濒危植物闽楠幼苗更新及环境解释

为了更好地理解濒危植物闽楠幼苗天然更新与微环境的关系,以广西富川县蚌贝村闽楠天然林胸径5.0 cm以下的更新个体为研究对象。基于0.64 hm₂^{固定监测样地调查数据,采用Pearson相关系数、冗余分析等方法对幼苗更新密度与样地微环境因子关系进行分析。结果表明：(1)闽楠小幼苗更新个体数最多,随龄级增加更新密度呈下降趋势;幼苗向幼树转化率低,小幼苗向中幼苗转化率是闽楠更新成功的关键阶段;(2)闽楠幼苗更新密度与样地灌木层高度、最近母树距离、灌木层覆盖度极显著正相关,与样地光照、草本层覆盖度显著负相关; (3)灌木层高度、最近母树的距离、灌木层覆盖度、叶面积指数、光照、草本层覆盖度、凋落物厚度、土壤盐分是影响闽楠幼苗更新的主要微环境因子,光照和草本层覆盖度是闽楠幼苗更新的限制因子。因此,降低光照强度、减少草本层的覆盖度、增大灌木层的覆盖度等有利于闽楠种群更新发展。}     

Phylogeny and species delimitation of the C‐genome diploid species in Oryza

Abstract The diploid Oryza species with C‐genome type possesses abundant genes useful for rice improvement and provides parental donors of many tetraploid species with the C‐genome (BBCC, CCDD). Despite extensive studies, the phylogenetic relationship among the C‐genome species and the taxonomic status of some taxa remain controversial. In this study, we reconstructed the phylogeny of three diploid species with C‐genome (Oryza officinalis, O. rhizomatis, and O. eichingeri) based on sequences of 68 nuclear single‐copy genes. We obtained a fully resolved phylogenetic tree, clearly indicating the sister relationship of O. officinalis and O. rhizomatis, with O. eichingeri being the more divergent lineage. Incongruent phylogenies of the C‐genome species found in previous studies might result from lineage sorting, introgression/hybridization and limited number of genetic markers used. We further applied a recently developed Bayesian species delimitation method to investigate the species status of the Sri Lankan and African O. eichingeri. Analyses of two datasets (68 genes with a single sample, and 10 genes with multiple samples) support the distinct species status of the Sri Lankan and African O. eichingeri. In addition, we evaluated the impact of the number of sampled individuals and loci on species delimitation. Our simulation suggests that sampling multiple individuals is critically important for species delimitation, particularly for closely related species.     

Investigation on Wild Resource of Valuable Timber Tree Phoebe zhennan (Lauraceae)

Phoebe zhennan is an endemic valuable timber tree to China and was listed as one of the national second class important protected plants. In the study, we investigated the wild resource of Pzhennan, distinguished its confused species and estimated its potential distribution. The results showed that Pzhennan had a sporadic distribution in the areas of Sichuan Basin and Northern Guizhou. Due to deforestation and habitat destruction, Pzhenann mostly shrinked back to fengshui forests with low regeneration, rarely remained in natural forests and some scattered in bamboo forests, few natural regenerating populations were found during our investigation. Two confused species, Lindera megaphylla and Phoebe hui, were distinguished from Pzhennan with the evidence from morphology and DNA barcoding. The results of potential distribution estimation showed that Pzhennan might distribute in Sichuan Basin and Northern Guizhou, but the distribution in Northern Guizhou was fragmentizing. In the future, with global warming, habitat fragmentation of Pzhennan will be intensified and the distribution would tend to move northward with shrinking. Protection countermeasures and suggestions of Pzhennan are discussed.     

复层林对闽楠幼树生长、叶片形态和光合特性的影响

以杉木(Cunninghamia lanceolata (Lamb.) Hook.)、闽楠(Phoebe bournei (Hemsl.) Yang)异龄复层混交林(简称杉楠复层林)和檫木(Sassafras tzumu (Hemsl.) Hemsl.)、闽楠异龄复层混交林(简称檫楠复层林)中的7年生闽楠幼树为研究对象,以纯林中的7年生闽楠幼树为对照,研究3种林分中闽楠幼树的生长量、叶片表型、叶片显微结构、光合色素含量、光合参数日变化和光合-光响应曲线的变化规律,分析复层林和纯林中闽楠幼树生长、叶片形态和光合特性的差异。结果显示：(1)与闽楠纯林相比,杉楠复层林中闽楠幼树的胸径增量和树高增量分别高46.61%和43.87%;檫楠复层林中闽楠幼树的胸径增量和树高增量分别低20.75%和26.53%;(2)与闽楠纯林相比,两种复层林中闽楠幼树的叶片鲜重和含水率减小,叶片变薄变“细长”,同时其中脉厚度、上表皮厚度、下表皮厚度、栅栏组织厚度和海绵组织厚度显著降低;(3)两种复层林中闽楠幼树的叶绿素a、b、总叶绿素和类胡萝卜素含量显著高于纯林中的闽楠;(4)纯林和杉楠复层林中闽楠幼树的净光合速率除上午8∶00外差异不大,檫楠复层林中闽楠的净光合速率在10∶00和14∶00时均显著小于前两者。研究结果表明杉楠复层林下闽楠幼树的生长状况更优,檫楠复层林因为遮阴程度高等原因,对闽楠幼树的生长造成抑制。     

漳河源自然保护区国家重点保护野生植物及保护对策

漳河源自然保护区位于南漳县西南部。在野外调查和文献资料查阅的基础上,对该区国家重点保护野生植物的分布情况进行了研究,结果表明:该区共有国家保护植物21种,其中I级保护植物3种,它们是银杏、红豆杉、南方红豆杉;II级保护植物18种,它们是篦子三尖杉、大果青扦、金荞麦、连香树、野大豆、红豆树、鹅掌楸、厚朴、凹叶厚朴、香果树、榉树、喜树、樟树、闽楠、桢楠、红椿、巴山榧树和黄皮树.分别占湖北省分布的45.65%,37.50%和47.37%。该区的这些国家保护植物具有分布集中、居群规模小、片段化严重、垂直分布明显的特点.并提出了相应的保护对策。     

Woody species in resource‐rich microrefugia of granite outcrops display unique functional signatures

Refugia are key environments in biogeography and conservation. Because of their unique eco‐evolutionary formation and functioning, they should display distinct functional trait signatures. However, comparative trait‐based studies of plants in refugia and non‐refugia are lacking. Here, we provide a comparison between resource‐rich (putative microrefugia for species preferring mesic habitats under increasing aridity) and resource‐impoverished woodlands (non‐refugia) around two granite outcrops in south‐western Australia. We measured and compared six functional traits (bark thickness, foliar δ¹³C, foliar C:N, leaf dry matter content, plant height, specific leaf area) in four woody species. We performed multiple‐trait, multiple‐species and single‐trait, within‐species analyses to test whether plants in resource‐rich habitats were functionally distinct and more diverse than those in the surrounding resource‐impoverished woodlands. We found that species in resource‐rich woodlands occupied larger and distinct multiple‐trait functional spaces and showed distinct single‐trait values (for specific leaf area and bark thickness). This suggests that plants in resource‐rich woodlands can deploy unique and more diverse ecological strategies, potentially making these putative microrefugia more resilient to environmental changes. These findings suggest that species in microrefugia may be characterised by unique functional signatures, illustrating the utility of comparative trait‐based approaches to improve understanding of the functioning of refugia.     

Phylogeny,phylogeography and geographical variation in the Crocidura monax (Soricidae) species complex from the montane islands of Tanzania,with descriptions of three new species

We assess morphological and multilocus genetic variation among 11 isolated montane populations of white‐toothed shrews from Tanzania that have been referred to either Crocidura monax Thomas or C. montis Thomas. The montane sites we sampled represent ‘sky‐islands’ from two geologically distinct archipelagos (Northern Highlands and the Eastern Arc Mountains) and are a significant component of the Eastern Afromontane Biodiversity Hotspot. We used multivariate analyses of morphometric traits and phylogenetic and species‐delimitation analyses of multilocus DNA sequence data to assess species‐level diversity. Our species delimitation analyses included a novel, pairwise validation approach that avoids potential biases associated with specifying a guide tree. These analyses reveal several distinct lineages, which we treat as six allopatric species. Each species is restricted to one, two or four mountains. We use available names to recognize C. monax, C. tansaniana Hutterer and C. usambarae Dippenaar, while naming and describing three new species. Our results demonstrate the effectiveness of combining morphological and genetic data to uncover and describe hidden diversity in a cryptic mammalian system. © 2015 The Linnean Society of London     

闽楠幼树光合特性及生物量分配对光环境的响应

设置100%光环境(L100)、40%光环境(L40)、8%光环境(L8)3种光照梯度,分析万木林闽楠(Phoebe bournei)幼树的光合特性及生物量分配特征对不同光环境的响应。结果表明:(1)闽楠幼树在不同光环境下的最大净光合速率(Pnmax),表观量子效率(AQY),光饱和点(LSP),光补偿点(LCP),暗呼吸速率(Rd)均有显著差异(P<0.05),且随着光照强度的降低,Pnmax,LSP,LCP,Rd随之降低,而AQY却呈现升高的趋势。(2)总生物量、茎生物量、叶生物量、根生物量均表现为L100最大,根冠比、叶生物量比、茎生物量比及根生物量比在3种光环境下无显著差异。(3)闽楠幼树通过改变光合特性,生物量积累来适应光环境的变化,其中光照强度的降低限制了生物量的积累,但并未显著改变生物量地上地下分配比例。闽楠幼树在3种光环境下生物量分配比例并无显著的改变,生物量分配可塑性极低可能是闽楠零散分布的一个重要非人为干扰因素。(4)闽楠幼树所采取的生存策略以地上部分生长为主,光照强度降低时则采取保守策略进行缓慢的资源获取和消耗,全光照条件下采取快速的资源获取和消耗策略。未来造林时可以将闽楠与毛竹(Phyllostachys pubescens)混交来减少郁闭度,促进闽楠幼树的生长。     

人工马尾松林下套种闽楠影响因素研究

采用完全随机区组设计,研究马尾松林下套种闽楠,不同经营模式与林冠层郁闭度调控对闽楠树高、胸径和单株材积影响。结果表明,三种林下套种的复层林经营模式较采伐迹地上造林均可显 著促进闽楠生长。闽楠人工林在1～12龄阶段树高、胸径和单株材积连年生长量及平均生长量均呈逐年上升的趋势,处在生长速生期。采用林下套种闽楠复层林经营模式,并进行林冠层郁闭度调控,长期保持林冠层郁闭度在0.4～0.5左右,可显著促进闽楠生长,是进行闽楠复层林经营的主要关键技术。     

Picking holes in traditional species delimitations: an integrative taxonomic reassessment of the Parmotrema perforatum group (Parmeliaceae,Ascomycota)

Accurate species delimitation is important as species are a fundamental unit in ecological, evolutionary and conservation biology research. In lichenized fungi, species delimitation has been difficult due to a lack of taxonomically important characteristics and due to the limits of traditional, morphology‐based species concepts. In this study we reassess the current taxonomy of the Parmotrema perforatum group, which recognizes six closely related species divided into three species pairs, each pair comprising one apotheciate (sexual) and one sorediate (asexual) species. Each pair is further characterized by a distinct combination of secondary metabolites. It was hypothesized that the three apotheciate species are reproductively isolated sibling species and that each sorediate species evolved once from the chemically identical apotheciate species. In this study, species boundaries were re‐examined using an integrative approach incorporating morphological, chemical and molecular sequence data to delimit species boundaries. Phylogenetic trees were inferred from a seven‐locus DNA sequence dataset using concatenated gene tree and coalescent‐based species‐tree inference methods. Furthermore, we employed a multi‐species coalescent method to validate candidate species. Micromorphological measurements of conidia were found to be congruent with phylogenetic clusters. Each approach that we applied to the P. perforatum group consistently recovered four of the currently circumscribed species (P. perforatum, P. hypotropum, P. subrigidum and P. louisianae), whereas P. preperforatum and P. hypoleucinum were consistently combined and are thus interpreted as conspecific.     

Exploring species boundaries with multiple genetic loci using empirical data from non‐biting midges

Over the past decade, molecular approaches to species delimitation have seen rapid development. However, species delimitation based on a single locus, for example, DNA barcodes, can lead to inaccurate results in cases of recent speciation and incomplete lineage sorting. Here, we compare the performance of Automatic Barcode Gap Discovery (ABGD), Bayesian Poisson tree processes (PTP), networks, generalized mixed Yule coalescent (GMYC) and Bayesian phylogenetics and phylogeography (BPP) models to delineate cryptic species previously detected by DNA barcodes within Tanytarsus (Diptera: Chironomidae) non‐biting midges. We compare the results from analyses of one mitochondrial (cytochrome c oxidase subunit I [COI]) and three nuclear (alanyl‐tRNA synthetase 1 [AATS1], carbamoyl phosphate synthetase 1 [CAD1] and 6‐phosphogluconate dehydrogenase [PGD]) protein‐coding genes. Our results show that species delimitation based on multiple nuclear DNA markers is largely concordant with morphological variation and delimitations using a single locus, for example, the COI barcode. However, ABGD, GMYC, PTP and network models led to conflicting results based on a single locus and delineate species differently than morphology. Results from BPP analyses on multiple loci correspond best with current morphological species concept. In total, 10 lineages of the Tanytarsus curticornis species complex were uncovered. Excluding a Norwegian population of Tanytarsus brundini which might have undergone recent hybridization, this suggests six hitherto unrecognized species new to science. Five distinct species are well supported in the Tanytarsus heusdensis species complex, including two species new to science.     

Large‐sized rare tree species contribute disproportionately to functional diversity in resource acquisition in African tropical forest

Increasing evidence is available for a positive effect of biodiversity on ecosystem productivity and standing biomass, also in highly diverse systems as tropical forests. Biodiversity conservation could therefore be a critical aspect of climate mitigation policies. There is, however, limited understanding of the role of individual species for this relationship, which could aid in focusing conservation efforts and forest management planning. This study characterizes the functional specialization and redundancy for 95% of all tree species (basal area weighted percentage) in a diverse tropical forest in the central Congo Basin and relates this to species' abundance, contribution to aboveground carbon, and maximum size. Functional characterization is based on a set of traits related to resource acquisition (wood density, specific leaf area, leaf carbon, nitrogen and phosphorus content, and leaf stable carbon isotope composition). We show that within both mixed and monodominant tropical forest ecosystems, the highest functional specialization and lowest functional redundancy are solely found in rare tree species and significantly more in rare species holding large‐sized individuals. Rare species cover the entire range of low and high functional redundancy, contributing both unique and redundant functions. Loss of species supporting functional redundancy could be buffered by other species in the community, including more abundant species. This is not the case for species supporting high functional specialization and low functional redundancy, which would need specific conservation attention. In terms of tropical forest management planning, we argue that specific conservation of large‐sized trees is imperative for long‐term maintenance of ecosystem functioning.     

Polyphyly and species delimitation of Picea brachytyla (Pinaceae) based on population genetic data

Accurate species delimitation is fundamental to biodiversity conservation. The endangered spruce Picea brachytyla (Franch.) E. Pritz. was suggested to be polyphyletic based on a limited number of samples in previous studies. To evaluate polyphyly of P. brachytyla, we sampled 139 individuals from 16 populations across most of its distributional range, plus representatives of two related species, Picea likiangensis (Franch.) E. Pritz. and Picea wilsonii Mast. We sequenced 13 nuclear loci and three chloroplast and two mitochondrial loci for the following species delimitation. Phylogenetic analyses of nuclear loci grouped all individuals of P. brachytyla from Sichuan and Chongqing into one distinct lineage and those from Yunnan and Tibet (southern distribution) nested within the P. likiangensis species complex. Structure analyses confirmed this result. Networks of chloroplast DNA haplotypes similarly showed that P. brachytyla from the southern distribution nested within the P. likiangensis species complex, whereas haplotypes for the northern distribution comprised a separate and well-supported lineage. These results suggest that P. brachytyla from the southern distribution is a part of the P. likiangensis species complex and should be removed from P. brachytyla. Our study highlights the utility of population genetic evidence in delimitating endangered species and understanding the conservation status of such species.     

Phylogeny and species delimitation of the C-genome diploid species in Oryza

The diploid Oryza species with C-genome type possesses abundant genes useful for rice improvement and provides parental donors of many tetraploid species with the C-genome (BBCC,CCDD).Despite extensive studies,the phylogenetic relationship among the C-genome species and the taxonomic status of some taxa remain controversial.In this study,we reconstructed the phylogeny of three diploid species with C-genome (Oryza officinalis,O.rhizomatis,and O.eichingeri) based on sequences of 68 nuclear single-copy genes.We obtained a fully resolved phylogenetic tree,clearly indicating the sister relationship of O.officinalis and O.rhizomatis,with O.eichingeri being the more divergent lineage.Incongruent phylogenies of the C-genome species found in previous studies might result from lineage sorting,introgression/hybridization and limited number of genetic markers used.We further applied a recently developed Bayesian species delimitation method to investigate the species status of the Sri Lankan and African O.eichingeri.Analyses of two datasets (68 genes with a single sample,and 10 genes with multiple samples) support the distinct species status of the Sri Lankan and African O.eichingeri.In addition,we evaluated the impact of the number of sampled individuals and loci on species delimitation.Our simulation suggests that sampling multiple individuals is critically important for species delimitation,particularly for closely related species.     

DNA barcoding‐based species delimitation increases species count of Eois (Geometridae) moths in a well‐studied tropical mountain forest by up to 50%

Abstract The genus Eois comprises an important part of megadiverse assemblages of geometrid moths in mountain rainforests of southern Ecuador. In this study we report: (i) on the construction of a DNA barcode library of Eois for identification purposes; and (ii) the exploration of species diversity through species delimitation by pair‐wise distance thresholds. COI barcode sequences were generated from 408 individuals (at least 105 species) collected on a narrow geographic scale (～40 km²) in the Reserva Biológica San Francisco. Analyses of barcode sequence divergence showed that species delimitations based solely on external morphology result in broad overlap of intra‐ and interspecific distances. Species delimitation at a 2% pair‐wise distance threshold reveals a clear barcoding gap. Fifty‐two previously unrecognized species were identified, 31 of which could only be distinguished by an integrative taxonomy approach. Twelve additional putative species could only be recognized by threshold‐based delimitation. Most splits resulted in two or three newly perceived cryptic taxa. The present study increased the number of Eois species recorded from that small area of Andean mountain forest from 102 to 154 (morphology‐ plus integrative taxonomy‐based) or even 166 (sequence‐based), leaving the species accumulation curve still far from reaching an asymptote. Notably, in no case did two or more previously distinguished morphospecies have to be lumped. This barcode inventory can be used to match larvae to known adult samples without rearing, and will therefore be of vital help to extend the currently limited knowledge about food plant relationships and host specialization.     

Trait‐abundance relation in response to nutrient addition in a Tibetan alpine meadow: The importance of species trade‐off in resource conservation and acquisition

In competition‐dominated communities, traits promoting resource conservation and competitive ability are expected to have an important influence on species relative abundance (SRA). Yet, few studies have tested the trait‐abundance relations in the line of species trade‐off in resource conservation versus acquisition, indicating by multiple traits coordination. We measured SRA and key functional traits involving leaf economic spectrum (SLA, specific leaf area; LDMC, leaf dry matter content; LCC, leaf carbon concentration; LNC, leaf nitrogen concentration; LPC, leaf phosphorus concentration; Hs, mature height) for ten common species in all plots subjected to addition of nitrogen fertilizer (N), phosphorus fertilizer (P), or both of them (NP) in a Tibetan alpine meadow. We test whether SRA is positively related with traits promoting plant resource conservation, while negatively correlated with traits promoting plant growth and resource acquisition. We found that species were primarily differentiated along a trade‐off axis involving traits promoting nutrient acquisition and fast growth (e.g., LPC and SLA) versus traits promoting resource conservation and competition ability (e.g., large LDMC). We further found that SRA was positively correlated with plant height, LDMC, and LCC, but negatively associated with SLA and leaf nutrient concentration irrespective of fertilization. A stronger positive height‐SRA was found in NP‐fertilized plots than in other plots, while negative correlations between SRA and SLA and LPC were found in N or P fertilized plots. The results indicate that species trade‐off in nutrient acquisition and resource conservation was a key driver of SRA in competition‐dominated communities following fertilization, with the linkage between SRA and traits depending on plant competition for specific soil nutrient and/or light availability. The results highlight the importance of competitive exclusion in plant community assembly following fertilization and suggest that abundant species in local communities become dominated at expense of growth while infrequent species hold an advantage in fast growth and dispersals to neighbor meta‐communities.     

Delimiting cryptic pathogen species causing apple Valsa canker with multilocus data

Fungal diseases are posing tremendous threats to global economy and food safety. Among them, Valsa canker, caused by fungi of Valsa and their Cytospora anamorphs, has been a serious threat to fruit and forest trees and is one of the most destructive diseases of apple in East Asia, particularly. Accurate and robust delimitation of pathogen species is not only essential for the development of effective disease control programs, but also will advance our understanding of the emergence of plant diseases. However, species delimitation is especially difficult in Valsa because of the high variability of morphological traits and in many cases the lack of the teleomorph. In this study, we delimitated species boundary for pathogens causing apple Valsa canker with a multifaceted approach. Based on three independent loci, the internal transcribed spacer (ITS), β‐tubulin (Btu), and translation elongation factor‐1 alpha (EF1α), we inferred gene trees with both maximum likelihood and Bayesian methods, estimated species tree with Bayesian multispecies coalescent approaches, and validated species tree with Bayesian species delimitation. Through divergence time estimation and ancestral host reconstruction, we tested the possible underlying mechanisms for fungal speciation and host‐range change. Our results proved that two varieties of the former morphological species V. mali represented two distinct species, V. mali and V. pyri, which diverged about 5 million years ago, much later than the divergence of their preferred hosts, excluding a scenario of fungi–host co‐speciation. The marked different thermal preferences and contrasting pathogenicity in cross‐inoculation suggest ecological divergences between the two species. Apple was the most likely ancestral host for both V. mali and V. pyri. Host‐range expansion led to the occurrence of V. pyri on both pear and apple. Our results also represent an example in which ITS data might underestimate species diversity.     

Mapping tree species in temperate deciduous woodland using time‐series multi‐spectral data

Questions: What is the optimum combination of image dates across a growing season for tree species differentiation in multi‐spectral data and how does species composition affect overstorey canopy density? Location: Monks Wood, Cambridgeshire, eastern England, UK. Methods: Six overstorey tree species were mapped using five Airborne Thematic Mapper images acquired across the 2003 growing season (17 March, 30 May, 16 July, 23 September, 27 October). After image pre‐processing, supervised maximum likelihood classification was performed on the images and on all two‐, three‐, four‐ and five‐date combinations. Relationships between tree species composition and canopy density were assessed using regression analyses. Results: The image with the greatest tree species discrimination was acquired on 27/10 when the overstorey species were in different stages of leaf tinting and fall. In this image, tree species were mapped with an overall classification accuracy (OCA) of 71% (kappa 0.63). A similar OCA was achieved from the other four images combined (OCA 72%, kappa 0.64). The highest classification accuracy was achieved by combining three images: 17 March, 16 July, 27 October. This achieved an OCA of 84% (kappa 0.79), increasing to 88% (kappa 0.85) after a post‐classification clump and sieve procedure. Canopy height and percentage cover of oak explained 72% of variance in canopy density. Conclusions: The ability to discriminate and map temperate deciduous tree species in airborne multi‐spectral imagery is increased using time‐series data. An autumn image supplemented with an image from both the green‐up and full‐leaf phases was optimum. The derived tree species map provides a more powerful ecological tool for determining woodland structural/compositional relationships than field‐based measures.     

Cryptic diversity and discordance in single‐locus species delimitation methods within horned lizards (Phrynosomatidae: Phrynosoma)

Biodiversity reduction and loss continues to progress at an alarming rate, and thus, there is widespread interest in utilizing rapid and efficient methods for quantifying and delimiting taxonomic diversity. Single‐locus species delimitation methods have become popular, in part due to the adoption of the DNA barcoding paradigm. These techniques can be broadly classified into tree‐based and distance‐based methods depending on whether species are delimited based on a constructed genealogy. Although the relative performance of these methods has been tested repeatedly with simulations, additional studies are needed to assess congruence with empirical data. We compiled a large data set of mitochondrial ND4 sequences from horned lizards (Phrynosoma) to elucidate congruence using four tree‐based (single‐threshold GMYC, multiple‐threshold GMYC, bPTP, mPTP) and one distance‐based (ABGD) species delimitation models. We were particularly interested in cases with highly uneven sampling and/or large differences in intraspecific diversity. Results showed a high degree of discordance among methods, with multiple‐threshold GMYC and bPTP suggesting an unrealistically high number of species (29 and 26 species within the P. douglasii complex alone). The single‐threshold GMYC model was the most conservative, likely a result of difficulty in locating the inflection point in the genealogies. mPTP and ABGD appeared to be the most stable across sampling regimes and suggested the presence of additional cryptic species that warrant further investigation. These results suggest that the mPTP model may be preferable in empirical data sets with highly uneven sampling or large differences in effective population sizes of species.