The effects of human disturbance on vascular epiphyte in the Brazilian Atlantic Forest

The high pressure that anthropogenic activities places on tropical forests are pushing species and communities to the brink of local, regional or global extinctions. However, the consequences of the loss of species and their ecosystem functions are not well known. My thesis addresses the causes and consequences of human disturbance on vascular epiphytes in the Brazilian Atlantic forest (BAF). I sampled understory and canopy, across a gradient of habitat loss, i.e. pastureland, human-modified forests (HMFs) and old-growth forest. I found that habitat loss has driven a net loss of 91% of species exclusive to old-growth, and 90% of individuals. I also found the edge effect to be a ubiquitous landscape process extending at least 500 m within forests habitats, leaving just 19.4% of the whole of the BAF suitable for forest-dependant epiphytes. However, whilst endemic species (habitat specialised species) are more prone to disappear as consequence of habitat loss, species with larger dispersal ranges and the ability to colonize different forest types flourish or endure the harsh conditions after disturbance. Consequently, HMFs have low functional richness and low functional redundancy, meaning low resilience, whereas old-growth forests exhibit high ecological resilience. Habitat transformation also leads to the loss of a large set of ecosystem functions related to pollination and water cycling across strata. Hence preserving large continuous forests are probably the only pragmatic conservation strategy for vascular epiphytes in highly human-modified landscapes. However, human-modified forests still provide limited ecosystem functions that may increase because of initiatives to improve habitat amount.Open Acces

Edge influence on diversity of orchids in Andean cloud forests

Cloud forests harbor high levels of orchid diversity. However, due to the high fragmentation of these forests in the Andes, combined with the pressure for new agricultural land, orchid diversity is highly threatened. Despite this worrying scenario, few studies have assessed the effects of habitat loss specifically on orchid assemblages in the Andes. The aim of this study was to analyze the edge effect on orchids in cloud forest fragments of varying size. We measured forest structure, neighboring land cover and edge effect on orchid abundance, species richness and beta-diversity, by sampling assemblages along edge-to-interior transects in six different sized Andean (southwest Colombia) forest remnants. We recorded 11,127 stem-individuals of orchids in 141 species. Within the forest, edges sustained equal or more species than interior plots. Our results revealed neither patch metrics nor forest structure showed any significant association to orchid diversity at any scale. Nonetheless, from our observations in composition, the type of neighboring cover, particularly pastures, negatively influences interior species (richness and composition) in larger reserves. This might be due to the fact that some species found in interior plots tend to be confined, with sporadic appearances in regeneration forest and are very scarce or absent in pastures. Species richness differed significantly between matrix types. Our results suggest that (1) orchid diversity shows spatial variability in response to disturbances, but the response is independent from forest structure, patch size and patch geometry; (2) orchid communities are negatively affected by covers, and this pattern is reflected in reduced richness and high species turnover; (3) orchid richness edge effect across a pasture-interior gradient. Two forest management implications can be discerned from our results: (1) management strategies aiming to reduce edge effects may focus on improvement regeneration conditions around pasture lands; and (2) local scale management and conservation activities of natural forests in cloud forests will favor small reserves that harbor high levels of richness

Inventario orquideológico de la Reserva Bosque de Yotoco, Valle del Cauca

En la Reserva Bosque de Yotoco (76° 20' O, 3° 50' N, 1200 - 1700 m.s.n.m.) relicto de selva subandina de aproximadamente 500 ha, durante 3 años (marzo de 2006 y mayo de 2009) se realizaron búsquedas intensivas aleatorias de especies de la familia Orchidaceae. Hasta junio de 2009 se habían reportado 80 especies pertenecientes a 46 géneros, siendo los de mayor riqueza específica Epidendrum L. con 13 y Maxillaria Ruiz y Pav. con seis. Como exclusivas de algunas zonas fueron identificadas Macroclinium oberonia (Schltr.) Dodson y Porroglossum muscosum (Rchb. f.) Schltr.; como abundantes y ampliamente distribuidas Epidendrum porpax Rchb.f., Campylocentrum micranthum (Lindl.) Rolfe y Oncidium adelaidae Königer; y como poco abundantes Cryptocentrum latifolium Schltr. y Specklinia picta (Lindl.) Pridgeon and amp; M.W. Chase

The origin and speciation of orchids

SummaryOrchids constitute one of the most spectacular radiations of flowering plants. However, their origin, spread across the globe, and hotspots of speciation remain uncertain due to the lack of an up-to-date phylogeographic analysis.We present a new Orchidaceae phylogeny based on combined high-throughput and Sanger sequencing data, covering all five subfamilies, 17/22 tribes, 40/49 subtribes, 285/736 genera, and c. 7% (1921) of the 29 524 accepted species, and use it to infer geographic range evolution, diversity, and speciation patterns by adding curated geographical distributions from the World Checklist of Vascular Plants.The orchids' most recent common ancestor is inferred to have lived in Late Cretaceous Laurasia. The modern range of Apostasioideae, which comprises two genera with 16 species from India to northern Australia, is interpreted as relictual, similar to that of numerous other groups that went extinct at higher latitudes following the global climate cooling during the Oligocene. Despite their ancient origin, modern orchid species diversity mainly originated over the last 5 Ma, with the highest speciation rates in Panama and Costa Rica.These results alter our understanding of the geographic origin of orchids, previously proposed as Australian, and pinpoint Central America as a region of recent, explosive speciation

Efecto de los patrones del paisaje sobre la diversidad de orquídeas de bosques nublados del valle del cauca

Las prácticas antrópicas cambian la estructura y omposición del paisaje,modificando, alterando y transformando el hábitat natural de las especies (Turner,et al. 1998), causando perdida e n la diversidad y recambio en la estructura y composición de comunidades de varios grupos de organismos (Duelli et al.1990; Yahner 1988). Teniendo un efecto diferencial de acuerdo a la matriz. Se plantea la hipótesis de la reducción en la diversidad y la composición por la Estructura y composición del paisaje de relictos de bosques de niebla, puesto que en relictos fuertemente perturbados se disminuye la calidad del hábitat desde el borde hacia el interior del bosque debido al efecto de borde, este efecto de borde está influenciado por la vertiente y por el tipo de cobertura adyacente a cada relicto. Con el objetivo de evaluar esta hipótesis en orquídeas de bosques de niebla del Valle del Cauca, se seleccionaron seis reservas comunitarias; tres dispuestas en la Cordillera Occidental COCC y tres la Cordillera Central CCN, relictos de diferente tamaño, entre 9 a 231 Ha, rodeados con dos tipos de cobertura diferente,Regeneración y Pastura tres; en cada uno, se realizaron inventarios durante Enero y Septiembre de 2012 de las orquídeas en parcelas de 200 m2 (4 x 50 m)subdivididas en 10 parcelas de 5 x 4m perpendiculares al borde, con diez estaciones cada 5 m desde - 5 hasta 40 m. Adicionalmente, se evaluaron las variables ambientales como estructura arbórea utilizando el método “Point - centered quarter” y geometría de parche. Se registró información de 11.127 individuos, 136 especies y 39 morfoespecies distribuidas en 36 géneros, para una densidad de 30.908 plantas/ha. Se reportaron 16 especies endémicas y la Dracula andreettae (Luer) Luer como vulnerable (categorizada UICN - VU - D2). En términos de densidad la COCC presento un valor muy superior (4.84 vs 1.3 ind. /m2); en la CCN, este valor es mayor en las localidades de Dapa (6.7 ind. /m2) y Yotoco (5.3 ind. /m2) . Las cordilleras comparten el 53% de géneros (19 géneros), siendo exclusivos para la COCC solo el 27.7% (10 géneros). No se evidenciaron diferencias estadísticamente significativas en riqueza con las variables ambientales, sin embargo hay una relación positiva local entre la densidad y el área basal con la abundancia. Los patrones de distribución de las especies de orquídeas están relegados a tendencias y variabilidades locales, por tanto se hace difícil relacionar los indicadores de diversidad alfa para la identificación de estos, sin embargo el recambio de especies y la composición permiten caracterizar y definir mejor los patrones. A pesar de no encontrar diferencias significativas entre los bordes y el interior del bosque, entre el 58 al 100 % de las especies del interior del bosque están restringidas a este hábitat y se evidencian cambios en el tamaño poblacional y en la distribución de la composición, entre las distancias, además fueron negativamente relacionada la abundancia en la cobertura de pasturas frente al interior del bosque a una distancia de 35 m, por lo cual se recomienda realizar estudios que permitan expandir unidad de muestreo y determinar el impacto ecológico en gradiente mayor. Adicionalmente se reconoce el papel importante que las r eservas comunitarias cumplen en la conservación de estos ecosistemas que sustentan esta alta diversidad de especiesnthropogenic practices change the structure and composition of the landscape, modifying, altering and transforming the natural hábitat of the species, causing loss in diversity and turnover in the structure and composition of communities of various groups of organisms. With a differential effect according to the type of neighbor cover. The hypothesis of this work focuses on the landscape configuration and composition of relicts of cloud forests and the effect on diversity and composition of orchids, influenced by the slope and the type of cover adjacent to each patch. In order to test this hypothesis in cloud forest orchids of Valle del Cauca, we selected six community reserves located a long the Cordilleras, three arranged in the Cordillera Occidental Cordillera COCC and three one in Cordillera Centr al CCN, relict of different sizes between 9- 231 Ha, surrounded with two different types of coverage, Pasture and Regeneration, in each one, inventories were conducted during January and September 2012 for orchids in plots of 200 m2 (4 x 50 m) subdivided in to 10 plots of 5 x 4 m perpendicular to the edge, with ten stations every 5 m - 5 to 40 m. Additionally, environmental variables were evaluated as tree structure using the "Point - centered quarter" and patch geometry. Information was recorded from 11.127 individuals, 136 species and 39 morphospecies distributed in 36 genera, density of 30,908 plants / ha. 16 endemic species were reported and Dracula andreettae (Luer) Luer categorized as vulnerable (VU-D2 in IUCN). In terms of density the COCC present a much higher value (4.84 vs 1.3 ind./m2) in the CCN, this value is higher in the towns of Dapa (6.7 ind./m2) and Yotoco (5.3 ind./m2) . Cordilleras shared 53% of genera (19 genera), being exclusive to the COCC only 27.7% (10 genera). Changes in the abundance and composition of orchids, no statistically significant differences for the environmental variables againts richness, however there is a positive relationship between the local density and basal area with abundance. The distribution patterns of species o f orchids are relegated to local trends and variabilities, so it is difficult to relate the alpha diversity indicators for the identification of those with, however the species turnover and composition to characterize and define patterns . Although no sign ificant differences between the edges and the interior of the forest, but 58 to 100% of the forest interior species were restricted to this habitat and show changes in population size and distribution of the composition. Distances were negatively related in pastures, in terms of abundances, face Interior at distance of 35 m. We recommend make studies that expand the sampling unit and ecological effects in higher gradient. Additionally it recognizes the important role of Community reserves play in the conservation of this ecosystem that sustain this high species diversityMaestrí

Edge influence on diversity of orchids in Andean cloud forests

Cloud forests harbor high levels of orchid diversity. However, due to the high fragmentation of these forests in the Andes, combined with the pressure for new agricultural land, orchid diversity is highly threatened. Despite this worrying scenario, few studies have assessed the effects of habitat loss specifically on orchid assemblages in the Andes. The aim of this study was to analyze the edge effect on orchids in cloud forest fragments of varying size. We measured forest structure, neighboring land cover and edge effect on orchid abundance, species richness and beta-diversity, by sampling assemblages along edge-to-interior transects in six different sized Andean (southwest Colombia) forest remnants. We recorded 11,127 stem-individuals of orchids in 141 species. Within the forest, edges sustained equal or more species than interior plots. Our results revealed neither patch metrics nor forest structure showed any significant association to orchid diversity at any scale. Nonetheless, from our observations in composition, the type of neighboring cover, particularly pastures, negatively influences interior species (richness and composition) in larger reserves. This might be due to the fact that some species found in interior plots tend to be confined, with sporadic appearances in regeneration forest and are very scarce or absent in pastures. Species richness differed significantly between matrix types. Our results suggest that (1) orchid diversity shows spatial variability in response to disturbances, but the response is independent from forest structure, patch size and patch geometry; (2) orchid communities are negatively affected by covers, and this pattern is reflected in reduced richness and high species turnover; (3) orchid richness edge effect across a pasture-interior gradient. Two forest management implications can be discerned from our results: (1) management strategies aiming to reduce edge effects may focus on improvement regeneration conditions around pasture lands; and (2) local scale management and conservation activities of natural forests in cloud forests will favor small reserves that harbor high levels of richness

A new species of Campylocentrum (Orchidaceae:Angraecinae) from Colombia

Se describe e ilustra a Campylocentrum palominoi, una nueva especie de la Cordillera occidental de los Andes, departamento del Valle del Cauca (Colombia). Esta especie es similar a C. brenesii, de la cual difiere principalmente por los lóbulos laterales del labelo obtusos, ovados, subiguales, lóbulo medio sin papilas en la lámina y por el nectario sacciforme, angosto en la base y ancho en el ápice. Campylocentrum palominoi, a new species from the western Cordillera of the Andes, department of Valle del Cauca (Colombia), is described and illustrated. This species is similar to C. brenesii, from which it differs mainly by the subequal, ovate, obtuse lobes of the 3-veined lip, abscense of papillae at the middle lobe and the saccate spur which is widened towards the apex.

Inventario orquideológico de la Reserva Bosque de Yotoco, Valle del Cauca

En la Reserva Bosque de Yotoco (76° 20' O, 3° 50' N, 1200 - 1700 m.s.n.m.) relicto de selva subandina de aproximadamente 500 ha, durante 3 años (marzo de 2006 y mayo de 2009) se realizaron búsquedas intensivas aleatorias de especies de la familia Orchidaceae. Hasta junio de 2009 se habían reportado 80 especies pertenecientes a 46 géneros, siendo los de mayor riqueza específica Epidendrum L. con 13 y Maxillaria Ruiz y Pav. con seis. Como exclusivas de algunas zonas fueron identificadas Macroclinium oberonia (Schltr.) Dodson y Porroglossum muscosum (Rchb. f.) Schltr.; como abundantes y ampliamente distribuidas Epidendrum porpax Rchb.f., Campylocentrum micranthum (Lindl.) Rolfe y Oncidium adelaidae Königer; y como poco abundantes Cryptocentrum latifolium Schltr. y Specklinia picta (Lindl.) Pridgeon & M.W. Chase