Introduction

Forests protect land and water resources,support biological diversity,and mitigate climate change(Mayer et al.2005).However,tropical rainforests are shrinking throughout the world(Gaino et al.2010)because of extensive deforestation,agricultural cultivation,and tourism development;for example,tropical forests on Hainan Island were found to be continuously shrinking(Zhai et al.2014).Hainan Island possesses high Plant Diversity with about 4200 species,630 of which are endemic to the island,including 50 endangered species(Lopez-Pujol et al.2006).However,the forest cover in Hainan Island has undergone three major change stages since 1950(see Supplementary Appendix A:Fig.S1)because of deforestation and degradation caused by excessive logging,human habitation,and large-scale agricultural activities(Zhang et al.2000;Lopez-Pujol et al.2006).The loss of tropical rainforests,especially Dipterocarp forests,the typical tropical forests in Asia(Bunyavejchewin et al.2003),has led to a decrease in the size and number of plant populations over the past fi ve decades on Hainan.

Table 1 Detailed information and genetic diversity of eleven investigated Vatica mangachapoi populations on Hainan Island

LD low disturbance,MD moderate disturbance,HD high disturbance Na,observed number of alleles;h,Nei’s(1973)gene diversity;I,Shannon’s information index;PPB,percentage of polymorphic bands

Population Longitude/E Genetic diversity index Na h I PPB(%)Jianfengling 7(JFL7) 108°58′394′ 18°44′393′ 235–269 LD 25 1.755 ± 0.432 0.201 ± 0.180 0.315 ± 0.249 75.50 Kafaling 1(KFL1) 109°19′572′ 18°41′844′ 628–713 LD 23 1.796 ± 0.405 0.230 ± 0.182 0.356 ± 0.250 79.60 Ganshiling 1(GSL1) 109°39′999′ 18°22′666′ 206–233 LD 43 1.816 ± 0.389 0.238 ± 0.183 0.366 ± 0.252 81.60 Bawangling 4(BWL4) 109°05′500′ 19°06′469′ 195–217 LD 41 1.878 ± 0.330 0.258 ± 0.170 0.399 ± 0.230 87.80 Wenchang 1(WC1) 110°41′068′ 19°32′589′ 32–77 MD 20 1.708 ± 0.457 0.225 ± 0.191 0.342 ± 0.269 64.30 Sanyan 1(SY1) 109°38′757′ 18°14′968′ 229–275 MD 30 1.806 ± 0.397 0.215 ± 0.171 0.338 ± 0.237 80.60 Wanning 1(WN1) 110°14′895′ 18°39′364′ 5–10 MD 55 1.847 ± 0.362 0.254 ± 0.184 0.388 ± 0.249 84.70 Ganshiling 6(GSL6) 109°38′504′ 18°23′095′ 65–118 HD 20 1.602 ± 0.492 0.184 ± 0.189 0.282 ± 0.270 60.20 Dongfang 1(DF1) 109°02′056′ 18°49′662′’ 191–228 HD 25 1.663 ± 0.475 0.204 ± 0.189 0.312 ± 0.268 66.30 Tongshi 1(TS1) 109°27′212′ 18°56′286′ 471–502 HD 25 1.663 ± 0.475 0.198 ± 0.189 0.305 ± 0.267 66.30 Bawangling 1(BWL1) 109°05′962′ 19°06′631′ 183–191 HD 13 1.551 ± 0.500 0.172 ± 0.183 0.266 ± 0.266 55.10 Mean – – – – 29 1.735±0.101 0.216±0.026 0.334±0.040 72.90 Total/species level – – – – 320 2.000±0.000 0.294±0.162 0.449±0.208 100.00 Latitude/N Altitude/m Disturbed degree Sample size

Genetic diversity is on the core form of biodiversity.High genetic diversity increases the adaptive potential of species to the ongoing environmental changes(Jump et al.2009).Loss of genetic diversity could make those small populations more vulnerable to extinction in fragmented habitats(Aguilar et al.2008).Moreover,current remnant populations might re fl ect historical forest composition.Suf fi cient information,such as the level of genetic diversity among populations,is helpful for identifying priority regions,reinforcement of remnant populations,re-introduction,ex situ culture and seed collection(Luo et al.2011).

Over-exploitation of forests have accelerated biodiversity losses and genetic erosion(Lopez-Pujol et al.2006;Gaino et al.2010;Manohara et al.2010).Based on previous research on the effects of forest fragmentation derived from excessive deforestation on plant genetic diversity(Aguilar et al.2008;Dai et al.2013)and the fact of long-term natural forest conversion on Hainan Island,we hypothesize that excessive deforestation over the past decades on Hainan Island could result in negative effects on the genetic diversity of long-lived trees.

多数“玩阴”之举，都戴上了“惺惺相惜”的面具，令人防不胜防。黄鼠狼给鸡拜年，是阴；引蛇出洞，瓮中捉鳖，是阴；当面拥抱，背后使枪，是阴；来说是非者，便是是非人，是阴；有酒有肉亲兄弟，急难何曾见一人，是阴；借嘘寒问暖之际煽阴风点鬼火，更是阴……被“阴”者当初以为遇到知己，不胜感激涕零，托付重任、倾吐衷肠、一泻胸中块垒；岂知一旦利害攸关，“知音”原形毕露：“跳踉大，断其喉，尽其肉，乃去。”——此时方知被“玩”、被“阴”，木已成舟，悔之晚矣。另一边厢，“玩阴”者鸣锣收兵，弹冠相庆。

To test the assumption,Vatica mangachapoi Blanco(Dipterocarpaceae)was used in the present study.V.mangachapoi is a typical slow-growing and long-lived perennial tree(Chen 1964),and the mixed V.mangachapoi forest is the dominant type of tropical evergreen monsoon rainforest on Hainan Island(Ding et al.2006;Dai et al.2008).As one of dominant family of tropical rainforest and the foremost coastal protective forest in Hainan Island,V.mangachapoi is notable for its economic and ecological signi fi cance.

The tree is widespread in various habitat types on Hainan Island and is common on dry ridges(Ashton 1998).However,the population of V.mangachapoi on Hainan Island has been drastically reduced by overexploitation in the past century.The genetic variability of V.mangachapoi and the negative impacts of excessive deforestation on V.mangachapoi forests are closely linked to the changes of the total structure of rainforests on Hainan Island.

Fig.1 Sample sites of the 11 populations of V.mangachapoi investigated on Hainan Island.The code and origin of populations refers to Table 1

Vatica mangachapoi grows slowly(Chen 1964),and it was once widespread and continuous throughout Hainan Island(Ashton 1998).Combining the natural forest changes history since the early 1950s(Appendix A:Fig.S1),we inferred that geographical pattern among the present populations of V.mangachapoi(Fig.1)was driven by the longterm historical anthropogenic landscape fragmentation,but not by the natural geographical isolation.Therefore,present geographic distance of V.mangachapoi can re fl ect the human disturbance level of the existing populations.To test thegeneticisolationbydistance(IBD),theMantelstatistical test(Breinholtetal.2009;FatemiandGross2009)ofthe999 permutations by GenAlEX was conducted,using pair-wise population genetic distance(ΦPT)and pair-wise populations geographic distance matrices.

Materials and methods

Species studied and sampling

洪口乡鼻音韵尾的类型与宁德城乡各方言点存在区别，与相连的周宁方言一致，应该是受周宁方言影响的结果，三套鼻音韵尾中 [m]尾先消失，保留[n、ŋ]尾。

According to its natural distribution and population size,11 distinct wild populations(without being replanted by humans)of V.mangachapoi were identi fi ed in nine key forest regions throughout the species’main distribution range on Hainan Island in the present study(Fig.1;Table 1).Except for the populations in Dongfang County 1(DF1),Tongshi County 1(TS1),and Wenchang County 1(WC1),the other eight populations are located in nature reserves.However,all studied populations have suffered some degree of historical disturbances in the past 50 years.

A total of 98 polymorphic loci were ampli fi ed from 320 sampled individuals from the 11 natural populations of V.mangachapoi across Hainan Island,using 10 pairs of ISSR primers(Supplementary Appendix C:ISSR data;Supplementary Appendix A:Fig.S3),which were screened from 51 pairs of ISSR primers.The number of bands of each polymorphicprimervariedfrom six(UBC828and UBC836)to 13(UBC818,UBC834 and UBC840)(Supplementary Appendix A:Table S1).Most of the ISSR primers,except UBC836(PPB=83.3%),ampli fi ed 100%polymorphic bands.The genetic diversity(Na,h,I,and PPB)within eleven populations and at species level was showed in Table 1.

Fresh leaves from all 11 populations of V.mangachapoi wererandomly collected from 320 individualtrees(DBH≥1.5 cm)(Table 1).To avoid the possibility of sampling from the same mother tree or from the same individual twice,the distance between any two sampled individuals was set at＞30 m(Sist et al.2003).The fresh leaves were collected from the end of July 2006 to August 2007.In all cases,the tissue samples were enclosed in plastic bags under 4°C and immediately transported to the laboratory stored at-70°C before further molecular analysis.

DNA extraction and ISSR-PCR ampli fi cation

The total DNA of leaves was isolated,using the CTAB method protocol(Stewart and Via 1993;Dai et al.2015),and dissolved in 0.5×TE(pH 8.0).After adjusting the concentration,the total DNA was subjected to PCR ampli fi cation(Dai et al.2013)using UBC ISSR Primer(Set No.9,Biotechnology Laboratory,University of British Columbia,Canada).A 20 ng total DNA template was ampli fi ed in a Rapid-cycler(Mastercyclergradient,Eppendorf China Ltd.),with an initial setting of 5 min at 94°C,followed by 32 cycles of 60 s for denaturing at 94 °C,45 s annealing at 50 °C,90 s extension at 72 °C,and ended with 7 min at 72°C.

Reactions were carried out in 20 μL volume containing 1×Reaction Buffer(including 1.5 mM Mg2+);1 U Taq polymerase(Tiangen Biotech,China);0.2 mmol/LdNTPs(Sangon Biotech,China),0.2 μmol/L ISSR primers(synthesized by Sangon Biotech).Ampli fi cation products were analyzed by electrophoresis(1×TBE buffer)at 100 V for 30 min through a 2%agarose gel and stained with ethidium bromide and then imaged using Gel Imaging System(Alpha Imager 2200,Alpha Innotech Corporation).

Vatica mangachapoi,endemic to tropical Asia,has been listed as an ‘A1’endangered tree species on the IUCN red list of threatened species(Ashton 1998),and has also been classi fi ed on the Second-class State Key Protected Wild Plants List in China(State Forestry Administration 1999).Long-lived Dipterocarps are mainly outcrossing,self-incompatible,and winged fruits(Sist et al.2003)and they are both anemochory and insect-pollinated, as is V.mangachapoi.

Statistical analysis

Since ISSR markers are dominant,we assumed that each band represented the phenotype at a single biallellic locus(Matesanz et al.2011).The ampli fi ed fragments of the homologous bands were scored for each individual as present(1)or absent(0)(Matesanz et al.2011;Rucinska and Puchalski 2011).Only the distinct,reproducible and well-resolved fragments were scored.A matrix of ISSR phenotypes for each sample was constructed and analyzed using POPGENE version 1.32 software(Yeh et al.1999).Genetic parameters were estimated as follows:the mean number of alleles(Na),the percentage of polymorphic bands(PPB);the Nei gene diversity test(h)(Nei 1973);and the Shannon information index(I)(Lewontin 1972).The total gene diversity among populations(HT);the gene diversity within populations(HS);(Nei 1972),and the coef fi cient of genetic differentiation among populations within species(GST)(Nei 1973)were included.The value of gene fl ow among populations was calculated in accordance with the following formula:Nm=0.5(1-GST)/GST(McDermott and McDonald 1993).

Analysis of the molecular variance(AMOVA)of the 999 permutations,with the populations nested within disturbance groups(LD,MD,and HD),was conducted Gen-AlEX software,version 6.41(Peakall and Smouse 2006).Then,we examined the distribution of variation among disturbance groups(ΦRT),populations within disturbance groups(ΦPR),and populations(ΦPT)(an analogue of Fst,e.g.genetic diversity among populations)(Breinholt et al.2009).

To examine population structure,we used the standardized covariance method(Fatemi and Gross 2009)in GenAlEX version 6.4.1,with principal coordinates analysis(PCoA)plot based on the pair-wise genetic difference(Binary distance)of population level and individuals level(Dai et al.2013).

地方院校本科生通过参加科研活动，扩大了知识面，感受到较好的学术氛围，对科研工作的目的、意义有了更深层次的理解，独立分析和解决实际问题的能力得到提高。通过参与科研训练，学会掌握现代文献检索工具和手段，增强了获取新的理论知识和了解科学研究动态的本领。

Inter-simple sequence repeat(ISSR)markers are widely used for population genetic studies because they are rapid,ef fi cient,and hyper variable,and can produce massively polymorphic and repeatable loci(Li and Jin 2008;Matesanz et al.2011;Rucinska and Puchalski 2011).Therefore,in the present study we used ISSR markers to evaluate the status of genetic diversity and the genetic differentiation among populations of V.mangachapoi in Hainan Island.

One-way ANOVA was further used to test the in fl uence of disturbance levels on genetic diversity by Tukey’s studentized range(HSD)test,setting p≤0.05 as criterion of statistical signi fi cance.Data analyses were performed using the statistical software SAS version 9.1(SAS Institute Inc.2004).

现如今，形形色色的新颖罐头不断问世，它们包装小巧、方便携带、容易开启，给食用者带来了更多的方便，但是当初人们吃罐头的那种幸福感却越来越少了。

Results

Genetic diversity within populations

To evaluate the status of genetic diversity under different disturbance pressures,the populations were divided into three disturbance levels(Table 1)according to their protection status(being protected or not)and suffering human activities (tourism/villages/roads,hydrological projects,or logging trace):low disturbance(LD),moderate disturbance(MD),and high disturbance(HD)(Please see Supplementary Appendix B ‘Information of all studied populations’).

抽取该院诊治的150例一期肺癌伴发糖尿病患者作为研究对象，纳入标准：①所有患者均自愿参与本次研究并签署知情同意书。②所有患者均意识清楚，神志清晰，精神良好，能配合进行研究。③所有患者均无凝血功能障碍。排除标准：①排除凝血功能障碍患者。②排除意识不清，患有精神疾病的患者。③资料不全者。按随机数字表法分为两组，各75例。对照组：男40例，女35例；年龄范围 58～73 岁，平均（65.41±1.26）岁，观察组：男 41例，女 34例；年龄范围 58～75岁，平均（65.45±1.29）岁。两组患者上述资料差异无统计学意义（P＞0.05）。

Fig.2 Principal coordinates analysis(PCoA)plot(GenAlEx 6.4.1)based on the genetic diversity among the 10 markers used in this study for population identi fi cation

Genetic divergence among populations

The AMOVA of the ISSR data set for the 11 populations revealed most of the variation(76%,p=0.001)resided within the population;2%variation(p=0.001)was among disturbance levels;and 22%variation(p=0.001)was among populations within the disturbance levels.A two-dimensional scatter plot of PCoA analysis revealed three major clusters for population level,which conformed roughly to the geographical distribution of the 11 populations(Fig.2a).Especially,the northernmost population WC1 and the central population TS1 formed a cluster.Axis 1 and axis 2 explained,respectively,35.44 and 25.90% of the variation distribution.

Effects of disturbance on genetic variation

The PCoA analysis for the individual level revealed two clusters:the left one mainly included HD and MD groups,while the right one included LD and MD groups(Fig.2b).The Mantel tests showed that there were strongly positive relations between the pair-wise population geographic isolation and the pair-wise population gene distance(ΦPT)matrix discovered between the 11 populations(p=0.0005;Fig.3).As shown in Table 2,the populations of high disturbance(HD)had greater genetic differentiation(GST),resulting in lower gene fl ow(Nm).Tukey’s multiple comparisontestshowedthatthegeneticvariation(Na,I,andPPB)oflowdisturbance(LD)populationsweregreaterthanthatof the high disturbance(HD)populations(Fig.4;Table 3).

不过艺术家本人表示，其作品与当代诸多问题之间的相似点，可以说只是出于偶然。她试图阻止作品意义变得狭隘，争辩道：“如果政治是开放而非封闭的，艺术家的作品则会适应这种环境。”

Fig.3 The Mantel test for pair-wise population ΦPTgenetic distance matrix and pair-wise populations distance matrices of the geography for 11 populations

Fig.4 Comparison of population genetic diversity for V.mangachapoi among three disturbance levels

Discussion

Genetic diversity of V.mangachapoi populations of V.mangachapoi across Hainan Island.We compared the results of the mean genetic diversity within populations—summarized by Nybom(2004)(mean h for ISSR of long-lived perennial plants,wind dispersal plants,and out-crossing plants were 0.25,0.27,and 0.27,respectively)and compared to other tropical endangered trees,e.g.Hagenia abyssinica(long-lived perennial,outcrossing,anemochory;h=0.30)(Feyissa et al.2007)and we found a relatively low variation within populations of V.mangachapoi(mean h=0.217).However,genetic diversity of V.mangachapoi at species level(h=0.294,I=0.450)was higher than that at the population level,and was also higher than other endangered trees,e.g.Emmenopterys henryi(long-lived perennial,outcrossing,anemochory;h=0.191,I=0.287)(Li and Jin 2008).These results suggest that the genetic variation at species level of V.mangachapoi is relatively high,with a considerable proportion of the genetic variation among populations.

现阶段，我国许多山区水资源都存在短缺的现象，人畜饮水得不到及时的供应，人们只能通过收集雨水来维持生活，如遇干旱少雨的季节，山区井水的水位就会降低，群众的生活用水无法得到保障，农业发展水平与农民的生活水平无法得到提高。水资源短缺的形成原因主要体现在以下两方面[1]，一是山区缺乏健全的供水设施，山区中没有建立调节水池，硬件设备老旧，无法正常运行，导致山区的供水量不足。二是自然环境的恶化造成水资源的短缺，部分人在利益的驱使下，乱砍乱伐森林资源，导致生态平衡被破坏，水土流失现象日益严重。

This study provided a measurement of the genetic diversity present in 320 individual plants among the 11 natural

Table 2 Genetic variation of V.mangachapoi within disturbance level

HT,total gene diversity among populations within disturbance level/species;HS,the gene diversity within populations;GST,the coef fi cient of genetic differentiation among populations within disturbance level/species;Nm,gene fl ow among populations within disturbance level/species

Disturbance level HT HS GST Nm LD 0.288±0.028 0.232±0.018 0.193 2.085 MD 0.276±0.030 0.233±0.021 0.156 2.704 HD 0.255±0.033 0.190±0.019 0.257 1.444 Species level 0.291±0.027 0.272±0.024 0.0637 7.3498

Table 3 Effects of disturbance levels on population genetic diversity of V.mangachapoi

Source Sum of squares Mean square F2,8 P Na 0.075 0.038 8.42 0.011 h 0.004 0.002 3.95 0.064 I 0.010 0.005 4.69 0.045 PPB 0.073 0.037 6.48 0.021

Isolation of population caused genetic reduction and differentiation

Anthropogenic disturbances accelerated and aggravated the fragmentation and shrinkage of remnant populations of V.mangachapoi.Genetic drift may reduce genetic diversity and increase differentiation in smaller and isolated populations(Li and Jin 2008;Gaino et al.2010).The low disturbance(LD)populations of V.mangachapoi possessed higher value for all genetic diversity indices(Fig.4).In comparison,the higher disturbance(HD)populations possessed lower genetic diversity.In addition,the results of PCoA analysis,AMOVA analysis,and Mantel tests strongly con fi rm signi fi cant gene differentiation of populations among different disturbance levels,showing a tendency to get larger.

贵刊 2018年 8月下在《精短杂文小辑》中刊登的署名李羽的《美丽与威慑》，系全文抄袭我的文章（一字未改）。我文首发于《思维与智慧》（2016年第17期），题为《动物小思》（共 18则），先后被《青年文摘》（分 4期）、《特别关注》（分 4期）、《意林》、《经典杂文》等报刊转载。对李羽这种不劳而获、抄袭别人作品的行为应公开谴责！

Therefore,the above results indicate that the anthropogenic disturbances would decrease genetic diversity and cause genetic differentiation among populations of V.mangachapoi,especially highly disturbed populations.Our previous study also found genetic diversity of endangered Madhuca hainanensis was higher in the protected populations with less human disturbance in Hainan(Dai et al.2013).

Due to the long-term isolation derived from anthropogenic forest fragmentation on Hainan(Zhai et al.2014),the outcrossing and self-incompatible mating system of V.mangachapoi may be attributed to the increase of genetic differentiation among remnant populations.This is because anthropogenic disturbances(especially large-scale land transition)will increase geographical isolation of the populations,which can decrease pollen immigration among populations(Bittencourt and Sebbenn 2007)and increase seed dispersal limitation across the fragmented populations(Herrera and Garcia 2010).All of this results in reducing genetic diversity and effective population size(Gaino et al.2010).The following evidence further supports these fi ndings.

A striking genetic divergence with the increasing geographic isolation driven by historical human disturbances is indeed discovered between our populations(Fig.3).The natural forests in Hainan suffered massive anthropogenic disturbance in history(Appendix A:Fig.S1)and werebroken into fragments.The remaining populations of V.mangachapoi were separated from each other spontaneously(Dai et al.2008)and now formed the geographical distribution pattern of isolation(Fig.1).The genetic gap of individuals appeared between low disturbance group and high disturbance group(Fig.2b).

In addition,V.mangachapoi trees begin fructifying after 15 years(Chen 1964).The older mature trees are rarely seen after the historical large-scale deforestation and land conversion.The remnant trees cannot provide effective or suf fi cient gene fl ow.Because of the outcrossing and selfincompatible mating system of V.mangachapoi,the gene fl ow barriers probably occurred,which may result in increasing genetic differentiation among remnant populations by genetic drift(Li and Jin 2008).Therefore,population isolation,which is driven and aggravated by historical human disturbances,might be the cause of signi fi cantgenetic reduction and differentiation ofV.mangachapoi.

Implications for conservation

Current remnant populations have potential to re fl ect historical forest composition and changes.However,the longterm effects of deforestation may be only detected in their progeny,because of time-lag effects between disturbances and expression of traits in plants(Hamrick et al.1992).Even worse,compared with the impact of deforestation on animals,the biological consequence of deforestation on plants are not easily detectable and may not appear in a short-term period,especially at genetic level.Thus,it often may not be obvious enough to attract policymakers’attention.

混凝土切缝时间比较关键，过早、过晚都不行。过早可能会导致混凝土粗料出现脱离情况，过晚则会出现裂缝和断板等问题。在进行切缝作业之前，首先要进行放桩，需要每间隔5m放置一根桩。在进行切缝作业过程中，切割机需要在定向架引导下进行施工作业，以便确保切缝的顺直[4]。

作为教育事业的推动者，任何一个成功的教育举措都饱含着无数教师的积极努力。近些年，随着教师专业化的发展，教师身份研究成为一个独立的研究领域，并日益作为教师专业发展的一个研究视角进入研究者的视线。这一领域的发现，标志着教师研究范式的一大转变，即不再将教师看成是知识、技能的持有者，转而探索教师如何看待自己的角色身份，如何赋予其教育实践以意义，以及如何规划其职业发展，简言之重视个体教师在教学实践中的情感、承诺和勇气等因素。笔者在此对近十年内外教师专业研究做一个简要的文献述评，以期探究其中的研究新展与研究发现，从而寻求对我国教师专业发展的启示。

In addition,tropical deforestation is an expanding global phenomenon(Gaino et al.2010;Zhai et al.2012),resulting in erosion of genetic diversity(Aguilar et al.2008).Although the government has implemented great conservation efforts,recent studies show that tropical plantations,especially rubber and pulp plantation,are still threatening Hainan’s remaining natural tropical forests(Zhai et al.2012,2014)with the reemergence of forest shrinkage on Hainan Island (annual forest density change rate=-0.94%)(Shi et al.2011).

To date,the natural forest in Hainan,even more than 65%nature reserves,is still facing an increasing of fragmentation(Wang et al.2013).Therefore,detailed assessment of these long-term historical disturbances on genetic diversity is extremely important for the urgent conservation management of trees,especially for endangered species(e.g.V.mangachapoi).

We recommend effective conservation pathways to bene fi t to the survival of V.mangachapoi populations on Hainan Island,based on our fi ndings and recommended conservation methods(Schemske et al.1994):

1. In situ conservation is urged as a priority because V.mangachapoi should grow completely free from disturbance,such as slashing in the population DF1 and TS1.

2. The low disturbance populations with higher diversity are the key protected units.

但是我终于出来了。我越过那堆积着像山一样的十八年的长岁月，回到了生我养我而且让我刻印了无数儿时回忆的地方。我走了很多的路。

3. Establishment of corridors,which connected the central population from those key populations of V.mangachapoi,would be an effective strategy to facilitate the gene communication and remove or decrease the in fl uences of geographical isolation.

4. A new reserve should be established for the population WC1,which harbors high genetic diversity and suffers from high geographical isolation and serious anthropogenic activities.

5. Effective restoration of remnant populations with seedlings from populations that possess higher genetic diversity needs to be implemented.

Seeds of V.mangachapoi can keep their vitality within a few days after ripening(Sist et al.2003).There is a clear and urgent need for seeds to be collected and reared to seedling stage,then replanted into the natural populations.

Conclusions

The genetic variation at the species level of V.mangachapoi is relatively high,with a considerable proportion of genetic variation among populations.However,the anthropogenic disturbances decreased genetic diversity and caused genetic differentiation among populations of V.mangachapoi,especially highly disturbed populations.

Acknowledgements We thank all forestry departments in Hainan,China,for their kind cooperation with distribution of surveys and sample collections.We kindly thank Chai-ShianKua(Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,China)for her helpful comments on the early version of this manuscript.We are grateful to the anonymous reviewers and the journal editors for their comments that have helped to improve this manuscript.

Compliance with ethical standards

Con fl ict of interest The authors declare that they have no con fl ict of interest.

References

Aguilar R,Quesada M,Ashworth L,Herrerias-Diego Y,Lobo J(2008)Genetic consequences of habitat fragmentation in plant populations:susceptible signals in plant traits and methodological approaches.Mol Ecol 17:5177–5188

Ashton P(1998)Vatica mangachapoi.IUCN red list of threatened species.Version 2010.2.(http://www.iucnredlist.org/):International Union for Conservation of Nature and Natural Resources(IUCN)

Bittencourt JV,Sebbenn AM(2007)Patterns of pollen and seed dispersal in a small,fragmented population of the windpollinated tree Araucaria angustifolia in southern Brazil.Heredity 99:580–591

Breinholt JW,Van Buren R,Kopp OR,Stephen CL (2009)Population genetic structure of an endangered Utah endemic,Astragalus ampullarioides(Fabaceae).Am J Bot 96:661–667

Bunyavejchewin S,LaFrankie JV,Baker PJ,Kanzaki M,Ashton PS,Yamakura T(2003)Spatial distribution patterns of the dominant canopy dipterocarp species in a seasonal dry evergreen forest in western Thailand.For Ecol Manag 175:87–101

Chen HY(1964)Flora of Hainan,vol 1.Science Press,Beijing,pp 516–517(in Chinese)

Dai ZC,Zhong QX,Si CC,Lin Y,Wang KR,Zhang B,Du DL(2008)A review of study on endangered mechanism and conservation ecology of endangered Vatica mangachapoi.J Hainan Normal University(Natural Science)21:82–86(in Chinese with English abstract)

Dai ZC,Si CC,Zhai DL,Huang P,Qi SS,Zhong QX,Hu X,Li HM,Du DL (2013)Human impacts on genetic diversity and differentiation in six natural populations of Madhuca hainanensis,an endemic and endangered timber species in China.Biochem Syst Ecol 50:212–219

Dai ZC,Qi SS,Miao SL,Liu YT,Tian YF,Zhai DL,Huang P,Du DL(2015)Isolation of NBS-LRR RGAs from invasive Wedelia trilobata and the calculation of evolutionary rates to understand bioinvasion from a molecular evolution perspective.Biochem Syst Ecol 61:19–27

Ding Y,Zang RG,Jiang Y-X(2006)Effect of hillslope gradient on vegetation recovery on abandoned land of shifting cultivation in Hainan Island,South China.J Integr Plant Biol 48:642–653

Fatemi M,Gross CL(2009)Life on the edge—high levels of genetic diversity in a cliff population of Bertya ingramii are attributed to B.rosmarinifolia(Euphorbiaceae).Biol Conserv 142:1461–1468

Feyissa T,Nybom H,Bartish I,Welander M(2007)Analysis of genetic diversity in the endangered tropical tree species Hagenia abyssinica using ISSR markers.Genet Resour Crop Evol 54:947–958

Gaino APSC,Silva AM,Moraes MA,Alves PF,Moraes MLT,Freitas MLM,Sebbenn AM (2010)Understanding the effects of isolation on seed and pollen fl ow,spatial genetic structure and effective population size of the dioecious tropical tree species Myracrodruon urundeuva.Conserv Genet 11:1631–1643

Hamrick JL,Godt MJW,Sherman-Broyles SL(1992)Factors in fl uencing levels of genetic diversity in woody plant species.New For 6:95–124

Herrera JM,Garcia D(2010)Effects of forest fragmentation on seed dispersal and seedling establishment in Ornithochorous trees.Conserv Biol 24:1089–1098

Jump AS,Marchant R,Penuelas J(2009)Environmental change and the option value of genetic diversity.Trends Plant Sci 14:51–58

Lewontin RC(1972)The apportionment of human diversity.Evol Biol 6:381–398

Li JM,Jin ZX(2008)Genetic structure of endangered Emmenopterys henryi Oliv.based on ISSR polymorphism and implications for its conservation.Genetica 133:227–234

Lopez-Pujol J,Zhang FM,Ge S(2006)Plant biodiversity in China:richly varied,endangered,and in need of conservation.Biodivers Conserv 15:3983–4026

Luo S,He Y,Ning G,Zhang J,Ma G,Bao M(2011)Genetic diversity and genetic structure of different populations of the endangered species Davidia involucrata in China detected by inter-simple sequence repeat analysis.Trees Struct Funct 25:1063–1071

Manohara TN,Linto EL,Renuka C(2010)Diversity and conservation of palms in Andaman and Nicobar archipelago.Biodivers Conserv 19:3655–3666

Matesanz S,Gimeno TE,de la Cruz M,Escudero A,Valladares F(2011)Competition may explain the fi ne-scale spatial patterns and genetic structure of two co-occurring plant congeners.J Ecol 99:838–848

Mayer AL,Kauppi PE,Angelstam PK,Zhang Y,Tikka PM(2005)Importing timber, exporting ecological impact. Science 308:359–360

McDermott JM,McDonald BA(1993)Gene fl ow in plant pathosystems.Annu Rev Phytopathol 31:353–373

Nei M(1972)Genetic distance between populations.Am Nat 106:283–292

Nei M(1973)Analysis of gene diversity in subdivided populations.Proc Natl Acad Sci USA 70:3321–3323

Nybom H(2004)Comparison of different nuclear DNA markers for estimating intraspeci fi c genetic diversity in plants.Mol Ecol 13:1143–1155

Peakall ROD,Smouse PE(2006)Genalex 6:genetic analysis in Excel.Population genetic software for teaching and research.Mol Ecol Notes 6:288–295

Rucinska A,Puchalski J(2011)Comparative molecular studies on the genetic diversity of an ex situ garden collection and its source population of the critically endangered polish endemic plant Cochlearia polonica E.Frohlich.Biodivers Conserv 20:401–413

SAS Institute Inc(2004)SAS/STAT user’s guide.Version 9.1.SAS Institute Inc.,Cary

Schemske DW,Husband BC,Ruckelshaus MH,Goodwillie C,Parker IM,Bishop JG(1994)Evaluating approaches to the conservation of care and endangered plants.Ecology 75:584–606

Shi L,Zhao S,Tang Z,Fang J(2011)The changes in china’s forests:an analysis using the forest identity.PLoS ONE 6:e20778

Sist P,Fimbel R,Sheil D,Nasi R,Chevallier MH(2003)Towards sustainable management of mixed dipterocarp forests of Southeast Asia:moving beyond minimum diameter cutting limits.Environ Conserv 30:364–374

State Forestry Administration PR,China(1999)List of National key protected wild plants(1st Part).State Forestry Administration,Beijing(in Chinese)

Stewart CN Jr,Via L(1993)A rapid CTAB DNA isolation technique useful for RAPD fi ngerprinting and other PCR applications.Biotechniques 14:748–750

Wang W,Pechacek P,Zhang M,Xiao N,Zhu J,Li J(2013)Effectiveness of nature reserve system for conserving tropical forests:a statistical evaluation of Hainan Island,China.PLoS ONE 8:e57561

Yeh F,Boyle T,Rongcai Yang,Ye Z,Xian JM(1999)POPGENE 32,Microsoft windows-based freeware for population genetic analysis,version 1.32.University of Alberta,Edmonton

Zhai DL,Cannon CH,Slik JWF,Zhang CP,Dai ZC(2012)Rubber and pulp plantations represent a double threat to Hainan’s natural tropical forests.J Environ Manag 96:64–73

Zhai DL,Xu JC,Dai ZC,Cannon CH,Grumbine RE(2014)Increasing tree cover while losing diverse natural forests in tropical Hainan,China.Reg Environ Change 14:611–621

Zhang YQ,Uusivuori J,Kuuluvainen J(2000)Econometric analysis of the causes of forest land use changes in Hainan,China.Can J For Res 30:1913–1921