Life Sciences Commons^™

Technical Note: Novel Estimates Of The Leaf Relative Uptake Rate Of Carbonyl Sulfide From Optimality Theory, Georg Wohlfahrt, Albin Hammerle, Felix M. Spielmann, Florian Kitz, Chuixiang Yi

Publications and Research

In order to estimate the gross primary productivity (GPP) of terrestrial ecosystems from the canopy uptake of carbonyl sulfide (COS), the leaf relative uptake rate (LRU) of COS with respect to carbon dioxide needs to be known a priori. Currently, the variability of the LRU between plant species in different biomes of the world is poorly understood, making the choice of an appropriate LRU uncertain and hampering further progress towards developing COS as an alternative tracer of GPP. Here we propose a novel approach for estimating LRU based on plant optimality principles, validate it against in situ leaf gas exchange …

Satellite Evidence Of Canopy-Height Dependence Of Forest Drought Resistance In Southwestern China, Peipei Xu, Wei Fang, Tao Zhou, Hu Li, Xiang Zhao, Spencer Berman, Ting Zhang, Chuixiang Yi

Publications and Research

The frequency and intensity of drought events are increasing with warming climate, which has resulted in worldwide forest mortality. Previous studies have reached a general consensus on the size-dependency of forest resistance to drought, but further understanding at a local scale remains ambiguous with conflicting evidence. In this study, we assessed the impact of canopy height on forest drought resistance in the broadleaf deciduous forest of southwestern China for the 2010 extreme drought event using linear regression and a random forest (RF) model. Drought condition was quantified with standardized precipitation evapotranspiration index (SPEI) and drought resistance was measured with the …

Elevated Growth And Biomass Along Temperate Forest Edges, Luca L. Morreale, Jonathan R. Thompson, Xiaojing Tang, Andrew B. Reinmann, Lucy R. Hutyra

Publications and Research

Fragmentation transforms the environment along forest edges. The prevailing narrative, driven by research in tropical systems, suggests that edge environments increase tree mortality and structural degradation resulting in net decreases in ecosystem productivity. We show that, in contrast to tropical systems, temperate forest edges exhibit increased forest growth and biomass with no change in total mortality relative to the forest interior. We analyze > 48,000 forest inventory plots across the north-eastern US using a quasi- experimental matching design. At forest edges adjacent to anthropogenic land covers, we report increases of 36.3% and 24.1% in forest growth and biomass, respectively. Inclusion of …

The Effects Of Late Spring Frost On Forest And Landscape Health And Recovery Of The Black Rock Forest, New York, Caroline Eco, Oliver Imhans, Aaron Davitt, Andrew B. Reinmann

Publications and Research

Projected changes in climate are expected to increase the frequency of late spring frost events in the Northeast US. Such events can be harmful to trees because freezing temperatures that occur after leaf-out can damage or kill young leaves. The resultant defoliation typically forces a second flush of leaves, but delays canopy development, which in turn delays the onset of canopy carbon uptake and alters canopy thermal properties. In this study, we analyzed a recent freeze event that occurred on 8-9 May 2020 (DOY 129-130) at Black Rock Forest (BRF), which is in the Hudson Highlands of southeastern New York …

Spatial Upscaling Of Forest Response To Drought, Wei Fang, Peipei Xu, Tao Zhao, Xiang Zhao, Hui Luo, George Hendrey, Chuixiang Yi

Publications and Research

We have integrated the observational capability of satellite remote sensing with plot-scale tree ring data to up-scale the evaluation of forest responses to drought. Satellite data, such as Normalized Difference Vegetation Index (NDVI), can provide a spatially continuous measure with limited temporal coverage, while tree Ring Width Index (RWI) provides accurate assessment with much longer time series local scales. Here, we explored the relationship between RWI and NDVI of three dominant species in the Southwestern United States (SWUS), and predicted RWI spatial distribution from 2001 to 2017 based on MODIS 1-km resolution NDVI data with stringent quality control. We detected …

Evaluation Of The Uncertainty In Satellite-Based Crop State Variable Retrievals Due To Site And Growth Stage Specific Factors And Their Potential In Coupling With Crop Growth Models, Nathaniel Levitan, Yanghui Kang, Mutlu Özdogan, Vincenzo Magliulo, Paulo Castillo, Fred Moshary, Barry Gross

Publications and Research

Coupling crop growth models and remote sensing provides the potential to improve our understanding of the genotype x environment x management (G X E X M) variability of crop growth on a global scale. Unfortunately, the uncertainty in the relationship between the satellite measurements and the crop state variables across different sites and growth stages makes it diffcult to perform the coupling. In this study, we evaluate the effects of this uncertainty with MODIS data at the Mead, Nebraska Ameriflux sites (US-Ne1, US-Ne2, and US-Ne3) and accurate, collocated Hybrid-Maize (HM) simulations of leaf area index (LAI) and canopy light use …

Microbial Diversity In Urban Environments: Concern For Antibiotic Resistance, Ality Aghedo, Mangala Tawde, Nazrul I. Khandaker

Publications and Research

We are almost oblivious to the presence of microorganisms in our daily lives, but they exist and come into contact with us all the time. While some bacteria are harmless, and even beneficial, other bacteria can cause infections. A common treatment to bacterial infections is antibiotics and the success of an antibiotic depends on the resistance of the bacteria to the antibiotic. We conducted experiments to identify the types of bacteria that can be found on surfaces or within soil environments that come into contact with a vast number of people on a daily basis and how this can affect …

Forest Drought Resistance Distinguished By Canopy Height, Wei Fang, Peipei Xu, Tao Zhou, George Hendrey, Xiang Zhao

Publications and Research

How are the survival and growth of trees under severe drought affected by their size? While some studies have shown that large trees are more vulnerable to drought than smaller trees, others found that small trees are the more vulnerable. We explored the potential relationships between canopy height and forest responses to drought indicated by tree mortality, tree ring width index (RWI), and normalized difference vegetation index (NDVI) in the southwestern United States (SWUS) in 2002. In that year many trees had zero tree ring growth due to mortality and dieback, presumably related to drought-stress. With RWI data from a …

Dynamic Responses Of Tree-Ring Growth To Multiple Dimensions Of Drought, Wei Fang, Shan Gao, Ruishun Liu, Tao Zhou, Chuixiang Yi, Ruijie Liu, Xiang Zhao, Hui Luo

Publications and Research

Droughts, which are characterized by multiple dimensions including frequency, duration, severity and onset timing, can impact tree growth profoundly. Different dimensions of drought influence tree growth independently or jointly, which makes the development of accurate predictions a formidable challenge. Measurement-based tree-ring data have obvious advantages for studying the drought responses of trees. Here, we explored the use of abundant tree-ring records for quantifying regional response patterns to key dimensions of drought. Specifically, we designed a series of regional-scaled “natural experiments”, based on 357 tree-ring chronologies from Southwest USA and location-matched monthly water balance anomalies, to reveal how tree-ring growth responds …

Bifurcated Response Of A Regional Forest To Drought, Wei Fang, Chuixiang Yi, Guangwei Mu, George Hendrey, Sergio M. Vicente-Serrano, Tao Zhou, Shan Gao, Peipei Xu

Publications and Research

Several lines of evidence suggest that forest growth in many regions is declining as a consequence of changing climate. To predict the fate of forests in the future, a quantitative understanding of how the key climate variables (insolation, precipitation and temperature) interact with forests to cause the decline is a pressing need. Here we use a regionally-averaged tree-ring width index (RWIr ) to quantify forest growth in the Southwest United States (SWUS). We show that over a period of 100 years, SWUS RWIr bifurcated into forest stands with enhanced (healthy) and reduced (declining) branches when regressed on shortwave-radiation and temperature, …

A Global Study Of Gpp Focusing On Light-Use Efficiency In A Random Forest Regression Model, Suhua Wei, Chuixiang Yi, Wei Fang, George Hendrey

Publications and Research

Light-use efficiency (LUE) is at the core of mechanistic modeling of global gross primary production (GPP). However, most LUE estimates in global models are satellite based and coarsely measured with emphasis on environmental variables. Others are from eddy covariance towers with much greater spatial and temporal data quality and emphasis on mechanistic processes, but in a limited number of sites. In this study, we conducted a comprehensive global study of tower-based LUE from 237 FLUXNET towers, and scaled up LUEs from in situ tower level to global biome level. We integrated the tower-based LUE estimates with key environmental and biological …

The Potential Of Forest Biomass Inversion Based On Vegetation Indices Using Multi-Angle Chris/Proba Data, Qiang Wang, Yong Pang, Zengyuan Li, Guoqing Sun, Erxue Chen, Wenge Ni-Meister

Publications and Research

Multi-angle remote sensing can either be regarded as an added source of uncertainty for variable retrieval, or as a source of additional information, which enhances variable retrieval compared to traditional single-angle observation. However, the magnitude of these angular and band effects for forest structure parameters is difficult to quantify. We used the Discrete Anisotropic Radiative Transfer (DART) model and the Zelig model to simulate the forest canopy Bidirectional Reflectance Distribution Factor (BRDF) in order to build a look-up table, and eight vegetation indices were used to assess the relationship between BRDF and forest biomass in order to find the sensitive …

Stably Stratified Canopy Flow In Complex Terrain, Xiyan Xu, Chuixiang Yi, Eric Kutter

Publications and Research

Stably stratified canopy flow in complex terrain has been considered a difficult condition for measuring net ecosystem–atmosphere exchanges of carbon, water vapor, and energy. A long-standing advection error in eddy-flux measurements is caused by stably stratified canopy flow. Such a condition with strong thermal gradient and less turbulent air is also difficult for modeling. To understand the challenging atmospheric condition for eddy-flux measurements, we use the renormalized group (RNG) k–ε turbulence model to investigate the main characteristics of stably stratified canopy flows in complex terrain. In this two-dimensional simulation, we imposed persistent constant heat flux at ground surface and linearly …

Striking The Balance: Challenges And Perspectives For The Protected Areas Network In Northeastern European Russia, Svetlana V. Degteva, Vasily I. Ponomarev, Sasha W. Eisenman, Vyacheslav Dushenkov

Publications and Research

Increasing anthropogenic pressure on the largest remaining tracts of old-growth boreal forest in Europe necessitates additional conservation of ecosystems and biodiversity in northeastern European Russia. In a regional network comprising 8 % of the Nenets Autonomous District and 13.5 % of the Komi Republic, 248 areas have varying protected statuses as state nature reserves (zapovedniks), national parks, reserves/sanctuaries (zakazniks), or natural monuments. Due to increased natural resource extraction in this relatively pristine area, designation of additional protected areas is critical for the protection of key ecological sites. The history of ecological preservation in these regions is herein described, and recent …

Tipping Point Of A Conifer-Based Ecosystem Under Severe Drought, Kaicheng Huang, Chuixiang Yi, Donghai Wu, Tao Zhou, Xiang Zhao, William J. Blanford, Suhua Wei, Hao Wu, Du Ling, Zheng Li

Publications and Research

Drought-induced tree mortality has recently received considerable attention. Questions have arisen over the necessary intensity and duration thresholds of droughts that are sufficient to trigger rapid forest declines. The values of such tipping points leading to forest declines due to drought are presently unknown. In this study, we have evaluated the potential relationship between the level of tree growth and concurrent drought conditions with data of the tree growth-related ring width index (RWI) of the two dominant conifer species (Pinus edulis and Pinus ponderosa) in the Southwestern United States (SWUS) and the meteorological drought-related standardized precipitation evapotranspiration index …

Reading With The Grain: On Vin Nardizzi’S Wooden Os: Shakespeare’S Theatres And England’S Trees, Steven Swarbrick

Publications and Research

No abstract provided.

Notes On The Diet Of The Malay Civet (Viverra Tangalunga) And Other Civets In Logged And Unlogged Lowland Dipterocarp Rain Forests In Sabah, Borneo, Christina P. Colon, John B. Sugau

Publications and Research

Civet diets were examined in a logged and unlogged Bornean rain forest. Malay civets (Viverra tangalunga) consumed invertebrates, fruit, rodents, insectivores, birds, snakes and lizards, and appear to show preference for centipedes and scorpions. Other civet species consumed fruit, such as figs, Connarus sp. and Annona sp., particularly in the unlogged forest, but also consumed invertebrates and vertebrates. Reduced fruit consumption observed in the logged forest may be due to lower availability and may be offset by increased consumption of invertebrates. The increased overlap in diet between Malay civets and other civets in disturbed areas may lead to …

Ecology Of The Malay Civet (Viverra Tangalunga) In A Logged And An Unlogged Forest In Sabah, East Malaysia, Christina P. Colon

Publications and Research

Malay civets in a dipterocarp rain forest were studied from December, 1995, through June, 1997, in the Ulu Segama Forest Reserve in Sabah, East Malaysia. To investigate the basic ecology of this species and explore the potential impact of selective logging, data on home range, activity and diet were collected on study animals in an unlogged and a selectively logged forest, and comparisons made.

Density in the unlogged forest was 1/0.46 km² , and 1/1.07 km² in the logged forest. Mean home range size based on a 95% minimum convex polygon was 110 ha. and did not differ …

The Use Of Plot Surveys For The Study Of Ethnobotanical Knowledge: A Brunei Dusun Example, Jay H. Bernstein, Roy Ellen, Bantong Bin Antaran

Publications and Research

This paper describes a technique for using plot surveys to measure individual informants' ethnobotanical knowledge of forests, as applied to the Dusun community of Merimbun in Brunei. Two knowledgeable but non-literate Dusun informants enumerated marked plots of both recent and old secondary growth mixed dipterocarp forest near the village. They were able to provide names (other than life-forms or the most general basic and intermediate categories) for 86-97% of species growing in the plots. Between 152 and 170 plant names were elicited by the surveys. In all cases, about 88% of the names were at the basic naming level and …

Licuala Palms In Brunei Dusun Ethnobotany, Jay H. Bernstein, Roy F. Ellen

Publications and Research

Several species of Licuala occur in the Merimbun area of Tutong district, Brunei Darussalam. One kind of Licuala, called benjiru by the local Dusun population, is often collected for sale as a vegetable. While Licuala is not generally considered an important economic plant, overharvesting in the Merimbun area suggests that conservation measures may be needed to protect it from local extinction. Besides benjiru, other kinds of Licuala recognized by the Dusun are called silad and ukang. The three kinds of Licuala do not have one overall name in the Dusun language, but constitute a covert category at the "intermediate" ethnobotanical …