Michael J. O’Brien
A5066029436- Ecology and Vegetation Dynamics Studies
- Forest ecology and management
- Plant Water Relations and Carbon Dynamics
- Plant and animal studies
- Plant Surface Properties and Treatments
- Archaeology and ancient environmental studies
- Mycorrhizal Fungi and Plant Interactions
- Species Distribution and Climate Change
- Forest Ecology and Biodiversity Studies
- Wildlife Ecology and Conservation
- Postharvest Quality and Shelf Life Management
- Classical Philosophy and Thought
- Conservation, Biodiversity, and Resource Management
- Animal Ecology and Behavior Studies
- Remote Sensing and LiDAR Applications
- Tree-ring climate responses
- Historical and Cultural Archaeology Studies
- Rangeland and Wildlife Management
- Plant Physiology and Cultivation Studies
- Seedling growth and survival studies
- Classical Antiquity Studies
- Agroforestry and silvopastoral systems
- Forest Management and Policy
- Tree Root and Stability Studies
- Historical, Religious, and Philosophical Studies
Estacion Experimental de Zonas Aridas
2015-2024
Consejo Superior de Investigaciones Científicas
2016-2024
Universidad Rey Juan Carlos
2019-2024
Wayne State University
2019-2024
University College London
2024
Unidades Centrales Científico-Técnicas
2024
University of Missouri
1997-2022
Texas A&M University – San Antonio
2022
University of Zurich
2011-2021
National Museum of Natural History
2020
Summary Accumulating evidence highlights increased mortality risks for trees during severe drought, particularly under warmer temperatures and increasing vapour pressure deficit ( VPD ). Resulting forest die‐off events have consequences ecosystem services, biophysical biogeochemical land–atmosphere processes. Despite advances in monitoring, modelling experimental studies of the causes tree death from individual to global scale, a general mechanistic understanding realistic predictions...
NASA's Global Ecosystem Dynamics Investigation (GEDI) is collecting spaceborne full waveform lidar data with a primary science goal of producing accurate estimates forest aboveground biomass density (AGBD). This paper presents the development models used to create GEDI's footprint-level (~25 m) AGBD (GEDI04_A) product, including description datasets and procedure for final model selection. The fit our are from compilation globally distributed spatially temporally coincident field airborne...
Summary Forest dieback caused by drought‐induced tree mortality has been observed world‐wide. Forecasting which trees in locations are vulnerable to is important predict the consequences of drought on forest structure, biodiversity and ecosystem function. In this paper, our central aim was compile a synthesis traits associated abiotic variables that can be used mortality. We reviewed literature specifically links functional site conditions (i.e. edaphic biotic conditions), targeting studies...
Increasing frequency of extreme climatic events can disrupt ecosystem processes and destabilize functioning. Biodiversity may dampen these negative effects environmental perturbations to provide greater stability. We assessed the plant diversity on resistance, recovery stability experimental grassland ecosystems in response recurring summer drought over 7 yr. Plant biomass production was reduced during treatment compared with control plots. However, effect relatively less pronounced at high...
Summary Tree size shapes forest carbon dynamics and determines how trees interact with their environment, including a changing climate. Here, we conduct the first global analysis of among‐site differences in aboveground biomass stocks fluxes are distributed tree size. We analyzed repeat censuses from 25 large‐scale (4–52 ha) plots spanning broad climatic range over five continents to characterize biomass, woody productivity, mortality vary diameter. examined median, dispersion, skewness...
Current policy is driving renewed impetus to restore forests return ecological function, protect species, sequester carbon and secure livelihoods. Here we assess the contribution of tree planting ecosystem restoration in tropical sub-tropical Asia; synthesize evidence on mortality growth planted trees at 176 sites structural biodiversity recovery co-located actively restored naturally regenerating forest plots. Mean was 18% 1 year after planting, increasing 44% 5 years. Mortality varied...
One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles proximity adult plants. Although evidence shows that plant-specific soil pathogens can drive CDD, trees also form key mutualisms with mycorrhizal fungi, may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree exhibit weaker CDD than arbuscular species. We further...
Relatively, little is known about the relationship between biodiversity and ecosystem functioning in forests, especially tropics. We describe Sabah Biodiversity Experiment: a large-scale, long-term field study on island of Borneo. The project aims at understanding tree species diversity lowland dipterocarp rainforest during restoration following selective logging. experiment planned to run for several decades (from seed adult tree), so here we focus introducing its experimental design...
Summary Drought regimes can be characterized by the variability in quantity of rainfall and duration rainless periods. However, most research on plant response to drought has ignored impacts variation, especially with regard influence nonstructural carbohydrates ( NSC s) promoting resistance. To test hypothesis that these components differentially affect dynamics seedling resistance, we tracked tissues tropical tree seedlings manipulations volume frequency water applied. concentrations...
I: Introduction II: The Clouds III: Other Plays 1: Acharnians 2: Knights 3: Wasps 4: Peace 5: Birds 6: Lysistrate 7: Thesmophoriazusai 8: Frogs 9: Assembly of Women 10: Plutos IV: Conclusion Notes Index
The mutualism between plants and arbuscular mycorrhizal fungi (AMF) is widespread has persisted for over 400 million years. Although this depends on fair resource exchange fungi, inequality exists among partners despite mechanisms that regulate trade. Here, we use (33) P (14) C isotopes a split-root system to test preferential allocation reciprocal rewards in the plant-AMF symbiosis by presenting plant with two AMF differ cooperativeness. We found received more from less cooperative presence...
Abstract A life‐history trade‐off between low mortality in the dark and rapid growth light is one of most widely accepted mechanisms underlying plant ecological strategies tropical forests. Differences functional traits are thought to underlie these distinct strategies; however, very few studies have shown relationships demographic rates within a group. We present 8 years data from saplings 15 species Dipterocarpaceae planted into logged‐over forest Malaysian Borneo, four key traits: wood...
Arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) associations are critical for host-tree performance. However, how correlate with the latitudinal tree beta-diversity remains untested. Using a global dataset of 45 forest plots representing 2,804,270 trees across 3840 species, we test AM EcM contribute to total its components (turnover nestedness) all trees. We find rather than predominantly decreasing turnover increasing nestedness latitude, probably because wide distributions do not...
Abstract Aim Soil microorganisms are essential for the functioning of terrestrial ecosystems. Although soil microbial communities and functions linked to tree species composition diversity, there has been no comprehensive study generality or context dependence these relationships. Here, we examine diversity–soil biomass respiration relationships across environmental gradients using a global network diversity experiments. Location Boreal, temperate, subtropical tropical forests. Time period...
Experiments under controlled conditions have established that ecosystem functioning is generally positively related to levels of biodiversity, but it unclear how widespread these effects are in real-world settings and whether they can be harnessed for restoration. We used remote-sensing data from the first decade a long-term, field-scale tropical restoration experiment initiated 2002 test diversity planted trees affected recovery 500-ha area selectively logged forest measured using multiple...
Abstract The stress‐gradient hypothesis predicts a higher frequency of facilitative interactions as resource limitation increases. Under severe limitation, it has been suggested that facilitation may revert to competition, and identifying the presence well determining magnitude this shift is important for predicting effect climate change on biodiversity plant community dynamics. In study, we perform meta‐analysis compare temporal differences species diversity productivity under nurse (...
Abstract Aim Mapping tree species richness across the tropics is of great interest for effective conservation and biodiversity management. In this study, we evaluated potential full‐waveform lidar data mapping by relating measurements vertical canopy structure, as a proxy occupation niche space, to richness. Location Tropics. Time period Present. Major taxa studied Trees. Methods First, characteristics structure 15 study sites using (simulated) large‐footprint (22 m diameter) related these...
Furbearer Management in North America maintains wild furbearer populations at sustainably harvestable, scientifically determined and socially acceptable levels. management impacts numerous wildlife habitats, human health, safety property. Achieving balance the of furbearers is not always an easy task partly because regulated trapping, a controversial technique, plays critical role this balance. Steps have been taken by professionals to improve humaneness trapping through development...