Woody Plant Families Research Articles

Chromosome-level genome assembly of the Australian rainforest tree Rhodamnia argentea (malletwood).

Myrtaceae are a large family of woody plants, including hundreds that are currently under threat from the global spread of a fungal pathogen, Austropuccinia psidii (G.Winter) Beenken, which causes myrtle rust. A reference genome for the Australian native rainforest tree Rhodamnia argentea Benth. (malletwood) was assembled from Oxford Nanopore Technologies (ONT) long-reads, 10x Genomics Chromium linked-reads, and Hi-C data (N50 = 32.3 Mbp and BUSCO completeness 98.0%) with 99.0% of the 347 Mbp assembly anchored to 11 chromosomes (2n = 22). The R. argentea genome will inform conservation efforts for Myrtaceae species threatened by myrtle rust, against which it shows variable resistance. We observed contamination in the sequencing data and further investigation revealed an arthropod source. This study emphasises the importance of checking sequencing data for contamination, especially when working with non-model organisms. It also enhances our understanding of a tree that faces conservation challenges, contributing to broader biodiversity initiatives.

Reevaluation of pollen differentiation in Altingiaceae: Challenges in distinguishing deciduous (Liquidambar) and evergreen (Altingia) types using multivariate statistics and machine learning

Altingiaceae, a family of woody plants, comprising evergreen Altingia and deciduous Liquidambar groups, exhibits distinct leaf morphology, yet both groups overlap in geographical range and climatic conditions. While some tropical Altingia species are confined to Myanmar, Thailand, Cambodia and India without Liquidambar, and some temperate Liquidambar species to northern China without Altingia. Their fossil pollen have significant implications in reconstructing palaeoclimate and historical biogeography, based on classification of Altingia-type and Liquidambar-type. However, the results of previous studies to differentiate pollen types of evergreen Altingia and deciduous Liquidambar were based on limited pollen specimens. Therefore pollen morphology of Altingiaceae and differentiation of above mentioned types needs reevaluation using more specimens from wider geographical range.In this study, we present new findings on Altingiaceae pollen morphology from extensive collection of specimens and reassess the diagnostic features to distinguish evergreen and deciduous types. To improve the credibility of palaeoecological and palaeoclimatic interpretations, we applied multivariate statistical analyses to pollen size, number of pores, pollen wall thickness, and size and density of ornamental elements from light microscopy (LM) and Scanning Electronic Microscope (SEM) images. Additionally, random forest classification models were applied to test the accuracy of differentiating Altingiaceae pollen types. Our results reveal significant morphological overlap between the pollen of evergreen Altingia and deciduous Liquidambar, with classification models showing limited accuracy and explainability. Thus, fossil pollen of Altingiaceae cannot be confidently classified into evergreen or deciduous types, highlighting challenges in using their pollen morphology for taxonomic classification in palaeoecological research.

Prospecting for non-timber forest products by chemical analysis of four species of Lauraceae from the Amazon region of Colombia

Lauraceae is a family of woody plants of economic importance mainly for their commercial exploitation as timber, as well as spices/food. Nonetheless, overexploitation is causing a decline in both the population and the associated ecosystems due to the lack of sustainability strategies and knowledge of alternative ways of utilization. The focus of this research was to determine if the secondary metabolites found/identified in the volatile fractions/ethyl acetate extracts of Aniba panurensis, Nectandra cuspidata, Ocotea cymbarum and O. myriantha from the Amazon region of Colombia (Departamento de Caquetá) would be promising/interesting for industry, so that uses/exploitation other than timber could be recommended. In this work, the chemical compositions by GC–FID/MS of the volatile fractions/total extracts (by HS–SPME/SDE/maceration) of the trunk wood of these trees were determined. The results were: (i) the volatile fractions/extracts of A. panurensis were composed of 88–94% benzenoid-type aromatic esters (benzyl salicylate and benzoate); (ii) N. cuspidata contained 95% sesquiterpenes (α-copaene and α-cubebene/germacrene D) by HS–SPME, 89% oxygenated and hydrocarbonated sesquiterpenes (τ-cadinol and δ-cadinene) by SDE, and 87% sesquiterpenes and aporphine alkaloids (α-copaene/germacrene D/δ-cadinene/α-cubebene and dicentrine/dehydrodicentrine) by solvent extraction; (iii) O. cymbarum contained mainly 63% sesquiterpenes and monoterpene ethers (α-copaene/trans-calamenene and eucalyptol) by HS–SPME, 63–85% of monoterpene alcohols (α-terpineol/borneol)/hydrocarbons (α-/β-pinenes)/ethers (eucalyptol) and phenylpropanoid ethers (methyleugenol) by SDE/solvent extraction; and (iv) for O. myriantha, the constituents per family were 91% sesquiterpenes (bicyclogermacrene/germacrene D)—HS–SPME, 72% sesquiterpene alcohols and sesquiterpenes/monoterpenes (spathulenol and bicyclogermacrene/δ-3-carene)—SDE, and 69% benzenoid-type aromatic esters and sesquiterpene hydrocarbons/alcohols (benzyl salicylate and bicyclogermacrene/α-cadinol)—solvent extraction. In conclusion, the main constituents identified in the woods (volatile fractions/extracts) of the species could be isolated and sustainably used/exploitated due to their bioproperties, as well as for their fragrant properties, some of which could be harnessed by different sectors/types of industries.

Phylogenetics and biogeography of the olive family (Oleaceae).

Progress in the systematic studies of the olive family (Oleaceae) during the last two decades provides the opportunity to update its backbone phylogeny and to investigate its historical biogeography. We additionally aimed to understand the factors underlying the disjunct distribution pattern between East Asia and both West Asia and Europe that is found more commonly in this family than in any other woody plant families. Using a sampling of 298 species out of ca. 750, the largest in a phylogenetic study of Oleaceae thus far, and a set of 36 plastid and nuclear markers, we reconstructed and dated a new phylogenetic tree based on maximum likelihood and Bayesian methods and checked for any reticulation events. We also assessed the relative support of four competing hypotheses [Qinghai-Tibet Plateau uplift (QTP-only hypothesis), climatic fluctuations (Climate-only hypothesis), combined effects of QTP uplift and climate (QTP-Climate hypothesis), and no effects (Null hypothesis)] in explaining these disjunct distributions. We recovered all tribes and subtribes within Oleaceae as monophyletic, but uncertainty in the position of tribe Forsythieae remains. Based on this dataset, no reticulation event was detected. Our biogeographic analyses support the QTP-Climate hypothesis as the likely main explanation for the East-West Eurasian disjunctions in Oleaceae. Our results also show an earlier origin of Oleaceae at ca. 86 Mya and the role of Tropical Asia as a main source of species dispersals. Our new family-wide and extensive phylogenetic tree highlights both the stable relationships within Oleaceae, including the polyphyly of the genus Chionanthus, and the need for further systematic studies within the family's largest and most under-sampled genera (Chionanthus and Jasminum). Increased sampling will also help to fine-tune biogeographic analyses across spatial scales and geological times.

Differential effects of tree species identity on rhizospheric bacterial and fungal community richness and composition across multiple trace element-contaminated sites

Soil microbial communities play a key role in plant nutrition and stress tolerance. This is particularly true in sites contaminated by trace metals, which often have low fertility and stressful conditions for woody plants in particular. However, we have limited knowledge of the abiotic and biotic factors affecting the richness and composition of microbial communities inhabiting the rhizosphere of plants in contaminated sites. Using high-throughput amplicon sequencing, we studied the rhizospheric bacterial and fungal community structures of 14 woody plant families planted in three contrasting sites contaminated by metals (Pb, Cd, Zn, Mn, Fe, S). The rhizospheric bacterial communities in the given sites showed no significant difference between the various woody species but did differ significantly between sites. The Proteobacteria phylum was dominant, accounting for over 25 % of the overall relative abundance, followed by Actinobacteria, Bacteroidetes and Gemmatimonadetes. Site was also the main driver of fungal community composition, yet unlike bacteria, tree species identity significantly affected fungal communities. The Betulaceae, Salicaceae and Fagaceae families had a high proportion of Basidiomycota, particularly ectomycorrhizal fungi, and the lowest diversity and richness. The other tree families and the unplanted soil harboured a greater abundance of Ascomycota and Mucoromycota. Consequently, for both bacteria and fungi, the site effect significantly impacted their community richness and composition, while the influence of plants on the richness and composition of rhizospheric microbial communities stayed consistent across sites and was dependent on the microbial kingdom. Finally, we highlighted the importance of considering this contrasting response of plant rhizospheric microbial communities in relation to their host identity, particularly to improve assisted revegetation efforts at contaminated sites.

Identifying Fagaceae and Lauraceae species using leaf images and convolutional neural networks

Lauraceae and Fagaceae are two large woody plant families that are predominant in the low- and middle-altitude regions in Taiwan. The highly interspecific similarity between some species of the family brings limitations on the management and utilization. This work proposed an approach for identifying 15 Lauraceae species and 20 Fagaceae species using leaf images and convolutional neural networks (CNNs). Leaf specimens of 35 species were collected from the northern, central, and southern parts of Taiwan. Images of the leaves were acquired using flat-bed scanners. Three CNN architectures—DenseNet-121, MobileNet V2, and Xception—were trained. Xception achieved the highest mean test accuracy of 99.39%, and MobileNet V2 required the shortest mean test time of 17.1 ms per image using a GPU. The saliency maps revealed that the characteristics learned by models matched the leaf features used by botanists. A pruning algorithm, gate decorator, was applied to the trained models for reducing the number of parameters and number of floating-point operations of the MobileNet V2 by 55.4% and 69.1%, respectively, while the model accuracy was maintained at 92.03%. Thus, MobileNet V2 has the potential to be used for identifying the Lauraceae and Fagaceae species on mobile devices.

Fossil-Informed Models Reveal a Boreotropical Origin and Divergent Evolutionary Trajectories in the Walnut Family (Juglandaceae).

Temperate woody plants in the Northern Hemisphere have long been known to exhibit high species richness in East Asia and North America and significantly lower diversity in Europe, but the causes of this pattern remain debated. Here, we quantify the roles of dispersal, niche evolution, and extinction in shaping the geographic diversity of the temperate woody plant family Juglandaceae (walnuts and their relatives). Integrating evidence from molecular, morphological, fossil, and (paleo)environmental data, we find strong support for a Boreotropical origin of the family with contrasting evolutionary trajectories between the temperate subfamily Juglandoideae and the tropical subfamily Engelhardioideae. Juglandoideae rapidly evolved frost tolerance when the global climate shifted to ice-house conditions from the Oligocene, with diversification at high latitudes especially in Europe and Asia during the Miocene. Subsequent range contraction at high latitudes and high levels of extinction in Europe driven by global cooling led to the current regional disparity in species diversity. Engelhardioideae showed temperature conservatism while adapting to increased humidity, tracking tropical climates to low latitudes since the middle Eocene with comparatively little diversification, perhaps due to high competition in the tropical zone. The biogeographic history of Juglandaceae shows that the North Atlantic land bridge and Europe played more critical roles than previously thought in linking the floras of East Asia and North America, and showcases the complex interplay among climate change, niche evolution, dispersal, and extinction that shaped the modern disjunct pattern of species richness in temperate woody plants. [Boreotropical origin; climatic niche evolution; disjunct distribution; dispersal; diversity anomaly; extinction; Juglandaceae.]

Research Progress in Plant Molecular Systematics of Lauraceae.

Simple SummaryLauraceae, as an angiosperm group with high ecological and economic value, has been widely studied. With the development of science and technology, the research of Lauraceae has changed from morphology to molecular systematics. Our paper reviewed the molecular phylogeny of Lauraceae in recent years. From the aspects of gene fragments, chloroplast genome and DNA barcodes, we mainly discussed the establishment of Cinnamomeae in the ‘Core Lauraceae’ and the tribal controversial genera (Actinodaphne, Sassafras, Caryodaphnopsis, Neocinnamomum and Cassytha). We think that the whole genome and inflorescence characteristics are the breakthrough to solve the tribal problem of Lauraceae. Using reliable molecular and morphological evidence to reconstruct the phylogenetic relationship of Lauraceae will provide an important theoretical basis for the rational utilization of Lauraceae resources, the development of potential resources and the protection of rare plants.Lauraceae is a large family of woody plants with high ecological and economic value. The tribal and generic division and phylogenetic relationship of Lauraceae have long been controversial. Based on morphological and molecular evidence, phylogenetic relationships within the Cinnamomeae, Laureae and Perseeae tribes, also called ‘the Core Lauraceae’, have arisen particular attention. In this review, we comprehensively collated the literatures on the phylogeny of Lauraceae published in recent years and summarized progress made in molecular systematic researches employing gene fragments, chloroplast genomes and DNA barcodings analyses. We clarified the phylogenetic relationships and main controversies of ‘the Core Lauraceae’, the systemic position of fuzzy genera (Neocinnamomum, Caryodaphnopsis and Cassytha) and the development of chloroplast genome and DNA barcodes. We further suggested and proposed the whole genome analysis and different inflorescence types would be possible to provide more information for further research on phylogenetic relationships and taxonomy of Lauraceae.

Chloroplast genome assembly of Handroanthus impetiginosus: comparative analysis and molecular evolution in Bignoniaceae.

Bignoniaceae species have conserved chloroplast structure, with hotspots of nucleotide diversity. Several genes are under positive selection, and can be targets for evolutionary studies. Bignoniaceae is one of the most species-rich family of woody plants in Neotropical seasonally dry forests. Here we report the assembly of Handroanthus impetiginosus chloroplast genome and evolutionary comparative analyses of ten Bignoniaceae species representing the genera for which whole-genome chloroplast sequences were available. The chloroplast genome of H. impetiginosus is 159,462bp in size and has a similar structure compared to the other nine species. The total number of genes was slightly variable amongst the Bignoniaceae, ranging from 124 in H. impetiginosus to 144 in Anemopaegma acutifolium. The inverted repeat (IR) size was variable, ranging from 24,657bp (Tecomaria capensis) to 40,481bp (A. acutifolium), due to the contraction and retraction at its boundaries. However, gene boundaries were very similar among the ten species. We found 98 forward and palindromic dispersed repeats, and 85 simple sequence repeats (SSRs). In general, chloroplast sequences were highly conserved, with few nucleotide diversity hotspots in the genes accD, clpP, rpoA, ycf1, ycf2. The phylogenetic analysis based on 77 coding genes was highly consistent with Angiosperm Phylogeny Group (APG) IV. Our results also indicate that most genes are under negative selection or neutral evolution. We found no evidence of branch-site selection, implying that H. impetiginosus is not evolving faster than the other species analyzed, notwithstanding we found site positive selection signal in several genes. These genes can provide targets for evolutionary studies in Bignoniaceae and Lamiales species.

Identifying Fagaceae Species in Taiwan Using Leaf Images

Abstract. Fagaceae is the second-largest woody plant family in Taiwan and has considerable economic and ecological value. Identifying Fagaceae species is essential for forest managers and forestry technical personnel. In this study, ten Fagaceae species were distinguished using image processing and machine learning. For each species, 100 leaf images were collected using flatbed scanners. The morphological, marginal, color, and textural traits of the leaves were then quantified. A genetic algorithm was next applied to identify the traits that are essential for species identification. Support vector machine classifiers were developed to identify the species using the selected traits as the inputs. The results indicated that the proposed approach had an accuracy of 92.8%. Keywords: Fagaceae, Image processing, Machine learning, Species identification, Trait selection.

Determinants of Termite Assemblages' Characteristics within Natural Habitats of a Sudano-Guinean Savanna (Comoe National Park, Côte d'Ivoire).

Termites are one of the major components of tropical ecosystems. However, the ecological and biological variables determining the structure of their communities within natural habitats are less documented in general and especially in the Comoe National Park, a Sudano-Guinean savanna zone located in the north-eastern part of Côte d’Ivoire (West Africa). Using a standardized method of belt transects, the structure of termite’s communities was estimated within habitats differing in the structure of their vegetation, soil characteristics, and the disturbance level caused by annual occurrences of bushfires. The effect of a set of environmental variables (habitat type, occurrence of annual bushfire, woody plant density, woody plant species richness, and soil physicochemical parameters) was tested on the habitat-specific recorded termite species. Sixty species of termites belonging to 19 genera, seven subfamilies and two families, namely Rhinotermitidae (Coptotermitinae and Rhinotermitinae) and Termitidae (Apicotermitinae, Cubitermitinae, Macrotermitinae, Nasutitermitinae, and Termitinae) were sampled. These species were assigned to the four feeding groups of termites: fungus growers (18 species), wood feeders (17 species), soil feeders (19 species) and the grass feeders (6 species). The highest diversity of termites was encountered in forest habitats, with 37 and 34, respectively, for the gallery forest and the forest island. Among savanna habitats, the woodland savanna was identified as the most diversified habitat with 32 recorded species, followed by the tree savanna (28 species) and the grassy savanna (17 species). The distribution of termite species and their respective feedings groups was determined by the habitat type and a set of environmental variables such as Woody Plant Diversity (WPD), Woody plant Families Diversity (WPFD), and Organic Carbon (OC). The annual Fire Occurrence (FO) was found to indirectly impact the characteristics of termite assemblages within natural habitats via their respective Herbaceous Species Richness (HSR) and Woody Plant Species Richness (WPSR). In summary, the spatial heterogeneity of the Comoe National Park, modeled by the uncontrolled annual bushfire, offers a diversified natural habitat with an important variety of termite-habitat-specific species, probably due to the food preference of these organisms and its relatively good conservation status.

Plant Systematics World

TAXONVolume 67, Issue 5 p. 1053-1054 TypificationsFree Access Plant Systematics World Vicki Funk, Vicki Funk funkv@si.edu Search for more papers by this author Vicki Funk, Vicki Funk funkv@si.edu Search for more papers by this author First published: 01 October 2018 https://doi.org/10.12705/675.28AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Gaiser, L.O. 1921. Cell division in the pollen mother cell of Anthurium. Masters thesis, Columbia University, New York, U.S.A. Gaiser, L.O. 1924. Intracellular relations of aggregate crystals in the spadix of Anthurium. Bull. Torrey Bot. Club 50: 389– 398. https://doi.org/10.2307/2479927 Gaiser, L.O. 1926. A list of chromosome numbers in Angiosperms [I]. Genetica 8: 401– 484. Gaiser, L.O. 1927. Chromosome numbers and species characters in Anthurium. Trans. Roy. Soc. Canada, Sect. 5, Biol. Sci., ser. 3, 21: 1– 134. Gaiser, L.O. 1930. Chromosome numbers in Angiosperms II. Bibliogr. Genet. 6: 171– 466. https://archive.org/details/in.ernet.dli.2015.270967 Gaiser, L.O. 1930. Chromosome numbers in Angiosperms II I. Genetica 12: 161– 260. https://archive.org/details/in.ernet.dli.2015.270965 Gaiser, L.O. 1933. A list of chromosome numbers in Angiosperms IV. Bibliogr. Genet. 10: 105– 250. https://archive.org/details/in.ernet.dli.2015.270966 Gaiser, L.O., Sutherland, M. & Moore, R. 1943. Cytological studies in Martynia louisiana. Amer. J. Bot. 30: 543– 551. https://doi.org/10.1002/j.1537-2197.1943.tb14797.x Gaiser, L.O. 1946. The genus Liatris. Rhodora 48: 165– 183, 216–263, 273–326, 331–382, 393–412. Gaiser, L.O. 1949. Further distribution of Butomus umbellatus in the Great Lakes region. Rhodora 51: 385– 390. Gaiser, L.O. 1949. Chromosome studies in Liatris I. Spicatae and Pycnostachyae. Amer. J. Bot. 36: 122– 135. https://doi.org/10.1002/j.1537-2197.1949.tb05238.x Gaiser, L.O. 1950. Chromosome studies in Liatris II. Graminifoliae and Pauciflorae. Amer. J. Bot. 37: 414– 223. https://doi.org/10.1002/j.1537-2197.1950.tb08191.x Gaiser, L.O. 1950. Chromosome studies in Liatris III. Punctatae. Amer. J. Bot. 37: 763– 777. https://doi.org/10.1002/j.1537-2197.1950.tb11069.x Gaiser, L.O. 1950. Asynapsis and triploidy in a population of Liatris ligulistylis. Lloydia 13: 229– 242. Gaiser, L.O. 1951. Evidence for intersectional field hybrids in Liatris. Evolution 5: 52– 67. https://doi.org/10.1111/j.1558-5646.1951.tb02759.x Gaiser, L.O. 1951. Evidence for the hybrid nature of X Liatris creditonensis. Madroño 11: 10– 22. Gaiser, L.O. 1951. A natural hybrid of Liatris (X L. weaveri Shinners). Amer. Midl. Naturalist 45: 750– 763. https://doi.org/10.2307/2422003 Gaiser, L.O. 1951. Chromosome studies in Liatris IV. Scariosae, Tenuifoliae, Elegantes, and Cylindraceae. [Gaiser listed this paper in the literature cited section of a publication as “in prep.” but it was apparently never published.] Gaiser, L.O. 1952. Some rarely collected Mexican Brickellias. Rhodora 54: 229– 232. Gaiser, L.O. 1953. Chromosome studies in Kuhniinae (Eupatorieae). I. Brickellia. Rhodora 55: 253– 267, 269–288, 297–321, 328–345. Gaiser, L.O. 1954. Studies in the Kuhniinae (Eupatorieae) II. J. Arnold Arbor. 35: 87– 133. Zavitz, C.H. & Gaiser L.O. 1956. Notes on Triphora trianthophora in Ontario. Rhodora 58: 31– 35. Gaiser, L.O. & Moore, RJ. 1966. A survey of the vascular plants of Lambton County, Ontario. Ottawa: Plant Research Institute, Research Branch, Canada Department of Agriculture. [Supposed to be on line at: http://agris.fao.org but I could not find it.] Volume67, Issue5October 2018Pages 1053-1054 ReferencesRelatedInformation

Do genetic diversity patterns of soil ammonia-oxidizing microorganisms (AOM) match the habitat types of the NATURA2000 scheme?

Despite the important role of soil ammonia-oxidizing microorganisms (AOM) in the biogeochemical cycle of nitrogen, a unified view of the factors driving their spatial pattern of abundance and genetic diversity in terrestrial ecosystems is still lacking. The objective of this study was to explore whether abundance and genetic diversity of AOM follow the existing diversity of habitat types of the NATURA2000. We evaluated the relative abundance of ammonia-oxidizing bacteria (AOB) and archaea (AOA), as well as their genetic diversity in pastoral landscapes of an eastern Mediterranean island. Focusing on six different NATURA2000 habitat types of Crete, the study of AOM was based on culture-independent techniques, while vegetation and soil data of each habitat type were also collected and incorporated in the analysis. Our results suggest that the relative abundances of soil AOB and AOA in the pastoral landscapes of Crete are related to a limited number of soil factors, while their genetic diversity patterns are mainly explained by the dominant woody plant families, and partially by the soil parameters, but do not match the habitat types of the NATURA2000 scheme. The variation of genetic diversity of soil AOM is not predicted from the habitat types of the NATURA2000 scheme. Thus, NATURA2000 habitat types cannot serve as a management scheme of soil AOM.

Impacts of a mineral lick-centred land use system on woody vegetation cover in an East African Savannah

Evaluation of woody vegetation changes with distance from a salt crater was conducted in the semi‐arid rangelands of southern Ethiopia. Data on live woody plants were collected over three seasons at 0, 1, 4, 6, 9 and 12 km from the salt crater. The density and diversity of woody plants differed significantly (p < .01) along the distance gradient. Six woody plant families were identified of which Fabaceae and Burseraceae were the dominant families. Acacia drepanolobium, Acacia nilotica, Commiphora africana and Acacia mellifera were among the severely encroaching woody species. There were high proportions of seedlings and saplings recorded closer to the salt crater showing a vigorous recruitment by woody plants. Woody plant encroachment along the 12‐km transect ranged from a low to severe encroachment, which could be translated into poor rangeland condition. Changes in soil characteristics increased grazing pressure and sedentary settlement around the salt crater, and the breakdown of traditional institutions seems to be major contributing factors to these vegetation changes. We suggest that severely encroached areas could be improved through a combination of methods such as bush clearing, prescribed fire, browsing animals and proper grazing management.

О различиях результатов флорогеографического районирования Cеверной Евразии по видам, родам и семействам древесных растений

О различиях результатов флорогеографического районирования Cеверной Евразии по видам, родам и семействам древесных растений

Patterns and determinants of plant biodiversity in non-commercial forests of eastern China.

Non-commercial forests represent important habitats for the maintenance of biodiversity and ecosystem function in China, yet no studies have explored the patterns and determinants of plant biodiversity in these human dominated landscapes. Here we test the influence of (1) forest type (pine, mixed, and broad-leaved), (2) disturbance history, and (3) environmental factors, on tree species richness and composition in 600 study plots in eastern China. In total, we found 143 species in 53 families of woody plants, with a number of species rare and endemic in the study region. Species richness in mixed forest and broad-leaved forest was higher than that in pine forest, and was higher in forests with less disturbance. Species composition was influenced by environment factors in different ways in different forest types, with important variables including elevation, soil depth and aspect. Surprisingly, we found little effect of forest age after disturbance on species composition. Most non-commercial forests in this region are dominated by species poor pine forests and mixed young forests. As such, our results highlight the importance of broad-leaved forests for regional plant biodiversity conservation. To increase the representation of broad-leaved non-commercial forests, specific management practices such as thinning of pine trees could be undertaken.

Ferric reduction oxidase 2 gene from Pyrus betulifolia is regulated by iron deficiency and auxin

Pyrus betulifolia Bunge belongs to the woody plant family and is an ideal model for studying molecular strategies of iron acquisition and metabolism in strategy I plants. Using polymerase chain rea...

Agrobacterium-Mediated Stable Genetic Transformation of Populus angustifolia and Populus balsamifera.

The present study demonstrates Agrobacterium tumefaciens-mediated stable genetic transformation of two species of poplar – Populus angustifolia and Populus balsamifera. The binary vector pCAMBIA-Npro-long-Luc containing the luciferase reporter gene was used to transform stem internode and axillary bud explants. Putative transformants were regenerated on selection-free medium using our previously established in vitro regeneration method. Explant type, genotype, effect of pre-culture, Agrobacterium concentration, a time period of infection and varying periods of co-culture with bacteria were tested for the transformation frequency. The highest frequency of transformation was obtained with stem internode explants pre-cultured for 2 days, infected with Agrobacterium culture at the concentration of OD600 = 0.5 for 10 min and co-cultivated with Agrobacterium for 48 h. Out of the two genotypes tested, P. balsamifera exhibited a higher transformation rate in comparison to P. angustifolia. The primary transformants that exhibited luciferase activity in a bioluminescence assay under the CCD camera when subjected to polymerase chain reaction and Southern blot analysis revealed a stable single-copy integration of luc in their genomes. The reported protocol is highly reproducible and can be applied to other species of poplar; it will also be useful for future genetic engineering of one of the most important families of woody plants for sustainable development.

Parcela permanente de monitoreo de bosque de galería, en Puerto Gaitán, Meta

En 2010, Corpoica inició, en la altillanura disectada, la instalación y estudio de la estructura y composición florística de una parcela permanente de una hectárea localizada en la unidad bioclimática tropical denominada bosque de galería; ubicada en el municipio de Puerto Gaitán, Meta. La parcela, se trazó y demarcó; luego, se identificaron y censaron todos los individuos con DAP mayor de diez centímetros. De acuerdo con la composición florística, se encontraron 519 individuos pertenecientes a 72 especies, 56 géneros y 36 familias de plantas leñosas. Las familias con mayor riqueza de especies fueron Burseraceae (5), Euphorbiaceae (5) y Clusiaceae (5). Los usos principales de las 72 especies fueron: 32 maderables, 18 alimentación de fauna, 10 protectores de microcuencas, 5 leña, 3 frutales, 1 tinte y 1 ornamental. La mayor altura registrada para la parcela fue de 21 metros reportados por individuos de las especies chaparro de agua (Panopsis rubescens) y merecurillo blanco (Licania kunthiana). Las especies tuno (Miconia sp.) y quincedias (Tapirira guianensis) fueron las dos de las especies con mayor índice de valor de importancia (IVI) 29,5 % y 23,8 %, respectivamente. Se observó en los análisis de estructura vertical y horizontal que, el estrato medio (Em) presentó una cobertura del 46,9 %, que corresponde a un área basal de (6,87 m2), el estrato superior (Es) 45,7 % (6,69 m2) y el estrato inferior (Ei) 7,41 % (1,09 m2). Los resultados sugieren que estas áreas son diversas tanto en la estructura como en la composición florística y esta diversidad está siendo afectada por la perturbación antrópica ya que hay presencia de claros por efecto de la tala selectiva.

Contemporaneous climate directly controls broad‐scale patterns of woody plant diversity: a test by a natural experiment over 14,000 years

AbstractAimBroad‐scale diversity gradients are strongly correlated with climate. This correlation may reflect direct control of richness by contemporaneous climate. Alternatively, factors that were collinear with contemporaneous climate may have affected richness (e.g. temperature during the Last Glacial Maximum, LGM). We tested the hypothesis that contemporaneous climate directly controls broad‐scale patterns of richness. If climate directly (i.e. causally) controls richness, then when climate changes, richness should vary with climate through time in the same way that richness varies with climate through space. We also tested hypotheses that suggest that patterns of richness are primarily determined by processes associated with climate at the LGM.LocationNorth America, north of Mexico.MethodsWe used temperature changes over the last 14,000 years in North America as a ‘natural experiment’. We compared a proxy of woody plant family richness (based on fossilized pollen) with two reconstructions of the spatio‐temporal variation of temperature across North America at 1000‐year intervals.ResultsWe found that the spatial and temporal regional variations in richness of woody plant families, observed at 1000‐year intervals and expressed as a function of temperature, remained quite congruent during the changing climate since the end of the Pleistocene (the last c. 11,000 years). Between 14,000 and 11,000 yr bp, lags occurred during cooling periods, when richness remained anomalously high; however, richness was not anomalously low during the rapid warming in the late Pleistocene. Richness was significantly less strongly related to climate change since the LGM.Main conclusionsOur results provide a strong test of the hypothesis that, in ecological time, contemporaneous climate controls most of the broad‐scale variation in patterns of richness. Richness, independently of the responses of individual species, is likely to track current climate change, except possibly when temperature changes are very rapid.