20171103

Author : Sten Gillner & Sandra Korn & Mathias Hofmann & Andreas Roloff

Year : 2017

Title :Contrasting strategies for tree species to cope with heat and dry conditions at urban sites


Journal :  Urban Ecosyst


Comment: Measurements of leaf gas exchange, leaf water potential, leaf surface temperature and chlorophyll-fluorescence were used for identification of specific response of Corylus corluna L., Ginkgo biloba L., Liriodendron tulipifera L., and Tilia cordata Mill. ‘Greenspire’. 

 The summer months in 2013 with a period of heat and drought over eight weeks only interrupted by two rainy days were appropriate to access tree’s strategies to cope with low water availability. 

 During the measurement period, the influence of high temperatures, high values of vapor pressure deficit (VPD) and low soil water availability on stomatal conductance, water-use efficiency (WUE) and leaf water potential (Ψmin, Ψmax ) was highest for Liriodendron followed by Ginkgo. 

 These species showed high …

20171027

Author : Hamed Majidzadeh, B. Graeme Lockaby, Robin Governo

Year : 2017

Title : Effect of home construction on soil carbon storage-A chronosequence case study


Journal :  Environmental Pollution


Comment: Previous research documents a significant reduction in SOC and TN, however, it is unclear if this decrease is a result of top soil removal or long-term soil sealing. 

In this study, soil biogeochemical properties were quantified beneath homes built on a crawl space at two depths (0-10 cm, and 10-20 cm). All homes, 11-114 years in age, were sampled in the Piedmont region of Alabama and Georgia, USA. 

The difference in SOC beneath homes and adjoining urban lawns showed a quadratic relation with age. Maximum SOC loss occurred at approximately fifty years. The same pattern was observed for Microbial biomass carbon : C ratio suggesting that the SOC content was decreasing beneath the homes for first fifty years, then increased afterward. 

The average SOC and TN content in the top 10 cm were respect…

20171020

Author : Subhadip Ghosh, Bryant C. Scharenbroch, Lai Fern Ow

Year : 2016

Title : Soil organic carbon distribution in roadside soils of Singapore


Journal :  Chemosphere


Comment: They characterized the soil organic carbon (SOC) in roadside soils across the city-state of Singapore. We tested three hypotheses that SOC contents (concentration and density) in Singapore would be positively related to above ground tree biomass, soil microbial biomass and land-use patterns.

 Singapore's roadside soils represent 4% of Singapore's land, but store 2.9 million Mg C (estimated range of 0.3-11 million Mg C). This amount of SOC is equivalent to 25% of annual anthropogenic
C emissions in Singapore. Soil organic C contents in Singapore's soils were not related to above ground vegetation or soil microbial biomass, whereas land-use patterns to best explain variance in SOC in Singapore's roadside soils.

20171013

Author :  Christopher D. Elvidge, Benjamin T. Tuttle, Paul C. Sutton, Kimberly E. Baugh,
Ara T. Howard, Cristina Milesi, Budhendra L. Bhaduri  and Ramakrishna Nemani 

Year : 2007

Title : Global Distribution and Density of Constructed Impervious Surfaces


Journal :  Sensors


Comment: They present the global inventory of the spatial distribution and density of
constructed impervious surface area (ISA). Examples of ISA include roads, parking lots,
buildings, driveways, sidewalks and other man-made surfaces. 

They found that 1.05% of the United States land area is impervious surface (83,337 km2) and 0.43 % of the world’s land surface (579,703 km2) is constructed impervious surface. 

China has more ISA than any other country (87,182 km2), but has only 67 m2 of ISA per person, compared to 297 m2 per person in the USA. The distribution of ISA in the world’s primary drainage basins indicates that watersheds damaged by ISA are primarily concentrated in the USA, Europe, Japan, China and India.

20171006

Author :   M. Hedblom & F. Lindberg & E. Vogel & J. Wissman & K. Ahrné

Year :  2017

Title : 
Estimating urban lawn cover in space and time: Case studies
in three Swedish cities

Journal : 
Urban Ecosyst

Comment

 They review the existing literature of lawn cover in cities and the different methodologies used for cover estimation. They found both pros and cons with NDVI and LiDAR data as well as manually interpreted aerial photos. During 50 years lawn area almost doubled in relative cover and 56% of them were continuously managed. Since lawns constitute large parts of the urban greenery and are costly to manage it is highly relevant to consider their social, ecological and cultural value compared to alternatives, e.g., meadows with less intensive management.

20170929

Author :   M. Rial, A. Martínez Cortizas, L. Rodríguez-Lado

Year :  2017

Title : 
Understanding the spatial distribution of factors controlling topsoil
organic carbon content in European soils

Journal : 
Science of the Total Environment

Comment

They present a modelling procedure for mapping and monitoring SOC contents that uses Visible-Near Infrared (VNIR) spectroscopic measurements and a series of environmental covariates to ascertain the key environmental processes that have a major contribution into SOC sequestration processes. 

Their results show that it follows a geographically non-stationary process in which the influencing environmental factors have different weights depending on the spatial location. 

This implies that SOC stock modelling should not rely on a single model but on a combination of different statistical models depending on the environmental characteristics of each area. 

Differences in climate, soil pH, content of coarse fragments or land cover type are the main factors exp…

20170915

Author :   Xiaolin Dou, Xiaoli Cheng, Ping He, Ping Zhu, Wei Zhou, Ligang Wang

Year :  2017

Title : 
Dynamics of physically- separated soil organic carbon pools assessed from
δ13C changes under 25 years of cropping systems

Journal : 
Soil & Tillage Research

Comment

They combined soil fractionation with C isotope analyses to investigate the SOC dynamics of the various soil fractions in a black soil of Northeast China after 25 years of tillage.

Soil samples from the initial condition (CK) and 2 cropping treatments including continuous
maize cropping (MM), maize–soybean rotation (MS) were separated into 4 aggregate sizes (< 53 μm,

250–53 μm, 2000–250 μm, and >2000 μm).

The MS system was more beneficial for the SOC accumulation in macroaggregates (> 250 μm) than the MM system because of enhanced SOC in heavier fractions (iPOM and mSOM); this was probably induced by the differentiation of the belowground humification rate between soybean and maize roots, while the MM system may be a more …