1,721,775 research outputs found
Lindsaea linduensis (Lindsaeaceae, Polypodiales), a new fern species from Sulawesi, Indoensia
No full textCicuzza, Daniele, Kessler, Michael (2012): Lindsaea linduensis (Lindsaeaceae, Polypodiales), a new fern species from Sulawesi, Indonesia. Phytotaxa 65 (1): 36-40, DOI: 10.11646/phytotaxa.65.1.4, URL: http://biotaxa.org/Phytotaxa/article/view/phytotaxa.65.1.
The impact of population processes on patterns of species richness: lessons from elevational gradients
No full textIn the last few years, considerable headway has been made towards understanding patterns of species richness along latitudinal and elevational gradients, mostly by focussing on the influences of surface area, climatic factors, evolutionary history, and stochastic processes. However, the potential impact of population-level processes in determining or modifying patterns of species richness has largely been neglected, partly due to the difficulty of gathering such data for numerous species along geographical or ecological gradients. Based on two empirical examples, I here show that dispersal and the resulting source-sink effects modify patterns of plant species richness along elevation gradients, and that the inclusion or exclusion of such sink populations alters the perception of the diversity patterns and hence our interpretation of them. I argue that population processes should be taken into account when studying patterns of species richness, especially at scales at which dispersal is common in the taxon under consideration.
Zusammenfassung
In den letzten Jahren hat sich unser Verständnis von Mustern des Artenreichtums entlang von geographischen Gradienten deutlich weiterentwickelt, vor allem durch die Berücksichtigung der Einflüsse von Fläche, Klimafaktoren, der evolutionären Geschichte und stochastischen Prozessen. Der potentielle Einfluss von Prozessen auf der Populationsebene auf Diversitätsmuster ist jedoch weitgehend vernachlässigt worden, teilweise aufgrund der Schwierigkeiten die mit der Erhebung von belastbaren Populationsdaten für zahlreiche Arten entlang von geographischen oder ökologischen Gradienten verbunden sind. Anhand von zwei emprischen Beispielen zeige ich hier, dass Ausbreitung und damit verbundene Quellen-Senken-Effekte Muster der Pflanzendiversität entlang von Höhengradienten modifizieren und dass die Berücksichtigung solcher Senkenpopulationen unsere Wahrnehmung von Diversitätsmustern beeinflussen. Populationsprozesse sollten folglich bei der Betrachtung von Diversitätsmustern berücksichtigt werden, vor allem auf räumlichen Skalen auf denen Ausbreitung der untersuchten Organismengruppe häufig stattfinden
Fern endemism and its correlates: contribution from an elevational transect in Costa Rica
No full textWe studied the distribution patterns of endemic ferns along an elevational gradient of 3400 m in Costa Rica, Central America. We related the endemism patterns of the whole species set and separated for life forms and microhabitats according to topography and environmental factors. Fern species were surveyed in 156 plots each with an area of 400 m(2), with up to five plots at every elevational step of 100 m. Global range size for every species was compiled from literature data, and species restricted to the mountain range from Costa Rica and adjacent western Panama were defined as endemic (24.5% of all species recorded). We found patterns of endemism rates mostly peaking at mid-elevation, but when separated for different life forms and microhabitats, some deviations from the overall pattern emerged. High constant humidity and reduced surface area were closely related to high levels of endemism. High humidity is discussed as a general predictor for high endemism rates in concert with highest overall richness. Restricted area of elevational belts, indicating a fragmented habitat, leads to a higher degree of population isolation and thus species differentiation. However, both interpretations were not fully supported by our data. Most importantly, endemism rates were fairly low on mountain tops that have the smallest available area in a topographically highly fragmented setting. In contrast, endemic species were more common than widespread species at the highest elevations. History and climatic shifts are assumed to play a role in this respect
Using the internet to aid in discovery of unrecognized type material
No full textSteudel, Bastian, Kessler, Michael, Nyffeler, Reto (2012): Using the internet to aid in discovery of unrecognized type material. Phytotaxa 62 (1): 13-24, DOI: 10.11646/phytotaxa.62.1.4, URL: http://biotaxa.org/Phytotaxa/article/view/phytotaxa.62.1.
Sticherus cubensis J. Gonzales, comb. nov.
No full textSticherus cubensis (Underw.) J.Gonzales, comb. nov. Dicranopteris cubensis Underwood (1907: 253). Type: — CUBA. Barbacoa: El Yunque, March 1903, Underwood & Earle 1416 (holotype NY!). Distribution and ecology: —Cuba, known only from the type. Ecology unknown.Published as part of Gonzales, Jasivia & Kessler, Michael, 2011, A synopsis of the Neotropical species of Sticherus (Gleicheniaceae), with descriptions of nine new species, pp. 1-54 in Phytotaxa 31 on page 23, DOI: 10.11646/phytotaxa.31.1.1, http://zenodo.org/record/489464
Sticherus brittonii Nakai 1950
No full textSticherus brittonii (Maxon) Nakai (1950: 15) Dicranopteris brittonii Maxon (1922a: 47). Gleichenia brittonii (Maxon) C.Chr. (Christensen 1934: 106). Type: — TRINIDAD: Mount Tocuche, Britton 1352 (holotype US!, isotype NY!). Distribution and ecology: —Endemic to Mount Tocuche, Trinidad, to 1000 m. Habitat unknown.Published as part of Gonzales, Jasivia & Kessler, Michael, 2011, A synopsis of the Neotropical species of Sticherus (Gleicheniaceae), with descriptions of nine new species, pp. 1-54 in Phytotaxa 31 on page 20, DOI: 10.11646/phytotaxa.31.1.1, http://zenodo.org/record/489464
FIGURE 1 in A new species of Elaphoglossum sect. Lepidoglossa (Dryopteridaceae) from Bolivia
No full textFIGURE 1. Examples of differences of morphological traits between Elaphoglossum dannoritzeri (BO = Bolivia) and three geographical populations (PE = Peru, EC = Ecuador, VE = Venezuela) of E. mathewsii. For significance levels, see Table 1. Box plots show the median values (horizontal lines), upper and lower quartiles (box limits) and 95% confidence intervals (brackets).Published as part of Kessler, Michael, 2013, A new species of Elaphoglossum sect. Lepidoglossa (Dryopteridaceae) from Bolivia, pp. 33-39 in Phytotaxa 77 (2) on page 34, DOI: 10.11646/phytotaxa.77.2.3, http://zenodo.org/record/506681
Sticherus tepuiensis Smith 1990
No full textSticherus tepuiensis Smith (1990: 253). Type:— VENEZUELA. Bolívar, Meseta del Jaua, Cerro Sarisariñama, porción NE, bosque enano por encima y al borde de la Sima Mayor, 4°41’40”N, 64°13’20”W, 1320 m, 13 February 1974, Steyermark 109036 (holotype US). Distribution and ecology:— Endemic to montane forests at 1300–2100 m in southeastern Venezuela in Bolívar (Cerro Jaua, Cerro Sarisariñama) and Amazonas (Cerro Duida), and in adjacent Guyana (Pakaraima Mts.).Published as part of Gonzales, Jasivia & Kessler, Michael, 2011, A synopsis of the Neotropical species of Sticherus (Gleicheniaceae), with descriptions of nine new species, pp. 1-54 in Phytotaxa 31 on page 48, DOI: 10.11646/phytotaxa.31.1.1, http://zenodo.org/record/489464
Sticherus gracilis Copeland 1947
No full textSticherus gracilis (Mart.) Copeland (1947: 27) Mertensia gracilis Martius (1834: 107, tab. 59). Gleichenia gracilis (Mart.) Moore (1862: 378). Type: — BRAZIL. Santa Catarina, Martius s.n. (holotype M?, not located). Distribution and ecology: — Endemic to central and southeastern Brazil (Distrito Federal, Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina). Grows in semihumid forests and along forest margins in the cerrado region, at ca. 1100–1300 m.Published as part of Gonzales, Jasivia & Kessler, Michael, 2011, A synopsis of the Neotropical species of Sticherus (Gleicheniaceae), with descriptions of nine new species, pp. 1-54 in Phytotaxa 31 on pages 27-28, DOI: 10.11646/phytotaxa.31.1.1, http://zenodo.org/record/489464
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