ARTÍCULO

Distribution patterns of long-lived individuals of relict plants around Fanjingshan Mountain in China: Implications for in situ conservation

H.-Y. Liao (廖洪英)¹ & M.-X. Ren (任明迅)²

¹ Tongren Forestry Bureau, CN-554300 Tongren, China
² College of Horticulture and Landscape Architecture, Hainan University, CN-570228 Haikou, China

Author for correspondence: M.-X. Ren (rensanshan@hotmail.com)

Editors: J.-Q. Liu & J. López-Pujol

ABSTRACT
Distribution patterns of long-lived individuals of relict plants around Fanjingshan Mountain in China: implications for in situ conservation.— The mountain areas in south-central China are widely recognized as refugia of relict plants during the late Neogene and Quaternary periods. In this paper, we try to explore the distribution patterns of natural habitats and to exactly locate the refugia of relict species around Fanjingshan Mountain using dendrological data of long-lived individuals (≥100 years old). Six typical relict plants were found around the mountain, i.e. Cyclocarya paliurus, Ginkgo biloba, Liriodendron chinense, Pinus massoniana, Podocarpus macrophyllus, and Taxus chinensis. The long-lived individuals were divided into three classes according to their ages: Class-I (≥500 years), Class-II (300–499 years), and Class-III (100–299 years). Our results showed that the south-west region to the mountain was the main distribution area of Class-I trees of G. biloba and T. chinensis, most of which occurring in the same small village (Yangliu Village of Yinjiang County). The north-east region harboured all the six relict species. Floristic analyses also indicated these two regions were very similar in tree growth as measured by DBH (diameter at breast height of 1.3 m). Thus, these two areas would have provided long-term suitable habitats for relict species. The south-west region, especially the small village Yangliu, should be given highest priority for in situ conservation of relict species and other rare and endangered plants. Attention should also be paid to the north-east region for its very high species diversity of relict species.
KEYWORDS: biodiversity; endemic plants; fengshui forests; glacial refugia; old trees.

Patrones de distribución de individuos longevos de plantas relictas en los alrededores de la montana Fanjingshan en China: implicaciones para su conservación in situ.

RESUMEN
Patrones de distribución de individuos longevos de plantas relictas en los alrededores de la montana Fanjingshan en China: implicaciones para su conservación in situ.— Las áreas montañosas de la región centro-sur de China están ampliamente reconocidas por su papel como refugio de plantas relictas durante la última etapa del Neógeno y el Cuaternario. En el presente trabajo se intentan explorar los patrones de distribución de los hábitats naturales y la localización exacta de los refugios para especies vegetales relictas en los alrededores de la montaña Fanjinshan, mediante el empleo de datos dendrológicos de individuos longevos (≥100 años). En el área de estudio se encontraron seis especies vegetales típicamente relictas: Cyclocarya paliurus, Ginkgo biloba, Liriodendron chinense, Pinus massoniana, Podocarpus macrophyllus y Taxus chinensis. Los individuos longevos se dividieron en tres categorías de acuerdo con su edad estimada: individuos de Clase I (≥500 años), de Clase II (300–499 años) y de Clase III (100–299 años). Nuestros resultados muestran que la región situada al suroeste de la montaña se corresponde con la principal área de distribución de los árboles de Clase I de G. biloba y T. chinensis, localizándose la mayor parte de éstos en los alrededores de una pequeña aldea (Yangliu, en el condado de Yinjiang). La región situada al noreste de Fanjinshan alberga, por su parte, las seis especies relictas, y los análisis florísticos muestran una elevada similaridad entre ambas regiones por lo que respecta al crecimiento arbóreo medido como DBH [diámetro a la altura del pecho (1,3 m)]. Por consiguiente, estas dos regiones habrían proporcionado hábitats adecuados para la supervivencia de especies relictas. La región suroeste, y en especial la aldea de Yangliu, deben recibir la máxima prioridad para la conservación in situ de especies relictas (y otras especies raras y amenazadas). La región noreste también debe priorizarse dada su elevada diversidad de especies relictas.
PALABRAS CLAVE: árboles longevos; biodiversidad; bosques fengshui; plantas endémicas; refugios glaciales.

摘要
中国梵净山周边地区孑遗植物古树分布格局：对就地保护的启示。— 中国中南部山区是广为人知的孑遗植物避难所，这些孑遗植物经历了地球最后一个大规模冰期，即第四纪冰期（约300万年前）。 在这篇文章中，我们试图通过分析梵净山周边地区孑遗植物的古树（大于或等于100年）的生长情况与地理分布格局，来解释这些孑遗植物自然生境及避难所的具体所在，并提出就地保护策略。数据主要来源于铜仁市林业局和印江县、松桃县以及江口县林业部门的野外调查结果。梵净山及周边地区自然分布着6种典型的孑遗植物：银杏（Ginkgo biloba）、鹅掌楸（Liriodendron chinense）、罗汉松（Podocarpus macrophyllus）、青钱柳（Cyclocarya paliurus）、马尾松（Pinus massoniana）、红豆杉（Taxus chinensis）。古树可根据树龄分为三级：I级是树龄不小于500年的古树；II级是指300-499年的古树；III级则包括100-299年的古树。我们发现，6个孑遗植物在梵净山的东北方向（松桃县）都有分布；梵净山西南方向则是银杏和红豆杉I级古树的主要分布区，尤其集中分布在印江县杨柳乡。植物区系相似度的分布结果也表明，这两个区的古树生长（以胸径度量）相似度很高。因此，这两个区很可能在较长时间一直保存着这些孑遗植物合适的生境。梵净山整个西部都分布着极高比例的I级古树，其中绝大多数都是银杏。可见，梵净山周围的西边和东北方向很可能长期保存着这些孑遗植物适宜的自然生境。梵净山的西南方向，尤其是杨柳乡，尤其应特别重视，可作为就地保护孑遗植物或其它珍稀濒危植物的一个首选地址。梵净山东北方向（松桃县及其与江口县临近地区）具有极高的孑遗植物物种多样性，也需给与特别保护。
关键词：生物多样性；特有植物；风水林；冰期避难所；古树。

CONTENIDOS

INTRODUCTIONTop

Fanjingshan Mountain is located at Guizhou Province (south-western China), running in a north-east–south-west direction and having an approximate area of 570 km² (GFNNRAB, 2004GFNNRAB (Guizhou Fanjingshan National Natural Reserve Administration Bureau) 2004. 贵州梵净山国家级自然保护区保护规划-可持续林业发展/保护区管理计划 [The Management Plan of Guizhou Fanjingshan National Nature Reserve. Sustainable Forestry Development Project/Protected Area Management]. Fanjinshan National Nature Reserve, Jiangkou. Retrieved December 3, 2014, from http://www.fanjingshan.cn/index1.asp). This mountain is part of the Three Gorges Region (Fig. 1), which is one of the three main biodiversity hotspots and endemism centres in China (Ying & Zhang, 1984Ying, T.-S. & Zhang, Z.-S. 1984. 中国植物区系中的特有现象–特有属的研究 [Endemism in the flora of China – Studies on the endemic genera]. Acta Phytotaxonomica Sinica, 22: 259–268 [in Chinese].; Ying, 2001Ying, T.-S. 2001. 中国种子植物物种多样性及其分布格局 [Species diversity and distribution pattern of seed plant in China]. Biodiversity Science 9: 393–398 [in Chinese].; Li et al., 2009Li, G., Shen, Z., Ying, T. & Fang, J-Y. 2009. 中国裸子植物物种丰富度空间格局与多样性中心 [The spatial pattern of species richness and diversity centres of gymnosperm in China]. Biodiversity Science 17: 272–279 [in Chinese]. http://dx.doi.org/10.3724/SP.J.1003.2009.08327; López-Pujol et al., 2011aLópez-Pujol, J., Zhang, F.-M., Sun, H.-Q., Ying, T.-S. & Ge, S. 2011a. Centres of plant endemism in China: places for survival or for speciation? Journal of Biogeography 38: 1267–1280. http://dx.doi.org/10.1111/j.1365-2699.2011.02504.x, bLópez-Pujol, J., Zhang, F.-M., Sun, H.-Q., Ying, T.-S. & Ge, S. 2011b. Mountains of southern China as “plant museums” and “plant cradles”: Evolutionary and conservation insights. Mountain Research and Development 31: 261–269. http://dx.doi.org/10.1659/MRD-JOURNAL-D-11-00058.1). The rich biodiversity in this hotspot is mainly a result of glacial refugia that existed in the area during late Neogene and Quaternary periods (Li, 1940Li, S-G. 1940. 鄂西川东湘西桂北第四纪冰川现象述要 [On the ice sheet of Quaternary glaciations in the west Hubei, east Sichuan, west Hunan, and north Guangxi provinces]. Geological Review 5: 171–184 [in Chinese].; Axelrod et al., 1996Axelrod, D. I., Al-Shehbaz, I. & Raven, P. H. 1996. History of the modern flora of China. In: Zhang, A. & Wu, S. (Eds.), Floristic characteristics and diversity of East Asian plants. China Higher Education Press, Beijing: 43–55.; Qian, 2001Qian, H. 2001. A comparison of generic endemism of vascular plants between East Asia and North America. International Journal of Plant Sciences 162: 191–199. http://dx.doi.org/10.1086/317909; López-Pujol et al., 2011aLópez-Pujol, J., Zhang, F.-M., Sun, H.-Q., Ying, T.-S. & Ge, S. 2011a. Centres of plant endemism in China: places for survival or for speciation? Journal of Biogeography 38: 1267–1280. http://dx.doi.org/10.1111/j.1365-2699.2011.02504.x). Consequently, this biodiversity hotspot is probably China’s region with the highest concentration of relict species; most of these are “living fossils” at present surviving in a small part of it original distribution area due to range contraction as a result of the late Cenozoic global cooling.

Figure 1. The location of Fanjingshan Mountain (star) and three main plant diversity centres in China (red circles). The three longest rivers of China are also indicated. [View full size] [Descargar tamaño completo]

Nowadays in Fanjingshan Mountain and its nearby regions, some wild individual or even wild populations of relict species can still be found (Axelrod et al., 1996Axelrod, D. I., Al-Shehbaz, I. & Raven, P. H. 1996. History of the modern flora of China. In: Zhang, A. & Wu, S. (Eds.), Floristic characteristics and diversity of East Asian plants. China Higher Education Press, Beijing: 43–55.; Tang et al., 2011Tang, C. Q., Yang, Y., Ohsawa, M., Momohara, A., Hara, M., Cheng, S. & Fan, S. 2011. Population structure of relict Metasequoia glyptostroboides and its habitat fragmentation and degradation in south-central China. Biological Conservation 144: 279–289. http://dx.doi.org/10.1016/j.biocon.2010.09.003, 2012Tang, C. Q., Yang, Y., Ohsawa, M. et al. 2012. Evidence for the persistence of wild Ginkgo biloba (Ginkgoaceae) populations in the Dalou Mountains, southwestern China. American Journal of Botany 99: 1408–1414. http://dx.doi.org/10.3732/ajb.1200168), including Davidia involucrata Baill., Ginkgo biloba L., Liriodendron chinense (Hemsl.) Sarg., and Metasequoia glyptostroboides Hu & W. C. Cheng (GFNNRAB, 2004GFNNRAB (Guizhou Fanjingshan National Natural Reserve Administration Bureau) 2004. 贵州梵净山国家级自然保护区保护规划-可持续林业发展/保护区管理计划 [The Management Plan of Guizhou Fanjingshan National Nature Reserve. Sustainable Forestry Development Project/Protected Area Management]. Fanjinshan National Nature Reserve, Jiangkou. Retrieved December 3, 2014, from http://www.fanjingshan.cn/index1.asp; Tang et al., 2011Tang, C. Q., Yang, Y., Ohsawa, M., Momohara, A., Hara, M., Cheng, S. & Fan, S. 2011. Population structure of relict Metasequoia glyptostroboides and its habitat fragmentation and degradation in south-central China. Biological Conservation 144: 279–289. http://dx.doi.org/10.1016/j.biocon.2010.09.003, 2012Tang, C. Q., Yang, Y., Ohsawa, M. et al. 2012. Evidence for the persistence of wild Ginkgo biloba (Ginkgoaceae) populations in the Dalou Mountains, southwestern China. American Journal of Botany 99: 1408–1414. http://dx.doi.org/10.3732/ajb.1200168). This fact indicates that Fanjingshan Mountain provided long-term relatively stable habitats for these relict plants. The field surveys also revealed a considerable number of long-lived trees (≥100 years old) of these relict plants around the mountain (Zhang, 2004Zhang, J.-L. 2004. 贵州名木古树 [Old and famous trees in Guizhou Province]. Guizhou Science and Technology Press, Guiyang. ). The places where the natural long-lived individuals occur may indicate the locations of suitable habitats for relict species (probably as “refugia within refugia”; Wang et al., 2009Wang, J., Gao, P.-X., Kang, M., Lowe, A. J. & Huang, H.-W. 2009. Refugia within refugia: the case study of a canopy tree (Eurycorymbus cavaleriei) in subtropical China. Journal of Biogeography 36: 2156–2164. http://dx.doi.org/10.1111/j.1365-2699.2009.02165.x). The frequencies and distribution patterns of these long-lived individuals can therefore be used to determine growth conditions and the nature of microhabitats for these relict species or other rare and endangered species, which is important for deciding in situ conservation sites and is of instructive significance for ex situ conservation.

MATERIALS AND METHODSTop

Data collection

Three local forestry governments surrounding the Fanjingshan Mountain—i.e. Songtao County, Jiangkou County, and Yinjiang County (Fig. 2)—had respectively carried out field surveys in summers of 2010–2012 on long-lived trees (≥100 years old) with plant scientists from universities and institutes. The reports of these surveys have not published yet but can be obtained from the local forest governments upon request. According to geographic and topographic characters, we divided the surroundings of the mountain into four regions, i.e. north-east (Songtao County), south-east (Jiangkou County), north-west (the north of Yinjiang County), and south-west (the south of Yinjiang County) (Fig. 2). The NW and SW regions were separated roughly by an expressway. The NE and SE were separated roughly by the Zhaiying and Xiaojiang rivers at the boundary of Songtao and Jiangkou counties (Fig. 2). We collected tree age and diameter at breast height (1.3 m) (DBH) for each long-lived tree.

Figure 2. Spatial distribution patterns of long-lived trees of six relict species around the Fanjingshan Mountain. The dashed lines separate the surroundings of the mountain into four geographic regions. The three sizes of symbols correspond to the three age classes (i.e. Class-I trees are represented with the largest symbol). The number of symbols is just illustrative, and does not indicate the exact number of individuals. [View full size] [Descargar tamaño completo]

Data analyses

The data of long-lived individuals were analysed separately for the four regions. Based on the national criterion, the long-lived trees can be divided into three classes: Class-I refers to trees of at least 500 years old; Class-II is trees with an age of 300–499 years, Class-III includes long-lived trees less than 300 years old. We focused our study on six widely-recognized relict plants (Figs. 2 and 3): Cyclocarya paliurus (Batalin) Iljinsk., Ginkgo biloba, Liriodendron chinense, Pinus massoniana Lamb., Podocarpus macrophyllus (Thunb.) Sweet, and Taxus chinensis (Pilg.) Rehder.

Figure 3. Long-lived trees of Ginkgo biloba (A) and Taxus chinensis (B) near a village in north-west region of Fanjingshan Mountain. Long-lived trees are often found in fengshui (“wind and water”) forests (C) surrounding villages, and sometimes they form a community (D). Some long-lived trees are removed and transplanted (E) for ornamental use and/or ex situ conservation, but now it is strictly forbidden and in situ conservation is emphasized (F). The red cloth strips on the tree were hung by villagers for wishes of long life and good luck. [View full size] [Descargar tamaño completo]

To detect the growth status of the trees, we estimated the relationship between tree age and DBH for each relict species respectively for the four regions. These data were also used to compare the habitat quality among four regions, e.g. the habitat can be assumed as of good quality if the DBH of long-lived trees increased steadily with age.

To explore the plant communities and habitat similarity among four regions, we draw the floristic similarity dendrogram according to Tang et al. (2011Tang, C. Q., Yang, Y., Ohsawa, M., Momohara, A., Hara, M., Cheng, S. & Fan, S. 2011. Population structure of relict Metasequoia glyptostroboides and its habitat fragmentation and degradation in south-central China. Biological Conservation 144: 279–289. http://dx.doi.org/10.1016/j.biocon.2010.09.003, 2012Tang, C. Q., Yang, Y., Ohsawa, M. et al. 2012. Evidence for the persistence of wild Ginkgo biloba (Ginkgoaceae) populations in the Dalou Mountains, southwestern China. American Journal of Botany 99: 1408–1414. http://dx.doi.org/10.3732/ajb.1200168) using the PAST software (Hammer et al., 2001Hammer, Ø., Harper, D. A. T. & Ryan, P. D. 2001. PAST: Paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4(1): 4 ). The values of relative DBH for long-lived individuals of Ginkgo biloba and Taxus chinensis were applied in the similarity dendrogram analysis using Euclidean and group average clustering. The other relict species were not included into this analyses because they are too few and some are absent in one or two regions.

RESULTSTop

Distribution patterns

All the information about tree age, DBH, and tree height of long-lived individuals is available in the Appendix. The age classes and spatial distributions of these plants are shown in Fig. 2 and Table 1. Ginkgo biloba and Taxus chinensis were the most common species among the long-lived trees (Figs. 2 and 3, and Table 1), while the other relict species were restricted to a few small areas. Both SW and NE regions appeared to be the accumulation centres of long-lived trees (Fig. 2). Especially the SW region harboured a large proportion of Class-I long-lived trees of G. biloba, some of which were of ≥1000 years old (Fig. 4 and Appendix). For example, six ≥1000-year-old trees and eight Class-I trees of G. biloba were found at a small site (Yangliu Town) located at the south of this region (Fig. 2). Another distribution centre of G. biloba is the NW region, where three 1000-year-old trees and another five Class-I trees were found (Figs. 2 and 4, and Appendix).

The eastern side of Fanjingshan Mountain, especially the SE region, had fewer long-lived trees as compared with the other regions (Fig. 2 and Appendix). Only four Class-I trees of G. biloba occurred at the NE region, while no Class-I trees were found in the SE region (Fig. 2). All the six relict species were found in the NE region and most individuals grew along the east fringe of the mountain and the boundary with the SE region, where several small rivers and valleys occur. Compared to G. biloba, T. chinensis had much fewer Class-I trees and no trees were older than 600 years (Fig. 4). The distribution centres of T. chinensis were quite similar to G. biloba, located both at the NE region and the west side of the mountain.

Figure 4. Relation of DBH (diameter at breast height) and tree age of Taxus chinensis (A) and Ginkgo biloba (B) in four regions around Fanjingshan Mountain. The other four relict plants have very few individuals and are not shown here. [View full size] [Descargar tamaño completo]

Correlation of DBH and tree age

The DBH increased with the age more quickly in G. biloba than in T. chinensis (Fig. 4A, B) for long-lived trees below 600-year old. For G. biloba trees with an age of >600 years, DBH increased very slowly (Fig. 4B).

For G. biloba, the long-lived trees from NW region showed a relatively larger DBH than those from the other three regions (Fig. 4B). For T. chinensis, although the DBH values were similar among the four regions, these increased more quickly in trees from NE region compared to the other regions. Consequently, the long-lived trees at the north side to the mountain had relatively larger DBH values for both relict species.

Region similarity

The dendrogram showed that the SW and NE regions were the most similar regarding the DBH of long-lived trees (Fig. 5). The SE region was clustered as the sister group of SW and NE regions, whereas the NW region is the most dissimilar one (Fig. 5).

Figure 5. Similarity dendrogram using Euclidean and group average clustering for the four regions based on the diameter at breast height (DBH) of both Ginkgo biloba and Taxus chinensis. [View full size] [Descargar tamaño completo]

Grouping of long-lived trees

We also found that some long-lived trees were growing in groups (Fig. 3C, D). For example, many long-lived trees were found in fengshui (“wind and water”) forests surrounding villages in the valley (Fig. 3C), which were well protected by local residents. Isolated long-lived trees usually occurred near villages (Fig. 3A) or farmlands (Fig. 3B), and some were regarded as “God trees” by local residents for good luck and long life (Fig. 3F).

DISCUSSIONTop

Our data showed that the west side and the NE region around Fanjingshan Mountain are main distribution sites of long-lived trees and can be seen as the real stable natural habitats for relict species such as G. biloba and T. chinensis. Such information has significant implications for conservation of these “living fossils” and local ecosystems.

All the six relict plants can be found at the NE region to the Fanjingshan Mountain (Fig. 2 and Appendix). This pattern is probably the result from the evolutionary history and demographic dynamics of relict plants during glacial periods. Fanjingshan Mountain has an altitude of >2000 m and would have acted as a main refugium for various plants during the last three million years (Qian, 2001Qian, H. 2001. A comparison of generic endemism of vascular plants between East Asia and North America. International Journal of Plant Sciences 162: 191–199. http://dx.doi.org/10.1086/317909; López-Pujol et al., 2011bLópez-Pujol, J., Zhang, F.-M., Sun, H.-Q., Ying, T.-S. & Ge, S. 2011b. Mountains of southern China as “plant museums” and “plant cradles”: Evolutionary and conservation insights. Mountain Research and Development 31: 261–269. http://dx.doi.org/10.1659/MRD-JOURNAL-D-11-00058.1). During the glacial periods of the Quaternary, most parts of China were much colder than at present (Li, 1940Li, S-G. 1940. 鄂西川东湘西桂北第四纪冰川现象述要 [On the ice sheet of Quaternary glaciations in the west Hubei, east Sichuan, west Hunan, and north Guangxi provinces]. Geological Review 5: 171–184 [in Chinese].), and only the mountainous areas with large altitudinal gradients provided opportunities and habitats for the plants to survive. The Fanjingshan Mountain is at the middle point between East and West China (Fig. 1) and probably is among the first stop-off sites when the plants retreated from the eastern lowlands. Therefore, deep valleys of the NE side of Fanjingshan Mountain are probably one of the main survival places of these relict species during their range contraction in the glacial periods (Ying & Zhang, 1984Ying, T.-S. & Zhang, Z.-S. 1984. 中国植物区系中的特有现象–特有属的研究 [Endemism in the flora of China – Studies on the endemic genera]. Acta Phytotaxonomica Sinica, 22: 259–268 [in Chinese].; Ying, 2001Ying, T.-S. 2001. 中国种子植物物种多样性及其分布格局 [Species diversity and distribution pattern of seed plant in China]. Biodiversity Science 9: 393–398 [in Chinese].; Li et al., 2009Li, G., Shen, Z., Ying, T. & Fang, J-Y. 2009. 中国裸子植物物种丰富度空间格局与多样性中心 [The spatial pattern of species richness and diversity centres of gymnosperm in China]. Biodiversity Science 17: 272–279 [in Chinese]. http://dx.doi.org/10.3724/SP.J.1003.2009.08327; López-Pujol et al., 2006López-Pujol, J., Zhang, F.-M. & Ge, S. 2006. Plant biodiversity in China: richly varied, endangered, and in need of conservation. Biodiversity and Conservation 15: 3983–4026. http://dx.doi.org/10.1007/s10531-005-3015-2, 2011aLópez-Pujol, J., Zhang, F.-M., Sun, H.-Q., Ying, T.-S. & Ge, S. 2011a. Centres of plant endemism in China: places for survival or for speciation? Journal of Biogeography 38: 1267–1280. http://dx.doi.org/10.1111/j.1365-2699.2011.02504.x, bLópez-Pujol, J., Zhang, F.-M., Sun, H.-Q., Ying, T.-S. & Ge, S. 2011b. Mountains of southern China as “plant museums” and “plant cradles”: Evolutionary and conservation insights. Mountain Research and Development 31: 261–269. http://dx.doi.org/10.1659/MRD-JOURNAL-D-11-00058.1). The SE region, however, have much fewer long-lived trees (Fig. 2); this region is mainly consisting of lowlands without deep valleys (GFNNRAB, 2004GFNNRAB (Guizhou Fanjingshan National Natural Reserve Administration Bureau) 2004. 贵州梵净山国家级自然保护区保护规划-可持续林业发展/保护区管理计划 [The Management Plan of Guizhou Fanjingshan National Nature Reserve. Sustainable Forestry Development Project/Protected Area Management]. Fanjinshan National Nature Reserve, Jiangkou. Retrieved December 3, 2014, from http://www.fanjingshan.cn/index1.asp) having, thus, a very limited role as a refugium (i.e. plant species had less opportunities to track the climatic changes). Furthermore, the SE region is the main place for tourists entering Fanjingshan Mountain and some habitats for relict plants have been destroyed due to road and hotel construction (GFNNRAB, 2004GFNNRAB (Guizhou Fanjingshan National Natural Reserve Administration Bureau) 2004. 贵州梵净山国家级自然保护区保护规划-可持续林业发展/保护区管理计划 [The Management Plan of Guizhou Fanjingshan National Nature Reserve. Sustainable Forestry Development Project/Protected Area Management]. Fanjinshan National Nature Reserve, Jiangkou. Retrieved December 3, 2014, from http://www.fanjingshan.cn/index1.asp).

Although the NE region is the area with highest species diversity of relict plants, the distribution centre of long-lived trees, especially the very old trees (Class-I and Class-II) is at the west side of the mountain (Fig. 2 and Table 1). A reason might be that the western surrounding regions are well protected by the mountain from the cold winds. and thus the habitats would have remained more stable than in the eastern side. This is probably why the west side of the mountain, including NW and SW regions, has much more Class-I trees, some of which are >1000 years old (Fig. 4 and Appendix).

Most Class-I and other long-lived trees in the SW region were found in a small village named Yangliu (more than 90% Class-I trees of G. biloba and T. chinensis grew at this village; Fig. 2). Recruits of these long-lived trees can be also found near the trees or at very close sites (H.-Y. Liao, pers. obs.). This information indicates that this place probably constitutes a long-term stable habitat for these relict species or other similar relict plants. Two additional scenarios can also explain the high occurrence of long-lived trees in this small village. First, the village is in a deep valley, far away from intense human activities. Second, the local residents of Yangliu Village are largely belonging to ethnic minorities including Tujia and Miao (GFNNRAB, 2004GFNNRAB (Guizhou Fanjingshan National Natural Reserve Administration Bureau) 2004. 贵州梵净山国家级自然保护区保护规划-可持续林业发展/保护区管理计划 [The Management Plan of Guizhou Fanjingshan National Nature Reserve. Sustainable Forestry Development Project/Protected Area Management]. Fanjinshan National Nature Reserve, Jiangkou. Retrieved December 3, 2014, from http://www.fanjingshan.cn/index1.asp); these communities normally protect big and long-lived trees as “God trees” for long life or good luck (Fig. 3F) but also protect groups of long-lived trees as fengshui forests for environmental safety and good living conditions (Fig. 3C). Therefore, Yangliu Village should be given highest priority for in situ conservation, not only for its high diversity of long-lived trees but also for its stable habitats that are protected by local residents.

Although the ethnic minorities usually protect trees around their villages, they also utilize the mountain plant resources directly, such as fuelwood gathering and burning grass in fields to clear and fertilize soils (GFNNRAB, 2004GFNNRAB (Guizhou Fanjingshan National Natural Reserve Administration Bureau) 2004. 贵州梵净山国家级自然保护区保护规划-可持续林业发展/保护区管理计划 [The Management Plan of Guizhou Fanjingshan National Nature Reserve. Sustainable Forestry Development Project/Protected Area Management]. Fanjinshan National Nature Reserve, Jiangkou. Retrieved December 3, 2014, from http://www.fanjingshan.cn/index1.asp; Wandersee et al., 2012Wandersee, S. M., An, L., López-Carr, D. & Yang Y. 2012. Perception and decisions in modeling coupled human and natural systems: A case study from Fanjingshan National Nature Reserve, China. Ecological Modelling 229: 37–49. http://dx.doi.org/10.1016/j.ecolmodel.2011.08.004). Recently, the mountain is experiencing rapid changes in land use and forest cover due to tourism, timber harvesting, and road construction (GFNNRAB, 2004GFNNRAB (Guizhou Fanjingshan National Natural Reserve Administration Bureau) 2004. 贵州梵净山国家级自然保护区保护规划-可持续林业发展/保护区管理计划 [The Management Plan of Guizhou Fanjingshan National Nature Reserve. Sustainable Forestry Development Project/Protected Area Management]. Fanjinshan National Nature Reserve, Jiangkou. Retrieved December 3, 2014, from http://www.fanjingshan.cn/index1.asp; Wandersee et al., 2012Wandersee, S. M., An, L., López-Carr, D. & Yang Y. 2012. Perception and decisions in modeling coupled human and natural systems: A case study from Fanjingshan National Nature Reserve, China. Ecological Modelling 229: 37–49. http://dx.doi.org/10.1016/j.ecolmodel.2011.08.004). Some long-lived trees were also be transplanted to cities for their commercial value (Fig. 3F). All these activities have the potential to seriously affect rare and endangered plants, particularly long-lived trees. This is probably why many long-lived trees are now only found in the protected fengshui forests near villages (Fig. 3A, C). Therefore, it is necessary to set up several suitable sites in this village or nearby places for in situ conservation of these relict species or other rare and endangered plants. Fortunately, reforestation programs from national and local governments, such as the Natural Forest Conservation Program (NFCP) and the Grain-to-Green Program (GTGP), were carried out since about one decade ago (GFNNRAB, 2004GFNNRAB (Guizhou Fanjingshan National Natural Reserve Administration Bureau) 2004. 贵州梵净山国家级自然保护区保护规划-可持续林业发展/保护区管理计划 [The Management Plan of Guizhou Fanjingshan National Nature Reserve. Sustainable Forestry Development Project/Protected Area Management]. Fanjinshan National Nature Reserve, Jiangkou. Retrieved December 3, 2014, from http://www.fanjingshan.cn/index1.asp; Liu et al., 2008Liu, J., Li, S., Ouyang, Z., Tam, C. & Chen, X. 2008. Ecological and socioeconomic effects of China’s policies for ecosystem services. Proceedings of the National Academy of Sciences of the United States of America 105: 9477–9482. http://dx.doi.org/10.1073/pnas.0706436105; Wandersee et al., 2012Wandersee, S. M., An, L., López-Carr, D. & Yang Y. 2012. Perception and decisions in modeling coupled human and natural systems: A case study from Fanjingshan National Nature Reserve, China. Ecological Modelling 229: 37–49. http://dx.doi.org/10.1016/j.ecolmodel.2011.08.004). The NFCP is geared to protect forests, water, and soil for environmental safety and biodiversity (Li, 2004Li, W-H. 2004. Degradation and restoration of forest ecosystems in China. Forest Ecology and Management 201: 33–41. http://dx.doi.org/10.1016/j.foreco.2004.06.010; Wandersee et al., 2012Wandersee, S. M., An, L., López-Carr, D. & Yang Y. 2012. Perception and decisions in modeling coupled human and natural systems: A case study from Fanjingshan National Nature Reserve, China. Ecological Modelling 229: 37–49. http://dx.doi.org/10.1016/j.ecolmodel.2011.08.004). The GTGP aims to plant trees on steep slopes where were once used by farmers as croplands, and the farmers are compensated through cash or foodstuff (Feng et al., 2005Feng, Z., Yang, Y., Zhang, Y., Zhang, P. & Li, Y. 2005. Grain-for-green policy and its impacts on grain supply in West China. Land Use Policy 22: 301–312. http://dx.doi.org/10.1016/j.landusepol.2004.05.004).

In conclusion, our data suggest that, although the Fanjingshan Mountain (which is a National Natural Reserve) is the main distribution region of rare and endangered plants including relict species, the surrounding places are also of conservation value due to their large number of long-lived trees of relict plants and the primaeval habitats protected by local residents. We should not only protect the local biodiversity within the limits of the natural reserve, but also pay enough attention to the rare and endangered species that occur out of the range of the reserve.

ACKNOWLEDGEMENTSTop

We thank the staff from Tongren Forestry Bureau and forestry bureaus of Yinjiang, Songtao, and Jiangkou counties, for sharing their deep knowledge on old trees around the Fanjingshan Mountain. We also thank two reviewers for their helpful comments. This work was supported by the National Natural Science Foundation of China (Grant number: 31170356) and a start-up fund from Hainan University to M.-X. Ren (kyqd1501).

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