2.1 | Data collection
Several search engines were used to identify publications with abstracts that contain the Latin or Chinese names of the pines as well as the words “seed” and “seed dispersers”. These search engines included Web of Science, Biological Abstracts, China National Knowledge Internet, and Wildlife & Ecology Studies Worldwide. We retained only articles, reviews, and theses published in English and Chinese. After searching, 23 Chinese articles and 20 English articles were selected in terms of their contained information regarding seed dispersal of the eight specified species of pines (Table 3). In each study, the seed dispersers of the large-seeded pines were recorded.
To the best of our knowledge, the detailed pines and animal ranges available were Flora of China (Zheng & Fu, 1978) and Fauna Sinica (Luo, 2000; Zhang, 2007), which were published by Science Press and hosted by the Chinese Academy of Science. Although these data are considered a landmark for studies conducted on the ecology and conservation of pines, rodents, and birds, updating the databases is demanding, but neglecting added information can be detrimental to conservation efforts (Hughes, 2017). In addition, we also referred to Pinus dabeshanensis and its Origin (Peng & Jiang, 1999), Tibet Vegetation (Chinese Academy of Sciences, 1988), Flora and Vegetation Geography of China (Chen, 2014) and Floristics of Seed Plants from China (Wu, 2011) as literary references for the distribution of pines, while A Checklist on the Classification and Distribution of the Birds of China (Third Edition) (Zheng, 2017), China’s Mammal Diversity and Geographic Distribution (Jiang et al., 2015), and Study on Rodents in Typical Semi-desert and Desert Areas of China (Wu et al., 2008) were the literary references for the distribution of seed dispersers.
We also queried the distribution information of these species from Global Biodiversity Information Facility (GBIF, 2020) (https://www.gbif.org/) as a supplement (see “Data available”), we obtained the distribution information of eight species of pines with geographical coordinates in China, and screened the information one by one. The records that were wrongly classified due to the wrong name of species were eliminated, and the effective records of each species were retained. There were no records of P. geraedana , 3 of P. pimila , 74 of P. bungeana , 505 of P. armandii , 22 ofP. koraiensis and 28 of P. fenzeliana (excluding 106 records of P. kwangtungens , which were classified as Latin name errors). The species information on GBIF were obtained from the contributions of biologists and field researchers through time, but for species with poor habitat conditions, there would be a lack of information, while the habitat that is accessible to humans would have widely studied species. However, the distribution data could be inaccurate with differences between the GBIF data and the Chinese monograph. Hence, we chose to follow the data provided in Flora of China, Fauna Sinica, and local plant and animal record books, as mentioned previously.