Tag: China

Black wattle’s new biogeographic distribution threatens flight safety in China

Black wattle, flowering trees also known as the Australian acacia, have been observed to rapidly spread around local airports in Yunnan province, southwestern China. According to the ecologists, this alien species and its extraordinary pace of invasion are to lead to new threats for both flight safety and local biodiversity. The five Chinese scientists, led by Min Liu, PhD student at Yunnan University, have their findings and suggestions for immediate measures published in the open-access journal Neobiota.

The phenomenon was investigated by the ecologists and botanists, affiliated with Yunnan University and Kunming University of Science and Technology, at Kunming’s Changshui International Airport.

The black wattle is listed as being among the ”Top 100 of the world’s worst invasive alien species” by the World Conservation Union (IUCN). Native to Australia, the species has been settled across the globe for more than 150 years owing to its multiple uses. However, its distribution and expansion are generally overlooked in China.

It is an evergreen fast growing flowering tree species, which is strongly dependent on sunlight and contributes to nitrogen fixation. This means that due to bacteria in its root system, the tree produces nitrogen compounds that help the plant grow and compete with other plants. Once dead, it would release these compounds to fertilise the soil.

During their investigation, the scientists observed a total seedling spread of 1800 m in 2013, with its peak growth taking place between June and November. Other population features such as number, density, height and ground diameter, also showed that the species had a very high invasion rate.

The authors conclude that black wattle has a strong potential to change the local vegetation structure and increase the risk of bird strikes. It is of urgent need that the situation is further assessed and the potential invasion threat at other airports around China and other parts of the world – evaluated.

“I have never found such a rapid expansion like the one of the black wattle trees at this airport in my career,” said the Head of Bird Strike Prevention Office of Changshui Airport. “These trees grow very fast and provide good shelters for local birds, which eventually increases the probability of bird strikes at our airport. So, they must be controlled.”

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Original source:

Liu M, Yang M, Song D, Zhang Z, Ou X (2016) Invasive Acacia mearnsii De Wilde in Kunming, Yunnan Province, China: a new biogeographic distribution that Threatens Airport Safety.NeoBiota 29: 53-62. doi: 10.3897/neobiota.29.7230

Tiny, record-breaking Chinese land snails fit almost 10 times into the eye of a needle

Minuscule snails defy current knowledge and scientific terminology about terrestrial “microsnails”. While examining soil samples collected from the base of limestone rocks in Guangxi Province, Southern China, scientists Barna Páll-Gergely and Takahiro Asami from Shinshu University, Adrienne Jochum, University and Natural History Museum of Bern, and András Hunyadi, found several minute empty light grey shells, which measured an astounding height of less than 1 mm.

The single known shell of Angustopila dominikae, named after the wife of the first author, was measured a mere 0.86 mm in shell height. Thus, it is considered to be perhaps the World’s smallest land snail species when focusing on the largest diameter of the shell. With very few reported instances of species demonstrating this degree of tininess, the team have described a total of seven new land snail species in their paper, published in the open access journal ZooKeys.

Another of the herein described new species, called Angustopila subelevata, measured 0.83-0.91 mm (mean = 0.87 mm) in height.

Two of the authors have previously described other species of tiny land snails from China and Korea in the same journal.

In their present paper, Dr. Pall-Gergely and his team also discuss the challenges faced by scientists surveying small molluscs, since finding living specimens is still very difficult. Thus, the evolutionary relationships between these species, as well as the number of existing species are yet little known.

“Extremes in body size of organisms not only attract attention from the public, but also incite interest regarding their adaptation to their environment,” remind the researchers. “Investigating tiny-shelled land snails is important for assessing biodiversity and natural history as well as for establishing the foundation for studying the evolution of dwarfism in invertebrate animals.”

“We hope that these results provide the taxonomic groundwork for future studies concerning the evolution of dwarfism in invertebrates,” they finished up.

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Original source:

Páll-Gergely B, Hunyadi A, Jochum A, Asami T (2015) Seven new hypselostomatid species from China, including some of the world’s smallest land snails (Gastropoda, Pulmonata, Orthurethra). ZooKeys 523: 31-62. doi: 10.3897/zookeys.523.6114