Yunpeng Luo

Yunpeng Luo
Swiss Federal Institute for Forest, Snow and Landscape Research WSL | WSL · Forest Dynamics Research Unit

Doctor of Philosophy

About

15
Publications
7,232
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252
Citations
Introduction
Phenology variation under different nutrients(N,P); Phenology affected under CO2 fertilization; Phenology model coupled meterlogical factors and other important drivers (i.e. Nutrients)

Publications

Publications (15)
Article
Full-text available
Vegetation phenology has been viewed as the nature’s calendar and an integrative indicator of plant-climate interactions. The correct representation of vegetation phenology is important for models to accurately simulate the exchange of carbon, water, and energy between the vegetated land surface and the atmosphere. Remote sensing has advanced the m...
Article
Compared with gradual climate change, extreme climatic events have more direct and dramatic impacts on vegetation growth. However, the influence of climate extremes on important phenological periods, such as the end of the growing season (EOS), remains unclear. Here, we investigate the temporal trends of EOS across different biomes and quantify the...
Article
Remote sensing capabilities to monitor evergreen broadleaved vegetation are limited by the low temporal variability in the greenness signal. With canopy greenness computed from digital repeat photography (PhenoCam), we investigated how canopy greenness related to seasonal changes in leaf age and traits as well as variation of trees’ water fluxes (c...
Article
Existing research on autumn vegetation phenology is limited to phenological responses to gradual climate change. Considerably less attention has been paid to extreme climate events, resulting in a substantial gap in our understanding of the climatic response mechanism of vegetation autumn phenology. Therefore, in the present study, we used Moderate...
Article
Full-text available
Nutrient availability, especially of nitrogen (N) and phosphorus (P), is of major importance for every organism and at a larger scale for ecosystem functioning and productivity. Changes in nutrient availability and potential stoichiometric imbalance due to anthropogenic nitrogen deposition might lead to nutrient deficiency or alter ecosystem functi...
Article
Full-text available
Anthropogenic nitrogen (N) deposition and resulting differences in ecosystem N and phosphorus (P) ratios are expected to impact photosynthetic capacity, i.e. maximum gross primary productivity (GPPmax). However, the interplay between N and P availability with other critical resources on seasonal dynamics of ecosystem productivity remain largely unk...
Article
Full-text available
Mediterranean grasslands are highly seasonal and co-limited by water and nutrients. In such systems, little is known about root dynamics which may depend on individual plant properties and environment as well as seasonal water shortages and site fertility. Patterns of root biomass and activity are affected by the presence of scattered trees, grazin...
Article
Full-text available
To understand what is driving spatial flux variability within a savanna type ecosystem in central Spain, data of three co-located eddy covariance (EC) towers in combination with hyperspectral airborne measurements and footprint analysis were used. The three EC systems show consistent, and unbiased mass and energy fluxes. Nevertheless, instantaneous...
Article
Full-text available
Mediterranean grasslands are highly seasonal and co-limited by water and nutrients. In such systems little is known about root dynamics which may depend on plant habit and environment as well seasonal water shortages and site fertility. This latter factor is affected by the presence of scattered trees and site management including grazing, as well...
Article
Full-text available
Tree-grass ecosystems are widely distributed. However, their phenology has not yet been fully characterized. The technique of repeated digital photographs for plant phenology monitoring (hereafter referred as PhenoCam) provide opportunities for long-term monitoring of plant phenology, and extracting phenological transition dates (PTDs, e.g., start...
Article
Autumn phenological shifts induced by environmental change have resulted in substantial impacts on ecosystem processes. However, autumn phenology and its multiple related controlling factors have not been well studied. In this study, the spatiotemporal patterns of the end date of the vegetation growing season (EGS) and their multiple controls (clim...
Conference Paper
Full-text available
Tree-Grass ecosystems are global widely distributed (16-35% of the land surface). However, its phenology (es-pecially in water-limited areas) has not yet been well characterized and modeled. By using commercial digital cameras, continuous and relatively vast phenology data becomes available, which provides a good opportunity to monitor and develop...
Article
Full-text available
With the economic development of China, air pollutants are also growing rapidly in recent decades, especially in big cities of the country. To understand the relationship between economic condition and air pollutants in big cities, we analysed the socioeconomic indictorssuch as Gross Regional Product per capita (GRP per capita), the concentration o...

Questions

Questions (2)
Question
auxin transport direction
root auxin transport to stem?
Question
Phenology and soil nutrients
Literature with this topic just reach few...

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Cited By

Projects

Projects (5)
Project
Research background: Forests play a major role in regulating global carbon and water cycling, and land-atmosphere interactions. Global environmental change such as CO2 fertilization, drought, warming, precipitation variability, nitrogen deposition, and disturbances can have a large influence on forest vegetation and soils and thus on energy and carbon and water fluxes across spatial and temporal scales. As global change is expected to accelerate in the future, vegetation is likely to be affected by large-scale tree mortality, vegetation phenology, changes in forest cover and shifts in species composition. In addition, changes in soil stoichiometry and further changes in metabolic activity of influenced microbial community would possibly exert strong feedback on forest vegetation. This session focuses on novel insights on patterns, drivers and mechanisms governing forest carbon and water dynamics. We welcome submissions on dynamics of forest vegetation and soil microbial activities, and their impact on carbon and water fluxes, which conducted through observational, experimental and modeling approaches at local, regional or global spatial scales. Submission Infos: The abstract submission deadline is 10 January 2019, 13:00 CET: https://meetingorganizer.copernicus.org/EGU2019/abstractsubmission/32166 Hope to see you in Vienna! Date: 7–12 April 2019
Archived project
The conference aims to bring together young researchers within the broad domain of Earth system sciences – across spheres, scales and methods! >> present your research and broaden your knowledge in 3 thematic - a) understanding natural processes; b) anthropogenic activities; c) predictions and vulnerability of the Earth system - and 1 workshop session on research skills & methods >> meet and exchange with your peers during social events and horizontal discussions When? 13-15 March, 2019 Where? Max Planck Institute for Biogeochemistry, Jena, Germany Find out more: http://www.imprs-gbgc.de/espc2019/
Project
`Tree-grass´ ecosystems. Mixed tree-grass systems are widely distributed (~16-35% of global land-surface) vegetation formations such as tropical and Mediterranean savannas, the “waldsteppe” in Eurasia and culturally influenced vegetation types such as agro-forestry systems or grazed open-forests in Europe. Semi-arid tree-grass systems are considered one of the major contributors to the interannual variability of the global carbon cycle. Despite their wide distribution, Earth observation systems, and associated land-surface modeling development have been so far poorly adapted to the key structural and functional characteristics of tree-grass ecosystems. As consequence a significant uncertainty and bias in the assessments of energy, carbon, water and biogeochemical dynamics is often observed. Nutrient (N, P) imbalance. Human induced CO2 and N fertilization leads to a stoichiometric imbalance, which confers an important role to P availability and leads to shifts in C-N-P ratios and balances. N/P imbalances are particularly important in water-limited ecosystems, where the synergistic effect of water and nutrient (N and P) availability/imbalance could impact ecosystem functioning, structure, allocation patterns and the nutrient and carbon cycling, and ultimately how the ecosystem will respond to extreme drought events. Hence it is important to study the effects of N and P imbalances under different water regimes, in particular in mixed tree-grass at ecosystem scale. MaNiP project offers an original experimental design integrating cutting-edge approaches to study the combined effect of nutrient and water limiting factors on fundamental ecosystem, plant and soil processes. The experimental site is Majadas de Tietar (Casals et al., 2009) located in western Spain (39°56′25″N 5°46′29″W). The ecosystem is a typical “Iberic Dehesa”, which is characterized by an herbaceous stratum of native pasture and sparse trees, for the majority (~98%) Quercus ilex. The tree density is about 20–25 trees/ha⁠, the fractional cover of trees is about 20%, mean DBH of 46 cm, and a canopy height of about 8 m. (El-Madany et al., 2018). The herbaceous layer is composed of native annual species of the three main functional plant forms (grasses, forbs and legumes), whose fractional cover varies seasonally and is characterized by important inter-annual variations in the seasonal dynamics related to the onset of the dry period. Fluxes were measured with the eddy covariance technique with two different systems, one at ecosystem scale to characterize the fluxes of the whole ecosystem (15.5 m above ground), and one at 1.65 m above ground in an open space to measure the fluxes of the well-established understory grass layer. A combination of lysimeters, sap flow meters, high resolution spectrometers, digital repeat photography, airborne hyperspectral remote sensing, minirhizotrones, and soil respiration chambers are jointly used in the experiment. The main objectives are, first, to evaluate the response of the ecosystem functioning to fertilization and stoichiometric imbalance between N and P, and second to develop methods based on novel remote sensing information to characterized responses in ecosystem functions. More information (news, funding agencies and related projects) can be found in our website: https://www.bgc-jena.mpg.de/bgi/index.php/Research/BAIE Check out here for updates on datasets and codes: https://zenodo.org/communities/manip/?page=1&size=20