On 30–31 January 2016 China's Panzhihua Cycad National Nature Preserve successfully carried out its 4th round of prescribed fire to improve the habitat of the threatened Panzhihua cycad Cycas panzhihuaensis. This cycad is categorized as Vulnerable on the IUCN Red List and as a Class I National Protected Plant of China. The number of populations has shrunk from 16 to one and the size of the one remaining population has shrunk by more than 80% over 3 generations as a result of poaching during the 1980s and habitat destruction by mining activities.
The Panzhihua cycad is restricted to the hot, dry savannah along the valleys of the Jinsha River and its tributaries in and around Panzhihua City. This habitat has been subjected historically to frequent wildfires. However, since the establishment of the area as a municipal preserve in 1983 (upgraded to a National Nature Preserve in 1996), fire has been excluded in accordance with national policy to prevent fires in all protected areas. After more than 2 decades without fire the Panzhihua cycad population within the preserve started to show signs of decline as a result of competition with trees. Permission was therefore obtained from the State Forestry Administration to carry out prescribed burning of 3.5 ha in 2010, 10 ha in 2011, and 5.1 ha in 2012, in north, south and south-east-facing areas, respectively. However, non-burn controls were not studied and therefore the effects of the fires remained unclear.
The 4th prescribed fire, however, was carried out in areas with known time-to-last-fire and included non-burn control plots. In addition, 1 cm thick steel plates painted with 19 temperature sensitive paints (107–538°C) were placed at ground level throughout the 24 burn areas to measure fire intensity. A replicated seed experiment was set up to examine the effect of fire on seed germination rates. The nature preserve harbours a total of 521 plant species from 111 families and 361 genera, including 25 other threatened plants, and the research will also provide information on the response of these plants to fire.
Knowledge of the effect of fire on the Panzhihua cycad will be used to design a management plan for the species and will also provide scientific data for a reconsideration of the policy on prescribed fire in nature reserves, as certain habitat types and species are dependent upon periodic burning for their continued existence. A programme to introduce fire periodically, under controlled conditions, will help to conserve C. panzhihuaensis and its remaining habitat as well as other species and habitats that evolved with and depend upon fire.
H. Liu acknowledges support from the Guangxi Science and Technology Bureau (grant no 12217-04).
