Browsing by Autor "William D. Gosling"

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A simple and effective methodology for sampling modern pollen rain in tropical environments
(SAGE Publishing, 2003) William D. Gosling; Francis E. Mayle; Timothy J. Killeen; Marcelo E. Siles; Lupita Sanchez; Steve Boreham
To gain a better insight into the nature of palaeovegetation change in tropical ecosystems, more information needs to be gleaned from the limited number of fossil pollen records that exist. To achieve this, a detailed understanding of modern tropical ecosystems and the pollen they produce is required. To facilitate this, a practicable and effective mechanism for sampling modern pollen rain from the tropics is required. This paper presents a modified field methodology based upon three years of trapping experience in Noel Kempff Mercado National Park, Bolivia, and improved laboratory preparation methodologies. We demonstrate here a simple and very effective way to sample modern pollen rain in tropical environments using a funnel trap mounted on a stake containing cotton fibre as the trapping medium.
Centuries of compounding human influence on Amazonian forests
(National Academy of Sciences, 2025) Crystal N. H. McMichael; Mark B. Bush; Hans ter Steege; Dolores R. Piperno; William D. Gosling; Majoi N. Nascimento; Umberto Lombardo; Luiz de Souza Coêlho; Iêda Leão do Amaral; Francisca Dionízia de Almeida Matos
Recent evidence suggests that the ecological footprints of pre-Columbian Indigenous peoples in Amazonia persist in modern forests. Ecological impacts resulting from European colonization c. 1550 CE and the Amazonian Rubber Boom c. 1850 to 1920 CE are largely unexplored but could be important additive influences on forest structure and tree species composition. Using environmental niche models, we show the highest probabilities of pre-Columbian and colonial occupation sites, and hence human-induced ecological influences, occurred in forests along rivers. In many areas, the predicted pre-Columbian and colonial distributions overlap spatially with the potential for superimposed ecological influences. Environmental gradients are known to structure Amazonian vegetation composition, but they are also strong predictors of past human influence, both spatially and temporally. Our comparisons of model outputs with relative abundances of Amazonian tree species suggest that pre-Columbian and colonial-period ecological legacies are associated with modern forest composition.
Differentiation between Neotropical rainforest, dry forest, and savannah ecosystems by their modern pollen spectra and implications for the fossil pollen record
(Elsevier BV, 2008) William D. Gosling; Francis E. Mayle; Nicholas Tate; Timothy J. Killeen
Modern Pollen-Rain Characteristics of Tall <i>Terra Firme</i> Moist Evergreen Forest, Southern Amazonia
(Cambridge University Press, 2005) William D. Gosling; Francis E. Mayle; Nicholas Tate; Timothy J. Killeen
Abstract The paucity of modern pollen-rain data from Amazonia constitutes a significant barrier to understanding the Late Quaternary vegetation history of this globally important tropical forest region. Here, we present the first modern pollen-rain data for tall terra firme moist evergreen Amazon forest, collected between 1999 and 2001 from artificial pollen traps within a 500 × 20 m permanent study plot (14°34′50″S, 60°49′48″W) in Noel Kempff Mercado National Park (NE Bolivia). Spearman's rank correlations were performed to assess the extent of spatial and inter-annual variability in the pollen rain, whilst statistically distinctive taxa were identified using Principal Components Analysis (PCA). Comparisons with the floristic and basal area data of the plot (stems ≥10 cm d.b.h.) enabled the degree to which taxa are over/under-represented in the pollen rain to be assessed (using R-rel values). Moraceae/Urticaceae dominates the pollen rain (64% median abundance) and is also an important constituent of the vegetation, accounting for 16% of stems ≥10 cm d.b.h. and ca. 11% of the total basal area. Other important pollen taxa are Arecaceae (cf. Euterpe ), Melastomataceae/Combretaceae, Cecropia , Didymopanax , Celtis , and Alchornea . However, 75% of stems and 67% of the total basal area of the plot ≥10 cm d.b.h. belong to species which are unidentified in the pollen rain, the most important of which are Phenakospermum guianensis (a banana-like herb) and the key canopy-emergent trees, Erisma uncinatum and Qualea paraensis .
Thermal niche traits of high alpine plant species and communities across the tropical Andes and their vulnerability to global warming
(Wiley, 2019) Francisco Cuesta; Carolina Tovar; Luis D. Llambí; William D. Gosling; Stephan Halloy; Julieta Carilla; Priscilla Muriel; Rosa Isela Meneses; Stephan Beck; Carmen Ulloa Ulloa
Abstract Aim The climate variability hypothesis (CVH) predicts that locations with reduced seasonal temperature variation select for species with narrower thermal ranges. Here we (a) test the CVH by assessing the effect of latitude and elevation on the thermal ranges of Andean vascular plant species and communities, and (b) assess tropical alpine plants vulnerability to warming based on their thermal traits. Location High tropical Andes. Taxon Vascular plants. Methods Temperature data for 505 vascular plant species from alpine communities on 49 summits, were extracted from 29,627 georeferenced occurrences. Species thermal niche traits (TNTs) were estimated using bootstrapping for: minimum temperature, optimum (mean) temperature and breadth (maximum‐minimum). Plant community‐weighted scores were estimated using the TNTs of their constituent species. CVH was tested for species, biogeographical species groups and communities. Vulnerability to global warming was assessed for species, biogeographical species groups and communities. Results Species restricted to the equator showed narrower thermal niche breadth than species whose ranges stretch far from the equator, however, no difference in niche breadth was found across summits’ elevation. Biogeographical species groups distributed close to the equator and restricted to alpine regions showed narrower niche breadth than those with broader ranges. Community‐weighted scores of thermal niche breadth were positively related to distance from equator but not to elevation. Based on their TNTs, species restricted to equatorial latitudes and plant communities dominated by these species were identified as the most vulnerable to the projected 1.5°C warming, due to a potentially higher risk of losing thermal niche space. Main conclusions Our study confirms that the CVH applies to high tropical Andean plant species and communities, where latitude has a strong effect on the thermal niche breadth. TNTs are identified as suitable indicators of species’ vulnerability to warming and are suggested to be included in long‐term biodiversity monitoring in the Andes.