Plant–Soil Feedbacks and Temporal Dynamics of Plant Diversity–Productivity Relationships

Our study, which was conducted in the desert grassland of Ningxia in China (E 107.285, N 37.763), involved an experiment with five levels of annual precipitation 33% (R33), 66% (R66), 100% (CK), 133% (R133), 166% (R166) and two temperature levels (inside Open-Top Chamber (OTC) and outside OTC). Our objective was to determine how plant, soil bacteria, and fungi diversity respond to climate change. Our study suggested that plant α-diversity in CK and TCK were significantly higher than that of other treatments. Increased precipitation promoted root biomass (RB) growth more than aboveground living biomass (ALB). R166 promoted the biomass of Agropyron mongolicum the most. In the fungi communities, temperature and precipitation interaction promoted α-diversity. In the fungi communities, the combination of increased temperature and natural precipitation (TCK) promoted β-diversity the most, whose distance was determined to be 25,124 according to PCA. In the bacteria communities, β-diversity in CK was significantly higher than in other treatments, and the distance was determined to be 3010 according to PCA. Soil bacteria and fungi α- and β-diversity, and ALB promoted plant diversity the most. The interactive effects of temperature and precipitation on C, N, and P contents of plants were larger than their independent effects.

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Diel variations in the carbon isotope composition of respired CO<sub>2</sub> and associated carbon sources: a review of dynamics and mechanisms

Biogeosciences Discussions ◽

10.5194/bgd-8-2183-2011 ◽

2011 ◽

Vol 8 (2) ◽

pp. 2183-2233 ◽

Cited By ~ 6

Author(s):

C. Werner ◽

A. Gessler

Keyword(s):

Carbon Isotope ◽

Temporal Dynamics ◽

Carbon Allocation ◽

Ecosystem Respiration ◽

Isotope Composition ◽

Carbon Sources ◽

Mechanistic Explanation ◽

Short Term ◽

Theoretical Understanding ◽

Plant Soil

Abstract. Recent advances have improved our methodological approaches and theoretical understanding of post-photosynthetic carbon isotope fractionation. Nevertheless we still lack a clear picture of the origin of short-term variability in δ13C of respired CO2 (δ13Cres) and organic carbon fractions on a diel basis. However, closing this knowledge gap is essential for the application of stable isotope approaches for partitioning ecosystem respiration, tracing carbon flow through plants and ecosystems and disentangling key physiological processes in carbon metabolism of plants. In this review we examine the short-term dynamics in δ13Cres and putative substrate pools at the plant, soil and ecosystem scales and develop mechanistic explanations for diel δ13Cres dynamics at each scale. Maximum reported variation in diel δ13Cres is 4.0, 5.4 and 14.8‰ in trunks, roots and leaves of different species and 12.5 and 8.1‰ at the soil and ecosystem scale in different biomes. Temporal variation in post-photosynthetic fractionation related to changes in carbon allocation to different metabolic pathways is the most plausible mechanistic explanation for observed diel dynamics in δ13Cres. In addition, mixing of component fluxes with different temporal dynamics and isotopic compositions add to the δ13Cres variation on the soil and ecosystem level. Understanding short-term variations in δ13Cres is particularly important for ecosystem studies, since δ13Cres contains information on the fate of respiratory substrates, and may, therefore, provide a non-intrusive way to identify changes in carbon allocation patterns.

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Multidecadal shifts in forest plant diversity and community composition across glacial landforms in northern lower Michigan, USA

Canadian Journal of Forest Research ◽

10.1139/cjfr-2019-0138 ◽

2020 ◽

Vol 50 (2) ◽

pp. 126-135

Author(s):

Raleigh D. Ricart ◽

Douglas R. Pearsall ◽

Peter S. Curtis

Keyword(s):

Community Composition ◽

Plant Diversity ◽

Temporal Dynamics ◽

Future Climate Change ◽

Spatial And Temporal Patterns ◽

Ecosystem Responses ◽

Community Assemblage ◽

Local Plant ◽

The University ◽

Glacial Landforms

Understanding how plant community assemblage is affected by spatial and temporal patterns is crucial to understanding forest ecosystem responses to disturbance, including future climate change. In this article, we tracked how diversity and composition are distributed through space and time in a midsuccessional mixed hardwood forest in northern lower Michigan, United States. This region’s geographically and abiotically distinct glacial landforms influence both the spatial and temporal dynamics of its forest communities. Vegetation sampling plots (n = 87) were established at the University of Michigan Biological Station in 1990 and resampled in 2015. Vegetation in the overstory, sapling, and groundcover layers was censused. Abiotic variables, including elevation, pH, and soil nutrients, were measured in a subset of plots (n = 40). There were strong differences in diversity and community composition among glacial landforms, with the moraine having a 31% greater species richness in the groundcover layer compared with those of the other glacial landforms. Surprisingly, plant communities across all three vegetation layers showed little change over the 25-year period, and we found no evidence of differences in successional rates among glacial landforms. Our findings indicate that glacial landforms have a large influence on the production and maintenance of local plant diversity and community composition in this area and suggest that successional dynamics may manifest themselves over much longer time periods in these northern biomes.

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