example, agricultural ecosystems polluted by pesticides will threaten birds that feed on insects or fish, especially migratory birds. On the one hand, it will cause birds to bring pollutants to other ecosystems, on the other hand, it will force birds to find food and stay in other places, which will lead to changes in the seasonal migration law of birds. Another example is that birds pollinate many plants with bees, butterflies, moths and bats. If they are not pollinated, these plants will become extinct and disappear. It can be seen that if a species link is lost in the food web of the ecosystem, the whole network will begin to collapse. Repairing food webs is very difficult and sometimes even impossible. The extinction of enough species will shake the structure of life system on the whole earth. Finally, what we do to biodiversity will eventually hurt ourselves.
Forest is the most biodiversity-rich ecosystem.
The three global terrestrial ecosystems-farmland, forest and grassland-support the world economy and provide almost all raw materials except minerals for human beings. Except seafood, they provide almost all food for human beings. Among these three systems, forest is the most important type on the earth, occupying a particularly important position and being the distribution center of biodiversity in the world. Tropical forest is an important distribution center in forest biological system. The area of tropical forests in the world only accounts for 7% of the land area, but it concentrates more than 50% of species, more than 80% of insects and more than 90% of primates in the world. Among the 65438+75 million species described in the world, there are more than 65438+0 million species of insects and higher plants, most of which are distributed in tropical forests.
Guangdong Province is located in the southeast of Eurasia, bordering Nanling Mountains in the north and tropical oceans in the south. The Tropic of Cancer runs through the middle. It has three climates, namely, the northern tropical climate, the southern tropical climate and the central Asian tropical climate. With complex geological structure, special topography, numerous rivers and harbors and vast sea areas, it is the main stopping place, breeding place and wintering place for international migratory birds. Guangdong, with its ancient origin, various species, complex components and many endemic species, is one of the origin centers of Cathaysian flora. Guangdong is also a major forestry province with "seven mountains, one water and two fields". According to statistics, the province has forestry land 1083 1000 hectares, including 9.33 million hectares of forest land. The forest stock reached 350.9 million cubic meters, and the forest coverage rate was 57.3%. There are rich species of forest plants in the province, including 7055 species of vascular plants belonging to 280 families 1645 genera, accounting for 76.9%, 5 1.6% and 26% of the national total respectively, including more than 4000 species of woody plants, accounting for 80% of the national woody plants. There are 77 1 species of terrestrial wildlife, including mammals 1 10, birds 504, reptiles 1 12 and amphibians 45. Such rich wildlife resources not only maintain the ecological balance of the whole province, but also have great significance for the development of agriculture, forestry, horticulture, medical and health care, scientific research, popular science education and eco-tourism.
Why is biodiversity destroyed?
Today, the threat to biological species is the greatest ever. The essence of all these threats is caused by human's improper management of biological resources, which is often encouraged by misleading economic policies and imperfect systems. The natural extinction of species is a fact of life and a natural law. At present, it is estimated that at least one or two million species are survivors of billions of species that once lived. In the past, extinction was caused by natural processes, that is, natural extinction, but today, human activities are undoubtedly one of the most important reasons for accelerating species extinction. The destruction of biodiversity by human beings is mainly reflected in the following aspects:
The growing demand for food, energy and other natural resources.
Human ignorance and indifference to biodiversity
Short-sighted behavior regardless of long-term effects
Air, water and soil pollution
Lack of recognition of the economic benefits of biodiversity
Failure to prevent excessive use and proper management of resources
The increase of human migration, travel and international trade leads to the invasion of alien species.
Overkill and overfishing
Collect rare butterflies, birds, ancient trees, roots and other species as specimens or transplant them into garden trees, sculptures and bonsai.
Scientists believe that now is the biggest biodiversity crisis after the extinction of dinosaurs 6.5 million years ago. It is our unreasonable economic development, deforestation, uncontrolled sewage discharge and so on. This has greatly destroyed the natural habitat of species. For example, 45% of the forests on the earth were cut down, mostly in the past 100 years.
Historically, Guangdong is rich in forest resources, and its forest changes are closely related to population growth, economic, social and productivity development. In the pre-Qin period, the whole territory of Guangdong was covered by tropical and subtropical virgin forests, and even the Pearl River Delta and Hanjiang Delta, which were covered with trees, were vast, with cypresses, bamboos and other trees everywhere. During the Qin and Han dynasties, the population increased, agriculture and handicrafts developed to a certain extent, and the development and utilization of forests increased day by day. However, compared with the vast land, the population density is still very small, and the damage to forests is not obvious. During the Sui and Tang Dynasties, the social economy of the whole country got unprecedented development. Although Guangdong has further developed, it is still an economically underdeveloped area in the whole country, and most areas including the Pearl River Delta are still densely forested, which can be proved by the descriptions of miasma and elephants in many ancient books at that time. During the Yuan and Song Dynasties, Guangdong's economy began to develop at a high speed, the population increased greatly, and the utilization of forest resources was obviously accelerated, especially in the Pearl River Delta, Chaoshan Plain and coastal areas, which were basically severely damaged. According to records, there have been no elephants in the Pearl River Delta since the Song Dynasty. The Ming and Qing Dynasties were the heyday of Guangdong's development, with rapid population growth, rapid development of agriculture, handicrafts and commerce, insufficient cultivated land, dried up plains and massive deforestation and utilization of forest resources in mountainous areas. By the end of the Qing Dynasty, except for the dense forests in the mountainous areas of northern Guangdong, northeastern Guangdong and western Guangdong, most of the other areas had become cultivated land or wasteland. During the Republic of China, due to years of warlord melee and foreign aggression, the destruction of Guangdong forests was more intense. The forests in the Hanjiang River Basin are the most seriously damaged. Soil erosion is also the most serious, and Dongjiang, Xijiang and Beijiang river basins are mostly replaced by artificial Chinese fir forests, bamboo forests or masson pine forests. So far, natural broad-leaved forest is limited to a few areas.
It can be seen that the historical changes of Guangdong forests are closely related to the growth of population, the development of agricultural production, the plunder of the ruling class and the destruction of war. As the area of primitive natural forest decreases, the forest coverage decreases and the artificial ecosystem increases, the biodiversity decreases and the species of rare and endangered animals and plants increase, which directly or simply induces more and more frequent natural disasters. According to statistics, there are about 360 species of rare and endangered plants in Guangdong Province, belonging to 87 families and 209 genera, among which 8 species are listed in the first batch of national key protected wild plants (Grade I key protection) and 65 species are listed in the second-class key protection; There are 35 species of national first-class protected wild animals, and the second-class protected wild animals 15 1 species. Therefore, the task of forest biodiversity protection in Guangdong Province is still very arduous.
Establishing nature reserves is an important way to protect forest biodiversity.
The construction of nature reserves is the most effective measure to protect wild rare and endangered animal and plant resources and their habitats. The significance of establishing nature reserves lies in: protecting the natural background and making human beings more accurately understand the restrictive relationship between organisms; Protect reserve species and realize the sustainable utilization of biological species resources; Maintain a reasonable ecosystem structure and maintain ecosystem balance; Preserve the aesthetic value of nature; Nature reserves are also good places for scientific research and popular science education.
Nature reserve is an area with a certain spatial scope established to protect nature and its natural resources. Nature reserves are representative natural landscape areas, such as zonal natural forest vegetation, natural distribution areas of rare animals and plants, important natural scenic spots, water conservation areas, natural geological or fossil producing areas with special significance, and protected areas designated for scientific research, education, culture and entertainment.
As early as 1956, Guangdong Province took the lead in establishing the first nature reserve in China-Dinghushan National Nature Reserve. After 50 years of development, Guangdong has become the province with the largest number of nature reserves in China, and it is also the province with the best management system and staffing of national and provincial nature reserves. Up to now, Guangdong forestry system has established 237 nature reserves with forest ecosystem, wetland ecosystem, terrestrial wildlife and terrestrial wild plants as the main protection objects, with a total area of 1.07 1.500 hectares, including 5 national nature reserves with an area of 97,800 hectares. There are 42 provincial nature reserves, covering an area of 4410.2 million hectares; City and county nature reserves 190, covering an area of 532,500 hectares; In addition, the province has established 38,800 nature reserves with an area of 420,000 hectares. The total area of national, provincial, city and county nature reserves in the province is 1.07 1.500 hectares, accounting for 5.96% of the province's land area. A nature reserve system with national nature reserves as the core, provincial nature reserves as the network, city and county nature reserves and nature reserves as the channels has been initially formed, with complete protection types, reasonable layout, scientific management and remarkable ecological and social benefits. Most rare and endangered species and national key protected species have been well protected.
At present, there are still many problems in the construction of forest ecosystem nature reserves in Guangdong Province, such as the large number of protected areas, the small average area of a single protected area, the low proportion of the total area of protected areas to the national territory, and the unreasonable geographical distribution of protected areas. Some rare and endangered species, especially the plant species endemic to Guangdong, have not been protected, such as the pig blood wood endemic to western Guangdong, and some important ecosystem types have not been designated for protection, such as the karst forest ecosystem in limestone areas. Facing the construction forms of "green Guangdong" and "harmonious Guangdong", it is necessary to speed up the construction of nature reserves.
Fortunately, the 11th Five-Year Plan and the medium-and long-term development plan of nature reserves managed by Guangdong forestry system have been completed and will be implemented soon. By the end of the 11th Five-Year Plan, there will be 363 nature reserves managed by the forestry system in Guangdong Province, including 1 1, 62 provincial nature reserves and 290 county (city, district) nature reserves, with a total area of1426,500 hectares, accounting for 7% of the national land area. Initially establish a network system for resource supervision in nature reserves; Carry out the evaluation of the management effect of nature reserves focusing on national nature reserves and provincial nature reserves, and realize the dynamic management of nature reserves by classification and grading; Increase the construction of facilities and equipment for publicity and education centers in nature reserves; Formulate measures for the management of nature reserves and improve the construction and management of nature reserves; Actively develop eco-tourism and diversified management, and develop the economy of nature reserves. Its ultimate goal is to fully protect the forest biodiversity in Guangdong Province.
I believe that in the construction of a harmonious society in Guangdong, nature reserves will certainly become the most direct and concrete area to reflect the harmony between man and nature; In ecological construction, nature reserves play a fundamental role in maintaining national ecological security; In the protection of biological resources, nature reserves play a key role in maintaining the national strategic resource reserve and biodiversity protection. At the same time, through the construction of nature reserves, precious natural heritage resources and natural spiritual homes with biodiversity as the main body will be left to the next generation.