title: Evidence for the persistence of wild Ginkgo biloba (Ginkgoaceae) populations in the Dalou Mountains, southwestern China.
abstract: OBJECTIVE
  The possible persistence of wild Ginkgo biloba populations in China has long been debated but never scientifically confirmed. We test our hypothesis that the extant Ginkgo populations in the Dalou Mountains (SW China) represent fragments of the original natural Ginkgo range and offer a range of pertinent perspectives on the living fossil Ginkgo's history, prehistory, ecology, and place in human culture-all important aspects of this highly valued species.
  
  
  METHODS
  We analyzed the vegetation of the study area, determined the population age structure of Ginkgo, and compared it to existing fossil records. For supporting material, we also examined records of the lack of human presence before the mid-17th century in the area, the local people's beliefs regarding preservation of the forests and existing genetic studies.
  
  
  RESULTS
  Current species composition of Ginkgo forests in the Dalou Mountains agrees closely with floristic assemblages from fossil records bearing G. biloba. Current populations are found in habitats similar to those of fossil Ginkgo, which, as today, favored rock crevices. Female to male ratios are 3:2. Estimated ages for many of the trees show that Ginkgo was present in this area prior to human settlement and indigenous peoples of this area are unlikely to have planted Ginkgo because of traditional beliefs. Our results agree with existing genetic studies that show that these mountains were glacial refugia for G. biloba.
  
  
  CONCLUSIONS
  The corroborative evidence confirms the finding that these populations represent fragments of the original natural Ginkgo in the valley and lower mountain slopes of the Dalou Mountains.
authors: Institute of Ecology and Geobotany, Yunnan University, Kunming, China. cindyqtang@aol.com
authors: Cindy Q
authors: CQ
authors: Tang
authors: Yongchuan
authors: Y
authors: Yang
authors: Masahiko
authors: M
authors: Ohsawa
authors: Si-Rong
authors: SR
authors: Yi
authors: Arata
authors: A
authors: Momohara
authors: Wen-Hua
authors: WH
authors: Su
authors: Huan-Chong
authors: HC
authors: Wang
authors: Zhi-Ying
authors: ZY
authors: Zhang
authors: Ming-Chun
authors: MC
authors: Peng
authors: Zhao-Lu
authors: ZL
authors: Wu
mesh_terms: D005075:Biological Evolution; D002681:China; D017753:Ecosystem; D040342:Genetic Structures; D005828:Genetics, Population; D005843:Geography; D020441:Ginkgo biloba / Q000235:genetics* / Q000254:growth & development; D036226:Seedlings / Q000235:genetics / Q000254:growth & development; D013997:Time Factors; D014197:Trees