Nuevos registros para la flora vascular de Colombia presentes en la Orinoquia y reseña histórica de las expediciones botánicas a la región

18 new records to the vascular flora of Colombia found in the Orinoquia region are recorded: Duguetia riberensis Aristeg. ex Maas & Boon, Trigynaea duckei (R .E. Fr.) R. E. Fr. (Annonaceae); Tassadia medinae (Morillo) Morillo (Apocynaceae); Jaracanda orinocensis Sandw. (Bignoniaceae); Polycarpaea corymbosa (L.) Lam. var. brasiliensis (Cambess.) Chodat & Hassl. (Caryophyllaceae); Murdannia burchellii (C. B. Clarke) M. Pell. y M. aff. triquetra (Wall. ex C. B. Clarke) G.Brückn (Commelinaceae); Enterolobium barinense L. Cárdenas & Rodr.-Carr., Machaerium tovarense Pittier, Muellera crucisrubierae (Pittier) M. Sousa, and Tachigali davidsei Zarucchi & Herend. (Leguminosae); Nectandra bartlettiana Lasser (Lauraceae); Lindernia brachyphylla Pennell ex Steyerm. (Linderniaceae); Campomanesia aromatica (Aubl.) Griseb. (Myrtaceae); Christiana africana DC. (Malvaceae); Dulacia cyanocarpa Sleumer (Olacaceae); Phyllanthus microphyllus Kunth (Phyllanthaceae), and Gouania wurdackii Steyerm. (Rhamnaceae). These species were collected in the states of Arauca and Vichada in Colombia. Aspects related with the taxonomy and nomenclature of these new records, geographical distributions, and affinities with the flora of the Llanos of Venezuela as well as other regions with floristic similarities are discussed, and information about the exploration in the region is documented.Se registran 18 novedades para la flora vascular de Colombia a partir de ejemplares recolectados en la región dela Orinoquia. Los nuevos registros corresponden a: Duguetia riberensis Aristeg. ex Maas & Boon, Trigynaeaduckei (R. E. Fr.) R. E. Fr. (Annonaceae); Tassadia medinae (Morillo) Morillo (Apocynaceae); Jaracandaorinocensis Sandw. (Bignoniaceae); Polycarpaea corymbosa (L.) Lam. var. brasiliensis (Cambess.) Chodat &Hassl. (Caryophyllaceae); Murdannia burchellii (C. B. Clarke) M. Pell. y M. aff. triquetra (Wall. ex C. B. Clarke)G. Brückn (Commelinaceae); Enterolobium barinense L. Cárdenas & Rodr.-Carr., Machaerium tovarense Pittier,Muellera crucisrubierae (Pittier) M. Sousa y Tachigali davidsei Zarucchi & Herend. (Leguminosae), Nectandrabartlettiana Lasser (Lauraceae); Lindernia brachyphylla Pennell ex Steyerm. (Linderniaceae); Campomanesiaaromatica (Aubl.) Griseb. (Myrtaceae); Christiana africana DC. (Malvaceae); Dulacia cyanocarpa Sleumer(Olacaceae); Phyllanthus microphyllus Kunth (Phyllanthaceae) y Gouania wurdackii Steyerm. (Rhamnaceae).Estas especies fueron recolectadas en los departamentos de Arauca y Vichada. Se discuten aspectos relacionadoscon la taxonomía y nomenclatura de estos nuevos registros, su distribución geográfica, sus afinidades con la florapresente en la Orinoquia venezolana y regiones con características florísticas similares. Se agrega una reseñahistórica de las exploraciones en los llanos colombianos

Nuevos registros para la flora vascular de Colombia presentes en la Orinoquia y reseña histórica de las expediciones botánicas a la región

Se registran 18 novedades para la flora vascular de Colombia a partir de ejemplares recolectados en la región de la Orinoquia. Los nuevos registros corresponden a: Duguetia riberensis Aristeg. ex Maas & Boon, Trigynaea duckei (R. E. Fr.) R. E. Fr. (Annonaceae); Tassadia medinae (Morillo) Morillo (Apocynaceae); Jaracanda orinocensis Sandw. (Bignoniaceae); Polycarpaea corymbosa (L.) Lam. var. brasiliensis (Cambess.) Chodat & Hassl. (Caryophyllaceae); Murdannia burchellii (C. B. Clarke) M. Pell. y M. aff. triquetra (Wall. ex C. B. Clarke) G. Brückn (Commelinaceae); Enterolobium barinense L. Cárdenas & Rodr.-Carr., Machaerium tovarense Pittier, Muellera crucisrubierae (Pittier) M. Sousa y Tachigali davidsei Zarucchi & Herend. (Leguminosae), Nectandra bartlettiana Lasser (Lauraceae); Lindernia brachyphylla Pennell ex Steyerm. (Linderniaceae); Campomanesia aromatica (Aubl.) Griseb. (Myrtaceae); Christiana africana DC. (Malvaceae); Dulacia cyanocarpa Sleumer (Olacaceae); Phyllanthus microphyllus Kunth (Phyllanthaceae) y Gouania wurdackii Steyerm. (Rhamnaceae). Estas especies fueron recolectadas en los departamentos de Arauca y Vichada. Se discuten aspectos relacionados con la taxonomía y nomenclatura de estos nuevos registros, su distribución geográfica, sus afinidades con la flora presente en la Orinoquia venezolana y regiones con características florísticas similares. Se agrega una reseña histórica de las exploraciones en los llanos colombianos

Nuevos registros para la flora vascular de Colombia presentes en la Orinoquia y reseña histórica de las expediciones botánicas a la región

18 new records to the vascular flora of Colombia found in the Orinoquia region are recorded: Duguetia riberensis Aristeg. ex Maas & Boon, Trigynaea duckei (R .E. Fr.) R. E. Fr. (Annonaceae); Tassadia medinae (Morillo) Morillo (Apocynaceae); Jaracanda orinocensis Sandw. (Bignoniaceae); Polycarpaea corymbosa (L.) Lam. var. brasiliensis (Cambess.) Chodat & Hassl. (Caryophyllaceae); Murdannia burchellii (C. B. Clarke) M. Pell. y M. aff. triquetra (Wall. ex C. B. Clarke) G.Brückn (Commelinaceae); Enterolobium barinense L. Cárdenas & Rodr.-Carr., Machaerium tovarense Pittier, Muellera crucisrubierae (Pittier) M. Sousa, and Tachigali davidsei Zarucchi & Herend. (Leguminosae); Nectandra bartlettiana Lasser (Lauraceae); Lindernia brachyphylla Pennell ex Steyerm. (Linderniaceae); Campomanesia aromatica (Aubl.) Griseb. (Myrtaceae); Christiana africana DC. (Malvaceae); Dulacia cyanocarpa Sleumer (Olacaceae); Phyllanthus microphyllus Kunth (Phyllanthaceae), and Gouania wurdackii Steyerm. (Rhamnaceae). These species were collected in the states of Arauca and Vichada in Colombia. Aspects related with the taxonomy and nomenclature of these new records, geographical distributions, and affinities with the flora of the Llanos of Venezuela as well as other regions with floristic similarities are discussed, and information about the exploration in the region is documented.Se registran 18 novedades para la flora vascular de Colombia a partir de ejemplares recolectados en la región dela Orinoquia. Los nuevos registros corresponden a: Duguetia riberensis Aristeg. ex Maas & Boon, Trigynaeaduckei (R. E. Fr.) R. E. Fr. (Annonaceae); Tassadia medinae (Morillo) Morillo (Apocynaceae); Jaracandaorinocensis Sandw. (Bignoniaceae); Polycarpaea corymbosa (L.) Lam. var. brasiliensis (Cambess.) Chodat &Hassl. (Caryophyllaceae); Murdannia burchellii (C. B. Clarke) M. Pell. y M. aff. triquetra (Wall. ex C. B. Clarke)G. Brückn (Commelinaceae); Enterolobium barinense L. Cárdenas & Rodr.-Carr., Machaerium tovarense Pittier,Muellera crucisrubierae (Pittier) M. Sousa y Tachigali davidsei Zarucchi & Herend. (Leguminosae), Nectandrabartlettiana Lasser (Lauraceae); Lindernia brachyphylla Pennell ex Steyerm. (Linderniaceae); Campomanesiaaromatica (Aubl.) Griseb. (Myrtaceae); Christiana africana DC. (Malvaceae); Dulacia cyanocarpa Sleumer(Olacaceae); Phyllanthus microphyllus Kunth (Phyllanthaceae) y Gouania wurdackii Steyerm. (Rhamnaceae).Estas especies fueron recolectadas en los departamentos de Arauca y Vichada. Se discuten aspectos relacionadoscon la taxonomía y nomenclatura de estos nuevos registros, su distribución geográfica, sus afinidades con la florapresente en la Orinoquia venezolana y regiones con características florísticas similares. Se agrega una reseñahistórica de las exploraciones en los llanos colombianos

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Phylogenetic diversity of Amazonian tree communities

This is the peer reviewed version of the following article: Honorio Coronado, E. N., Dexter, K. G., Pennington, R. T., Chave, J., Lewis, S. L., Alexiades, M. N., Alvarez, E., Alves de Oliveira, A., Amaral, I. L., Araujo-Murakami, A., Arets, E. J. M. M., Aymard, G. A., Baraloto, C., Bonal, D., Brienen, R., Cerón, C., Cornejo Valverde, F., Di Fiore, A., Farfan-Rios, W., Feldpausch, T. R., Higuchi, N., Huamantupa-Chuquimaco, I., Laurance, S. G., Laurance, W. F., López-Gonzalez, G., Marimon, B. S., Marimon-Junior, B. H., Monteagudo Mendoza, A., Neill, D., Palacios Cuenca, W., Peñuela Mora, M. C., Pitman, N. C. A., Prieto, A., Quesada, C. A., Ramirez Angulo, H., Rudas, A., Ruschel, A. R., Salinas Revilla, N., Salomão, R. P., Segalin de Andrade, A., Silman, M. R., Spironello, W., ter Steege, H., Terborgh, J., Toledo, M., Valenzuela Gamarra, L., Vieira, I. C. G., Vilanova Torre, E., Vos, V., Phillips, O. L. (2015), Phylogenetic diversity of Amazonian tree communities. Diversity and Distributions, 21: 1295–1307. doi: 10.1111/ddi.12357, which has been published in final form at 10.1111/ddi.12357Aim: To examine variation in the phylogenetic diversity (PD) of tree communities across geographical and environmental gradients in Amazonia. Location: Two hundred and eighty-three c. 1 ha forest inventory plots from across Amazonia. Methods: We evaluated PD as the total phylogenetic branch length across species in each plot (PDss), the mean pairwise phylogenetic distance between species (MPD), the mean nearest taxon distance (MNTD) and their equivalents standardized for species richness (ses.PDss, ses.MPD, ses.MNTD). We compared PD of tree communities growing (1) on substrates of varying geological age; and (2) in environments with varying ecophysiological barriers to growth and survival. Results: PDss is strongly positively correlated with species richness (SR), whereas MNTD has a negative correlation. Communities on geologically young- and intermediate-aged substrates (western and central Amazonia respectively) have the highest SR, and therefore the highest PDss and the lowest MNTD. We find that the youngest and oldest substrates (the latter on the Brazilian and Guiana Shields) have the highest ses.PDss and ses.MNTD. MPD and ses.MPD are strongly correlated with how evenly taxa are distributed among the three principal angiosperm clades and are both highest in western Amazonia. Meanwhile, seasonally dry tropical forest (SDTF) and forests on white sands have low PD, as evaluated by any metric. Main conclusions: High ses.PDss and ses.MNTD reflect greater lineage diversity in communities. We suggest that high ses.PDss and ses.MNTD in western Amazonia results from its favourable, easy-to-colonize environment, whereas high values in the Brazilian and Guianan Shields may be due to accumulation of lineages over a longer period of time. White-sand forests and SDTF are dominated by close relatives from fewer lineages, perhaps reflecting ecophysiological barriers that are difficult to surmount evolutionarily. Because MPD and ses.MPD do not reflect lineage diversity per se, we suggest that PDss, ses.PDss and ses.MNTD may be the most useful diversity metrics for setting large-scale conservation priorities.FINCyT - PhD studentshipSchool of Geography of the University of LeedsRoyal Botanic Garden EdinburghNatural Environment Research Council (NERC)Gordon and Betty Moore FoundationEuropean Union's Seventh Framework ProgrammeERCCNPq/PELDNSF - Fellowshi

Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models

Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs

Phylogenetic diversity of Amazonian tree communities

Aim: To examine variation in the phylogenetic diversity (PD) of tree communities across geographical and environmental gradients in Amazonia. Location: Two hundred and eighty-three c. 1 ha forest inventory plots from across Amazonia. Methods: We evaluated PD as the total phylogenetic branch length across species in each plot (PDss), the mean pairwise phylogenetic distance between species (MPD), the mean nearest taxon distance (MNTD) and their equivalents standardized for species richness (ses.PDss, ses.MPD, ses.MNTD). We compared PD of tree communities growing (1) on substrates of varying geological age; and (2) in environments with varying ecophysiological barriers to growth and survival. Results: PDss is strongly positively correlated with species richness (SR), whereas MNTD has a negative correlation. Communities on geologically young- and intermediate-aged substrates (western and central Amazonia respectively) have the highest SR, and therefore the highest PDss and the lowest MNTD. We find that the youngest and oldest substrates (the latter on the Brazilian and Guiana Shields) have the highest ses.PDss and ses.MNTD. MPD and ses.MPD are strongly correlated with how evenly taxa are distributed among the three principal angiosperm clades and are both highest in western Amazonia. Meanwhile, seasonally dry tropical forest (SDTF) and forests on white sands have low PD, as evaluated by any metric. Main conclusions: High ses.PDss and ses.MNTD reflect greater lineage diversity in communities. We suggest that high ses.PDss and ses.MNTD in western Amazonia results from its favourable, easy-to-colonize environment, whereas high values in the Brazilian and Guianan Shields may be due to accumulation of lineages over a longer period of time. White-sand forests and SDTF are dominated by close relatives from fewer lineages, perhaps reflecting ecophysiological barriers that are difficult to surmount evolutionarily. Because MPD and ses.MPD do not reflect lineage diversity per se, we suggest that PDss, ses.PDss and ses.MNTD may be the most useful diversity metrics for setting large-scale conservation priorities

Tree height integrated into pantropical forest biomass estimates

Copyright © 2012 European Geosciences Union. This is the published version available at http://www.biogeosciences.net/9/3381/2012/bg-9-3381-2012.htmlAboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions: 1. What is the best H-model form and geographic unit to include in biomass models to minimise site-level uncertainty in estimates of destructive biomass? 2. To what extent does including H estimates derived in (1) reduce uncertainty in biomass estimates across all 327 plots? 3. What effect does accounting for H have on plot- and continental-scale forest biomass estimates? The mean relative error in biomass estimates of destructively harvested trees when including H (mean 0.06), was half that when excluding H (mean 0.13). Power- and Weibull-H models provided the greatest reduction in uncertainty, with regional Weibull-H models preferred because they reduce uncertainty in smaller-diameter classes (≤40 cm D) that store about one-third of biomass per hectare in most forests. Propagating the relationships from destructively harvested tree biomass to each of the 327 plots from across the tropics shows that including H reduces errors from 41.8 Mg ha−1 (range 6.6 to 112.4) to 8.0 Mg ha−1 (−2.5 to 23.0). For all plots, aboveground live biomass was −52.2 Mg ha−1 (−82.0 to −20.3 bootstrapped 95% CI), or 13%, lower when including H estimates, with the greatest relative reductions in estimated biomass in forests of the Brazilian Shield, east Africa, and Australia, and relatively little change in the Guiana Shield, central Africa and southeast Asia. Appreciably different stand structure was observed among regions across the tropical continents, with some storing significantly more biomass in small diameter stems, which affects selection of the best height models to reduce uncertainty and biomass reductions due to H. After accounting for variation in H, total biomass per hectare is greatest in Australia, the Guiana Shield, Asia, central and east Africa, and lowest in east-central Amazonia, W. Africa, W. Amazonia, and the Brazilian Shield (descending order). Thus, if tropical forests span 1668 million km2 and store 285 Pg C (estimate including H), then applying our regional relationships implies that carbon storage is overestimated by 35 Pg C (31–39 bootstrapped 95% CI) if H is ignored, assuming that the sampled plots are an unbiased statistical representation of all tropical forest in terms of biomass and height factors. Our results show that tree H is an important allometric factor that needs to be included in future forest biomass estimates to reduce error in estimates of tropical carbon stocks and emissions due to deforestation

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century