Author
Oliver L. Phillips
Other affiliations: University of York, University of Brasília, Center for Plant Conservation ...read more
Bio: Oliver L. Phillips is an academic researcher from University of Leeds. The author has contributed to research in topics: Biodiversity & Amazon rainforest. The author has an hindex of 98, co-authored 336 publications receiving 50569 citations. Previous affiliations of Oliver L. Phillips include University of York & University of Brasília.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, the authors employed the acetylene inhibition technique and the 15N-nitrate labeling method to quantify N2 and N2O emission rates for long-term experimentally N-enriched treatments in primary and secondary tropical montane forest.
Abstract: Nitrogen (N) deposition is projected to substantially increase in the tropics over the coming decades, which is expected to lead to enhanced N saturation and gaseous N emissions from tropical forests (via NO, N2O, and N2). However, it is unclear how N deposition in tropical forests influences both the magnitude of gaseous loss of nitrogen and its partitioning into the N2 and N2O loss mechanisms. Here, for the first time, we employed the acetylene inhibition technique and the 15N-nitrate labeling method to quantify N2 and N2O emission rates for long-term experimentally N-enriched treatments in primary and secondary tropical montane forest. We found that during laboratory incubation under aerobic conditions long-term increased N addition of up to 100 kg N ha−1 yr−1 at Jianfengling forest, China, did not cause a significant increase in either N2O or N2 emissions, or N2O/N2. However, under anaerobic conditions, N2O emissions decreased and N2 emissions increased with increasing N addition in the secondary forest. These changes may be attributed to substantially greater N2O reduction to N2 during denitrification, further supported by the decreased N2O/N2 ratio with increasing N addition. No such effects were observed in the primary forest. In both forests, N addition decreased the contribution of denitrification while increasing the contribution of co-denitrification and heterotrophic nitrification to N2O production. Denitrification was the predominant pathway to N2 production (98–100%) and its contribution was unaffected by N addition. Despite the changes in the contributions of denitrification to N2O gas emissions, we detected no change in the abundance of genes associated with denitrification. While the mechanisms for these different responses are not yet clear, our results indicate that the effects of N deposition on gaseous N loss were ecosystem-specific in tropical forests and that the microbial processes responsible for the production of N gases are sensitive to N inputs.
37 citations
University of York1, Norwegian University of Life Sciences2, Manchester Metropolitan University3, University of Leeds4, International Union for Conservation of Nature and Natural Resources5, University College London6, Ghent University7, Royal Museum for Central Africa8, University of Jos9, University of Helsinki10, Academy of Sciences of the Czech Republic11, Charles University in Prague12, Addis Ababa University13, University of Yaoundé I14, Mbarara University of Science and Technology15, Gembloux Agro-Bio Tech16, University of Erlangen-Nuremberg17, United Nations Environment Programme18, University of Canterbury19, National Park Service20, Wageningen University and Research Centre21, University of Guelph22, Sewanee: The University of the South23, University of Montpellier24, University of Kisangani25, World Agroforestry Centre26, Missouri Botanical Garden27, University of Burundi28, Smithsonian Tropical Research Institute29, Kunming Institute of Botany30, Université libre de Bruxelles31, American Museum of Natural History32, University of Bayreuth33, Helmholtz Centre for Environmental Research - UFZ34, Karatina University35, Colorado State University36, Environmental Change Institute37, University of the Sunshine Coast38, College of African Wildlife Management39, University of Edinburgh40, University of Dundee41, Cape Peninsula University of Technology42, National University of Rwanda43, University of Gothenburg44, Mountains of the Moon University45, University of Southampton46, University of Cambridge47, Wuhan University48, BirdLife International49, University of Lincoln50, University of Florence51, University of Freiburg52, University of Bonn53, University of Dschang54, African Wildlife Foundation55, University of British Columbia56, Center for International Forestry Research57, Czech University of Life Sciences Prague58, Bioversity International59, National University of Singapore60, University of Toronto61, Yale University62, Florida International University63, Bangor University64, Rothamsted Research65, University of Liberia66
TL;DR: In this paper, the authors assemble and analyse a dataset of structurally intact old-growth forests spanning 44 montane sites in 12 African countries and find that the average AGC stock of these sites has a value of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1-164.2).
Abstract: Tropical forests store 40–50 per cent of terrestrial vegetation carbon1. However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests2. Owing to climatic and soil changes with increasing elevation3, AGC stocks are lower in tropical montane forests compared with lowland forests2. Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1–164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network4 and about 70 per cent and 32 per cent higher than averages from plot networks in montane2,5,6 and lowland7 forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa8. We find that the low stem density and high abundance of large trees of African lowland forests4 is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse9,10 and carbon-rich ecosystems.
37 citations
University of Leeds1, University of York2, University of Cambridge3, University of Copenhagen4, University of Twente5, Royal Botanic Garden Edinburgh6, Frankfurt Zoological Society7, Catholic University of Leuven8, University of Dar es Salaam9, Sokoine University of Agriculture10, University College London11
TL;DR: A repeatable method to estimate carbon storage values and associated 95% confidence intervals for all five IPCC carbon pools for data-deficient regions is presented, using a combination of existing inventory data and systematic literature searches, weighted to ensure the final values are regionally specific.
Abstract: Monitoring landscape carbon storage is critical for supporting and validating climate change mitigation policies. These may be aimed at reducing deforestation and degradation, or increasing terrestrial carbon storage at local, regional and global levels. However, due to data-deficiencies, default global carbon storage values for given land cover types such as ‘lowland tropical forest’ are often used, termed ‘Tier 1 type’ analyses by the Intergovernmental Panel on Climate Change (IPCC). Such estimates may be erroneous when used at regional scales. Furthermore uncertainty assessments are rarely provided leading to estimates of land cover change carbon fluxes of unknown precision which may undermine efforts to properly evaluate land cover policies aimed at altering land cover dynamics. Here, we present a repeatable method to estimate carbon storage values and associated 95% confidence intervals (CI) for all five IPCC carbon pools (aboveground live carbon, litter, coarse woody debris, belowground live carbon and soil carbon) for data-deficient regions, using a combination of existing inventory data and systematic literature searches, weighted to ensure the final values are regionally specific. The method meets the IPCC ‘Tier 2’ reporting standard. We use this method to estimate carbon storage over an area of33.9 million hectares of eastern Tanzania, reporting values for 30 land cover types. We estimate that this area stored 6.33 (5.92–6.74) Pg C in the year 2000. Carbon storage estimates for the same study area extracted from five published Africa-wide or global studies show a mean carbon storage value of ~50% of that reported using our regional values, with four of the five studies reporting lower carbon storage values. This suggests that carbon storage may have been underestimated for this region of Africa. Our study demonstrates the importance of obtaining regionally appropriate carbon storage estimates, and shows how such values can be produced for a relatively low investment.
36 citations
Hans ter Steege1, Terry W. Henkel2, Nora Helal1, Beatriz Schwantes Marimon3 +234 more•Institutions (86)
TL;DR: Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors.
Abstract: 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.
36 citations
TL;DR: It appears that the conservation value of most "edge" forests in this region has not yet been compromised substantially, and one explanation for the findings may be that western Amazonian tree species are naturally faster growing and more disturbance adapted than those farther east.
Abstract: : Anthropogenic edge effects can compromise the conservation value of mature tropical forests. To date most edge-effect research in Amazonia has concentrated on forests in relatively seasonal locations or with poor soils in the east of the basin. We present the first evaluation from the relatively richer soils of far western Amazonia on the extent to which mature forest biomass, diversity, and composition are affected by edges. In a southwestern Amazonian landscape we surveyed woody plant diversity, species composition, and biomass in 88 × 0.1 ha samples of unflooded forest that spanned a wide range in soil properties and included samples as close as 50 m and as distant as >10 km from anthropogenic edges. We applied Mantel tests, multiple regression on distance matrices, and other multivariate techniques to identify anthropogenic effects before and after accounting for soil factors and spatial autocorrelation. The distance to the nearest edge, access point, and the geographical center of the nearest community (“anthropogenic-distance effects”) all had no detectable effect on tree biomass or species diversity. Anthropogenic-distance effects on tree species composition were also below the limits of detection and were negligible in comparison with natural environmental and spatial factors. Analysis of the data set's capacity to detect anthropogenic effects confirmed that the forests were not severely affected by edges, although because our study had few plots within 100 m of forest edges, our confidence in patterns in the immediate vicinity of edges is limited. It therefore appears that the conservation value of most “edge” forests in this region has not yet been compromised substantially. We caution that because this is one case study it should not be overinterpreted, but one explanation for our findings may be that western Amazonian tree species are naturally faster growing and more disturbance adapted than those farther east.
Resumen: Los cambios antropogenicos pueden comprometer el valor de conservacion de bosques tropicales maduros. A la fecha, la mayor parte de la investigacion del efecto de borde en la Amazonia se ha concentrado en bosques en localidades relativamente temporales o con suelos pobres en el este de la cuenca. Presentamos la primera evaluacion del grado en que la biomasa, diversidad y composicion de bosques maduros son afectadas por los bordes en los suelos relativamente mas ricos en el lejano oeste de la Amazonia. Muestreamos la diversidad, composicion de especies y biomasa de plantas lenosas en 88 parcelas de 0.1 ha en bosques no inundables en un paisaje del suroeste de la Amazonia con una amplia gama de caracteristicas edaficas y que incluian muestras tan cercanas como 50 m y tan distantes como >10 km de los bordes antropogenicos. Aplicamos pruebas de Mantel, regresion multiple en matrices de distancia y otras tecnicas multivariadas para identificar los efectos antropogenicos antes y despues de considerar los factores edaficos y la autocorrelacion espacial. La distancia al borde, punto de acceso y centro geografico de la comunidad mas cercana (efectos antropogenicos-distancia) no tuvieron efecto detectable sobre la biomasa o diversidad de especies de arboles. Los efectos antropogenicos-distancia sobre la composicion de especies de arboles tambien estuvieron debajo de los limites de deteccion y fueron insignificantes en comparacion con los factores ambientales y espaciales. El analisis de la capacidad del conjunto de datos para detectar efectos antropogenicos confirmo que los bosques no fueron afectados por los bordes severamente, aunque nuestra confianza en los patrones de la vecindad inmediata del borde es limitada, porque nuestro estudio tenia pocas parcelas a menos de 100 m del borde. Por lo tanto, parece que el valor de conservacion de la mayoria de los bosques “borde” en esta region aun no ha sido comprometido sustancialmente. Prevenimos que este es un estudio no debe ser sobre interpretado porque solo es un caso, pero una explicacion para nuestros resultados puede ser que las especies de arboles de la Amazonia occidental estan naturalmente mas adaptadas a perturbaciones y tienen crecimiento mas rapido que las del oriente.
36 citations
Cited by
More filters
28 Jul 2005
TL;DR: PfPMP1）与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201
14,171 citations
TL;DR: In this paper, the use of the maximum entropy method (Maxent) for modeling species geographic distributions with presence-only data was introduced, which is a general-purpose machine learning method with a simple and precise mathematical formulation.
13,120 citations
University of Melbourne1, Stony Brook University2, City University of New York3, Princeton University4, University of Lausanne5, University of California, Berkeley6, University of Alaska Fairbanks7, National Institute of Water and Atmospheric Research8, Commonwealth Scientific and Industrial Research Organisation9, University of São Paulo10, University of Missouri11, Consejo Nacional de Ciencia y Tecnología12, University of Kansas13, Landcare Research14, AT&T15, McGill University16, James Cook University17, Swiss Federal Institute for Forest, Snow and Landscape Research18
TL;DR: This work compared 16 modelling methods over 226 species from 6 regions of the world, creating the most comprehensive set of model comparisons to date and found that presence-only data were effective for modelling species' distributions for many species and regions.
Abstract: Prediction of species' distributions is central to diverse applications in ecology, evolution and conservation science. There is increasing electronic access to vast sets of occurrence records in museums and herbaria, yet little effective guidance on how best to use this information in the context of numerous approaches for modelling distributions. To meet this need, we compared 16 modelling methods over 226 species from 6 regions of the world, creating the most comprehensive set of model comparisons to date. We used presence-only data to fit models, and independent presence-absence data to evaluate the predictions. Along with well-established modelling methods such as generalised additive models and GARP and BIOCLIM, we explored methods that either have been developed recently or have rarely been applied to modelling species' distributions. These include machine-learning methods and community models, both of which have features that may make them particularly well suited to noisy or sparse information, as is typical of species' occurrence data. Presence-only data were effective for modelling species' distributions for many species and regions. The novel methods consistently outperformed more established methods. The results of our analysis are promising for the use of data from museums and herbaria, especially as methods suited to the noise inherent in such data improve.
7,589 citations
Australian National University1, Stockholm Resilience Centre2, University of Copenhagen3, McGill University4, Stellenbosch University5, University of Wisconsin-Madison6, Wageningen University and Research Centre7, Stockholm University8, Royal Swedish Academy of Sciences9, Potsdam Institute for Climate Impact Research10, Commonwealth Scientific and Industrial Research Organisation11, International Livestock Research Institute12, University College London13, Stockholm Environment Institute14, The Energy and Resources Institute15, University of California, San Diego16, Royal Institute of Technology17
TL;DR: An updated and extended analysis of the planetary boundary (PB) framework and identifies levels of anthropogenic perturbations below which the risk of destabilization of the Earth system (ES) is likely to remain low—a “safe operating space” for global societal development.
Abstract: The planetary boundaries framework defines a safe operating space for humanity based on the intrinsic biophysical processes that regulate the stability of the Earth system. Here, we revise and update the planetary boundary framework, with a focus on the underpinning biophysical science, based on targeted input from expert research communities and on more general scientific advances over the past 5 years. Several of the boundaries now have a two-tier approach, reflecting the importance of cross-scale interactions and the regional-level heterogeneity of the processes that underpin the boundaries. Two core boundaries—climate change and biosphere integrity—have been identified, each of which has the potential on its own to drive the Earth system into a new state should they be substantially and persistently transgressed.
7,169 citations