Effects of root exudates of woody species on the soil anti-erodibility in the rhizosphere in a karst region, China

10.7287/peerj.preprints.2624v2 ◽

2017 ◽

Author(s):

Zhenhong Wang ◽

Hong Fang ◽

Mouhui Chen

Keyword(s):

Organic Matter ◽

Root Exudates ◽

Woody Species ◽

Interspecific Variation ◽

Root Density ◽

Karst Region ◽

Interspecific Differences ◽

The Stability ◽

Term Maintenance

Introduction: Rhizospheres, the most active interfaces between plants and soils, play a central role in a long-term maintenance of the biosphere. The anti-erodibility of soils (AES) regulated by the root exudates is crucial to the stability of the rhizospheres. However, scientists still remain unclear regarding the key organic matter in the root exudates to affect the AES and interspecific variation. Methods: We used an incubation of soils to test the effects of the root exudates from 8 woody plant species on a change in soil aggregation, and identified the organic matter in these root exudates with gas chromatograph-mass spectrometer (GC-MS) and biochemical methods. Furthermore, the relationships between the organic matter in the exudates and the AES in the rhizosperes of the 34 additional tree species were analyzed. Results: The water-stable aggregates of the soils incubated with the root exudates increased by 15-50% on average compared with controls, and the interspecific differences were significant. The root exudates included hundreds of specific organic matter, in which hydrocarbon, total sugar, total amino acids and phenolic compounds were crucial to the AES. These types of the matter could explain about 20-75% of the variation in total effects of the root exudates on the AES quantified by aggregate status, degree of aggregation, dispersion ratio and dispersion coefficient. Discussion: Effects of the root exudates on the AES and the interspecific variation are as important as those of root density, litters and vegetation covers. A range of studies have explored the effects of root density, litters, vegetation covers and types on the AES, but little attention has been given to the effects of the root exudates on the AES. Different plants secrete the different relative contents of the organic matter resulting in the variation of the effects of the root exudates on the AES. Our study quantified the causal relationships between the root exudates and the AES from modeling experiments in laboratory to actual effects in the field, and indicated the interspecific variation of the AES and the organic matter in the root exudates. Conclusions: The study recognized more organic compounds in the exudates related to the AES. These results can enhance the understanding of the stability of the soils in a slope and be applied to ecosystem restoration.

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Effects of root exudates of woody species on the soil anti-erodibility in the rhizosphere in a karst region, China

10.7287/peerj.preprints.2624v1 ◽

2016 ◽

Author(s):

Zhen Hong Wang ◽

Hong Fang ◽

Mouhui Chen

Keyword(s):

Organic Matter ◽

Root Exudates ◽

Woody Species ◽

Interspecific Variation ◽

Root Density ◽

Karst Region ◽

Interspecific Differences ◽

The Stability ◽

Term Maintenance

Introduction: The rhizospheres, the most active interfaces between plants and soils, play a central role in a long-term maintenance of the biosphere. The anti-erodibility of soils (AES) regulated by the root exudates is crucial to the stability of the rhizospheres. However, scientists still remain unclear regarding the key organic matter in the root exudates to affect the AES and interspecific variation. Methods: We used an incubation of soils to test the effects of the root exudates from 8 woody plant species on a change in soil aggregation, and identified the organic matter in these root exudates with gas chromatograph-mass spectrometer (GC-MS) and biochemical methods. Furthermore, the relationships between the organic matter in the exudates and the AES in the rhizosperes of the 34 additional tree species were analyzed. Results: The water-stable aggregates of the soils incubated with the root exudates increased by 15-50% on average compared with controls, and the interspecific differences were significant. The root exudates included hundreds of specific organic matter, in which hydrocarbon, total sugar, total amino acids and phenolic compounds were crucial to the AES. These types of the matter could explain about 20-75% of the variation in total effects of the root exudates on the AES quantified by aggregate status, degree of aggregation, dispersion ratio and dispersion coefficient. Discussion: Effects of the root exudates on the AES and the interspecific variation are as important as those of root density, litters and vegetation covers. A range of studies have explored the effects of root density, litters, vegetation covers and types on the AES, but little attention has been given to the effects of the root exudates on the AES. Different plants secrete the different relative contents of the organic matter resulting in the variation of the effects of the root exudates on the AES. Our study quantified the causal relationships between the root exudates and the AES from modeling experiments in laboratory to actual effects in the field, and indicated the interspecific variation of the AES and the organic matter in the root exudates. Conclusions: The study recognized more organic compounds in the exudates related to the AES. These results can enhance the understanding of the stability of the soils in a slope and be applied to ecosystem restoration.

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Effects of root exudates of woody species on the soil anti-erodibility in the rhizosphere in a karst region, China

PeerJ ◽

10.7717/peerj.3029 ◽

2017 ◽

Vol 5 ◽

pp. e3029 ◽

Cited By ~ 8

Author(s):

Zhen Hong Wang ◽

Hong Fang ◽

Mouhui Chen

Keyword(s):

Organic Matter ◽

Root Exudates ◽

Woody Species ◽

Interspecific Variation ◽

Root Density ◽

Gas Chromatography Mass Spectrometry ◽

Karst Region ◽

Soil Stability ◽

Interspecific Differences

IntroductionRhizospheres, the most active interfaces between plants and soils, play a central role in the long-term maintenance of the biosphere. The anti-erodibility of soils (AES) regulated by the root exudates is crucial to the soil stability in the rhizospheres. However, scientists still debate (1) the key organic matter of the root exudates affecting the AES and (2) the interspecific variation of these root exudates.MethodsWe used an incubation of soils to test the effects of the root exudates from eight woody plant species on the change in soil aggregation and identified the organic matter in these root exudates with gas chromatography-mass spectrometry (GC-MS) and biochemical methods. Furthermore, the relationships between the organic matter in the exudates and the AES in the rhizospheres of 34 additional tree species were analyzed.ResultsThe water-stable aggregates of the soils incubated with the root exudates increased by 15%–50% on average compared with control samples. The interspecific differences were significant. The root exudates included hundreds of specific organic matter types; hydrocarbon, total sugar, total amino acids, and phenolic compounds were crucial to the AES. These organic matter types could explain approximately 20–75% of the variation in the total effect of the root exudates on the AES, which was quantified based on the aggregate status, degree of aggregation, dispersion ratio, and dispersion coefficient.DiscussionThe effects of the root exudates on the AES and the interspecific variation are as important as that of root density, litters, and vegetation covers. Many studies explored the effects of root density, litters, vegetation covers, and vegetation types on the AES, but little attention has been paid to the effects of the root exudates on the AES. Different plants secrete different relative contents of organic matter resulting in the variation of the effect of the root exudates on the AES. Our study quantified the causal relationships between the root exudates and the AES using modeling experiments in laboratory and field observations and indicated the interspecific variation of the AES and organic matter of the root exudates.ConclusionsMore organic compounds of the exudates related to the AES were recognized in this study. These results enhance the understanding of the soil stability at a slope and can be applied to ecosystem restoration.

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A versatile thermal gradient apparatus for studying thermal biology of snakes in the laboratory

Canadian Journal of Zoology ◽

10.1139/z82-435 ◽

1982 ◽

Vol 60 (12) ◽

pp. 3456-3459 ◽

Cited By ~ 3

Author(s):

Patrick T. Gregory ◽

Robert J. Douwens ◽

A. G. Duncan McIntosh

Keyword(s):

Thermal Gradient ◽

Garter Snakes ◽

Thermal Biology ◽

Temperature Selection ◽

Interspecific Differences ◽

Selection Experiments ◽

Degree Of Control ◽

High Degree ◽

Term Maintenance

We present a design for a thermal gradient apparatus which allows long-term maintenance of temperature gradients which can be varied in position and in range from extremely wide to extremely narrow. The apparatus can also be used simply as a series of controlled-temperature chambers. A high degree of control of temperature along the gradient is possible. Preliminary temperature-selection experiments with garter snakes yielded results consistent with interspecific differences observed in the field.

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Peer Review #2 of "Effects of root exudates of woody species on the soil anti-erodibility in the rhizosphere in a karst region, China (v0.2)"

10.7287/peerj.3029v0.2/reviews/2 ◽

2017 ◽

Keyword(s):

Peer Review ◽

Root Exudates ◽

Woody Species ◽

Karst Region

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Establishment of a cryopreserved biobank for the Culture Collection of Freshwater Microalgae (CCMA-UFSCar), São Paulo, Brazil

Biota Neotropica ◽

10.1590/1676-0611-bn-2016-0299 ◽

2017 ◽

Vol 17 (2) ◽

Cited By ~ 1

Author(s):

Leticia Piton Tessarolli ◽

John Godfrey Day ◽

Armando Augusto Henriques Vieira

Keyword(s):

Green Algae ◽

Biological Materials ◽

Culture Collection ◽

Freshwater Microalgae ◽

The Past ◽

The Stability ◽

Taxonomic Groups ◽

And Training ◽

Term Maintenance

Abstract The Culture Collection of Freshwater Microalgae (CCMA-UFSCar, Coleção de Culturas de Microalgas de Água-Doce), based at the Universidade Federal de São Carlos, plays an important role in underpinning Brazilian microalgal research, providing biological materials, substrates and training personnel for a large proportion of the past and current projects in this area. However, recent efforts to expand the culture catalogue/holdings have reached a ceiling because of the logistical practicality of maintaining actively growing cultures. In order to reduce the costs associated with the maintenance regime of cultures, efforts were initiated on the establishment of a cryopreserved biobank for long term maintenance of cultures, thus minimizing the efforts associated with handling of material, as successfully frozen cultures, in theory, could be maintained effectively indefinitely, with the advantage of the stability of cells characteristics. Initial tests were performed on 93 strains including exemplar taxa across the different taxonomic groups in the collection catalogue. The highest levels of success were achieved for the smaller taxa, such as the small green algae; while for the larger and more complex organisms limited to no success was obtained. For the strains tested, over 70% had positive good levels of post-thaw viability and regenerated phenotypically normal cultures.

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