Expert interview: eucalyptus drought? Lack of basis!

People's Daily published the Yanshu Research Center of the State Forestry Administration

Expert Interview: Is Eucalyptus Causing Drought? No Evidence!

Interview Guests

Xie Yaojian: Chairman of the China Forestry Society's Eucalyptus Professional Committee

Chen Shaoxiong: Researcher, Yushu Research and Development Center, State Forestry Administration

Is eucalyptus really a "water pump" as some people claim? Xie Yaojian, chairman of the Eucalyptus Professional Committee at the China Forestry Society, explained that currently, eucalyptus plantations cover an area of 2.6 million hectares, with about 80% located in coastal provinces like Guangdong, Guangxi, Hainan, and Fujian. In contrast, Yunnan, Sichuan, Hunan, and Jiangxi have much smaller areas of eucalyptus planting. According to studies, for every kilogram of dry biomass produced, pine trees consume around 1,000 liters of water, while species such as acacia, Dalbergia, bananas, and coffee require more than 800 liters. Eucalyptus, however, only needs 510 liters. This shows that eucalyptus has a very high water use efficiency. Although it uses more water overall due to its fast growth, it doesn't create a water crisis in suitable regions.

Chen Shaoxiong, a researcher from the State Forestry Administration's Eucalyptus Research and Development Center, also refutes the idea that eucalyptus is a "water pump." He mentioned that between 1999 and 2003, experts from China and Australia conducted a study on "eucalyptus and water" in Tunxi and Leizhou, Guangdong. The results showed that during the rainy season, eucalyptus consumed less than half the amount of rainfall. In the dry season, its water consumption was roughly equal to the rainfall. The roots of eucalyptus are mainly found within 0.5 to 1 meter underground. In areas with annual rainfall over 800 mm, the roots don’t tap into groundwater. Even during droughts, they only absorb moisture up to 4 meters deep. Additionally, eucalyptus has a low leaf area index, which limits transpiration and reduces water use.

Xie Yaojian added that while forests can improve local microclimates, their impact on large-scale climate patterns is minimal. The southwest region is a transitional zone for various monsoon systems, with distinct wet and dry seasons. Forests there act as a buffer rather than a major climate driver. Therefore, the rumors that eucalyptus caused droughts in the southwest lack scientific support.

Eucalyptus, along with poplars and pines, is known as one of the world’s three fastest-growing tree species. China started introducing eucalyptus in 1890, and after the 1980s, eucalyptus plantations expanded rapidly. By 2009, eucalyptus had become a key species for fast-growing and high-yield forests in southern China, and the most important wood source for pulp and fiber in the region. These plantations play a crucial role in ensuring China's timber security. It is predicted that by 2015, China's wood consumption will reach 330-340 million cubic meters, but domestic supply will only meet 190 million. Eucalyptus plantations account for less than 3% of forest land but provide 18% of the country’s timber demand.

Attachment: State Forestry Administration Yanshu Research Center: Eucalyptus is Not a Water Pump

Eucalyptus originates from Australia, Indonesia, and the Philippines. China has been cultivating it for over 110 years and now considers it a strategic species for fast-growing and high-yield forests in southern China. Alongside poplars and pines, eucalyptus is one of the three fastest-growing tree species globally. It is known for its adaptability, rapid growth, short rotation period, and resistance to pests and diseases. China currently has 2.3 million hectares of eucalyptus plantations, making up 8% of the country’s planted forests. Despite myths such as “it’s a water pump,” “it’s a drug pump,” or “no birds, no grass under the trees,” the Yanshu Research Center aims to provide a scientific and objective explanation.

Description of the Ecological Impact of Eucalyptus

(1) Eucalyptus is not a "water pump." Scientific research shows that for each kilogram of dry biomass, pine trees need 1,000 liters of water, while acacia, rosewood, bananas, and coffee require over 800 liters. Eucalyptus only needs 510 liters, indicating high water use efficiency. Though eucalyptus consumes more water due to its fast growth, it does not cause a water crisis in suitable areas. For example, on the Leizhou Peninsula, eucalyptus transpiration accounts for about 1/3 of annual rainfall, and total transpiration plus evaporation is 1,000–1,100 mm per year, far below the 1,500 mm annual rainfall. This means it doesn’t reduce groundwater levels. Moreover, the Sino-Australian project “Eucalyptus and Water” showed that eucalyptus forests in Leizhou help recharge groundwater, offering some water conservation benefits.

(2) Eucalyptus is non-toxic. It is not only safe for humans and animals but also directly used by them. Koalas, for instance, live exclusively on eucalyptus leaves in Australia. If eucalyptus were toxic, how could they survive? Furthermore, Australian cities are surrounded by eucalyptus forests, and their drinking water sources are often near these trees. Australians have never reported poor water quality or toxicity in eucalyptus areas. Eucalyptus oil, extracted from the leaves, is used in cosmetics and pharmaceuticals, including many medicinal tablets.

(3) Scientific management prevents soil degradation. While eucalyptus plantations may temporarily reduce soil fertility due to intensive growth and high mineral absorption, this is manageable. Farmers sometimes remove all litter, causing soil depletion. However, this issue can be resolved through proper nutrient management and formula fertilization. Soil fertility decline is not as severe as claimed, and with scientific methods, the problem can be addressed effectively.

Schedule: Comparison of Mineral Nutrients Absorbed and Carried Away by Eucalyptus and Other Crops

Species absorbed (kg/ha/year) carried away (kg/ha/year)

The table above shows that eucalyptus does not absorb the most nutrients compared to other crops. Therefore, there is no scientific basis for claims that eucalyptus causes serious soil degradation.

Taking Zhanjiang as an example, the Leizhou Forestry Bureau, established in 1954, has planted eucalyptus for over 50 years, covering 700,000 mu, with 90% being eucalyptus plantations. Some people might think the land is ruined, but instead, the forest land is improving. The productivity of eucalyptus plantations has increased significantly. Before the 1970s, the yield was only 0.3 cubic meters per mu per year, but now it reaches 1.5 cubic meters per mu annually. This improvement is due to technological advancements, new varieties, formula fertilization, and returning litter to the soil, proving that more eucalyptus is better when managed properly.

(4) There is also biodiversity under eucalyptus forests. As an artificial ecosystem, eucalyptus plantations are intensively managed and consist of pure forests, so their biodiversity is simpler than natural ecosystems. However, they are not "completely barren." According to surveys by Xie Zhengsheng from South China Agricultural University, there were 150 species of 127 genera and 61 species under eucalyptus forests on the Leizhou Peninsula, showing that eucalyptus plantations do not reduce local plant diversity. Hong Changfu of the Changtai Yanxi Forest Farm in Fujian Province studied the undergrowth vegetation of giant eucalyptus forests in Zhangzhou, finding 29 families, 49 genera, and 53 species, further supporting that there is no basis for the claim that "there is no grass under eucalyptus."

In Australia, where eucalyptus is native, the forests are rich in flora and fauna, with kangaroos, birds, and reptiles living among dense shrubs and weeds. In some cases, the undergrowth is sparse due to reasons like excessive planting density, lack of sunlight, or heavy manual weeding. These issues are not due to eucalyptus itself but to improper management practices.

Eucalyptus brings significant social, economic, and ecological benefits. Socially, it creates employment opportunities across the entire value chain, from seedling production to processing and utilization. It is estimated that four jobs are created per hectare of eucalyptus plantation. Additionally, farmers learn modern forestry techniques, enhancing labor quality and promoting rural development.

Economically, eucalyptus wood is widely used in papermaking, panel manufacturing, construction, furniture, and landscaping. Its economic returns are high, attracting many investors in southern China to develop eucalyptus plantations.

Ecologically, eucalyptus plantations act as carbon sinks, absorbing 9 tons of COâ‚‚ per hectare annually while releasing oxygen. Planting eucalyptus on degraded land improves soil structure, increases biomass, and enhances the local microclimate. Once a barren region, the Leizhou Peninsula saw its forest coverage increase from 8% to 24% after large-scale eucalyptus planting, significantly improving the environment and becoming an important agricultural hub.

New ErP Led Strip Light

Rhein Lighting has developed a line of the high voltage 2835 Led Strip Light which is perfect for home, office and outdoor decoration. The light strip has multiple colors such as white, red, blue, yellow, green and RGB etc. The strip light has clear PVC tubing, which is flexible, transparent and durable and it can be shaped, formed or bent in any angle to perfectly fit the space being decorated. You can customize the length of the LED light, and cut the LED to any length you want along the cutting mark without damage.

The ErP broadened the range of products that were covered in EuP. Earlier only directly energy-consuming (or using) products were covered. Now ErP directive also covers the products related to energy. This could be for example water-saving taps, etc.The idea is to cover the whole product supply chain: design stage, production, transport, packaging, storage, etc.

Rhein Lighting is specialized in the design and manufacture of led panel downlight, led slim down light, backlit Led Panel Light , led rope light, led strip light,Led Neon Flex, Led Neon Stripe, ETL Listed Led Strip Light, led plant light and Led Grow Light etc.

ErP Led Strip,high efficency Led Strip Lights, ErP Led Lights

Rhein Lighting Technology Co.,Ltd. , https://www.rheinlighting.com