scholarly journals Understory Species Identity Rather than Species Richness Influences Fine Root Decomposition in a Temperate Plantation

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1091
Author(s):  
Rim Khlifa ◽  
Denis A. Angers ◽  
Alison D. Munson
Keyword(s):  
Species Richness ◽  
Fine Root ◽  
Vegetation Succession ◽  
Understory Vegetation ◽  
Root Decomposition ◽  
Species Identity ◽  
Understory Species ◽  
Vegetation Control ◽  
Silvicultural Treatments ◽  
Fine Root Decomposition

Different silvicultural treatments that are applied at plantation establishment may drive different vegetation succession pathways. These divergent vegetation types subsequently feed back to influence soil carbon and nitrogen cycles. One potential mechanism of feedback is through litter decomposition, and in particular fine root decomposition (FRD; <2 mm roots). In the present study we investigated how blade scarification, fertilization, and vegetation control influenced over- and understory vegetation 27 years after plantation, and whether these different vegetation communities affected FRD. In a design using factorial combinations of the three treatments at the Petawawa Research Forest (Laurentian Hills, ON, Canada), we conducted an in situ FRD experiment, with fine roots from the entire vegetation community (both over- and understory) of each plot. The different silvicultural treatments affected overstory basal area, understory species richness and FRD. No correlation was noted between understory species richness and FRD. Instead, we found that understory vegetation (especially fern and herb) cover best explained FRD. We conclude that silvicultural treatments affect FRD through subsequent vegetation succession and that this effect is more likely due to species-specific effects inducing a favorable soil environment than to a higher species richness per se.

scholarly journals Heterogeneity in Decomposition Rates and Nutrient Release in Fine-Root Architecture of Pinus massoniana in the Three Gorges Reservoir Area

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 14
Author(s):  
Shao Yang ◽  
Ruimei Cheng ◽  
Wenfa Xiao ◽  
Yafei Shen ◽  
Lijun Wang ◽  
...  
Keyword(s):  
Lower Order ◽  
Fine Root ◽  
C:N Ratio ◽  
Pinus Massoniana ◽  
Higher Order ◽  
Root Decomposition ◽  
Decomposition Rates ◽  
N Release ◽  
Residual N ◽  
Fine Root Decomposition

Fine-root decomposition contributes a substantial amount of nitrogen that sustains both plant productivity and soil metabolism, given the high turnover rates and short root life spans of fine roots. Fine-root decomposition and soil carbon and nitrogen cycling were investigated in a 1-year field litterbag study on lower-order roots (1–2 and 3–4) of Pinus massoniana to understand the mechanisms of heterogeneity in decomposition rates and further provide a scientific basis for short-time research on fine-root decomposition and nutrient cycling. Lower-order roots had slower decay rates compared with higher-order roots (5–6). A significantly negative correlation was observed between the decay constant mass remaining and initial N concentrations as well as acid unhydrolyzable residues. Results also showed that in lower-order roots (orders 1–2 and 3–4) with a lower C:N ratio, root residual N was released and then immobilized, whereas in higher-order roots (order 5–6) with a higher C:N ratio, root residual N was immobilized and then released in the initial stage. In the later stage, N immobilization occurred in lower-order roots and N release in higher-order roots, with the C:N ratio gradually decreasing to about 40 in three branching-order classes and then increasing. Our results suggest that lower-order roots decompose more slowly than higher-order roots, which may result from the combined effects of high initial N concentration and poor C quality in lower-order roots. During the decomposition of P. massoniana, N release or N immobilization occurred at the critical C:N ratio.

scholarly journals Understory Vegetation Richness and Diversity of Eucalyptus benthamii and Pinus elliottii Plantations in the Midsouth US

2019 ◽  
Author(s):  
Andrea De Stefano ◽  
Michael A Blazier ◽  
Christopher E Comer ◽  
Thomas J Dean ◽  
T Bently Wigley
Keyword(s):  
United States ◽  
Species Richness ◽  
Soil Ph ◽  
Pinus Elliottii ◽  
The United States ◽  
Slash Pine ◽  
Understory Vegetation ◽  
Understory Species ◽  
Species Richness And Diversity ◽  
The Impact

Abstract In the Western Gulf region of the United States cold-tolerant eucalyptus have been explored as pulpwood feedstock. However, non-native plantations may alter understory species diversity, modifying environmental conditions and soil characteristics. Few studies have compared eucalyptus plantations with native ecosystems to understand the impact on understory vegetation in the United States. In this study, we compared understory plant species richness and diversity during 2014–2016 in (1) slash pine (Pinus elliottii) established in 2008, (2) slash pine established in 2013, and (3) and Camden white gum (Eucalyptus benthamii) established in 2013. Overstory characteristics, soil pH, and soil nutrient concentrations were measured to understand factors that affected understory species richness and diversity. Results indicated a decline in understory species richness over time, with Camden white gum in an intermediate condition between same-age slash pine (highest richness) and older slash pine (lowest richness). Leaf area index, soil pH and K, and tree height were the most important factors influencing understory species richness and diversity. The adoption of fast-growing eucalyptus on these sites will probably accelerate the deterioration of natural habitats and reduce open-condition species in favor of shade-tolerant species, overturning the conservation efforts already put in place by governmental agencies and conservation groups.

scholarly journals Global patterns in fine root decomposition: climate, chemistry, mycorrhizal association and woodiness

2019 ◽  
Vol 22 (6) ◽  
pp. 946-953 ◽  
Author(s):  
Craig R. See ◽  
Michael Luke McCormack ◽  
Sarah E. Hobbie ◽  
Habacuc Flores‐Moreno ◽  
Whendee L. Silver ◽  
...  
Keyword(s):  
Fine Root ◽  
Root Decomposition ◽  
Mycorrhizal Association ◽  
Global Patterns ◽  
Fine Root Decomposition

Fine root decomposition, nutrient mobilization and fungal communities in a pine forest ecosystem

2015 ◽  
Vol 83 ◽  
pp. 76-83 ◽  
Author(s):  
Ang Li ◽  
Timothy J. Fahey ◽  
Teresa E. Pawlowska ◽  
Melany C. Fisk ◽  
James Burtis
Keyword(s):  
Forest Ecosystem ◽  
Fine Root ◽  
Pine Forest ◽  
Fungal Communities ◽  
Root Decomposition ◽  
Nutrient Mobilization ◽  
Fine Root Decomposition

Effects of phosphorus addition on fine root decomposition and enzyme activity of Castanopsis carlesii and Cunninghamia lanceolata in subtropical forest

2017 ◽  
Vol 37 (1) ◽  
Author(s):  
洪慧滨 HONG Huibin ◽  
林成芳 LIN Chengfang ◽  
彭建勤 PENG Jianqin ◽  
陈岳民 CHEN Yuemin ◽  
魏翠翠 WEI Cuicui ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Fine Root ◽  
Subtropical Forest ◽  
Cunninghamia Lanceolata ◽  
Root Decomposition ◽  
Phosphorus Addition ◽  
Fine Root Decomposition

Direct and indirect effects of nitrogen additions on fine root decomposition in a subtropical bamboo forest

2014 ◽  
Vol 389 (1-2) ◽  
pp. 273-288 ◽  
Author(s):  
Li-hua Tu ◽  
Yong Peng ◽  
Gang Chen ◽  
Hong-ling Hu ◽  
Yin-long Xiao ◽  
...  
Keyword(s):  
Indirect Effects ◽  
Fine Root ◽  
Root Decomposition ◽  
Bamboo Forest ◽  
Direct And Indirect Effects ◽  
Fine Root Decomposition ◽  
Nitrogen Additions

scholarly journals Effect of Root and Mycelia on Fine Root Decomposition and Release of Carbon and Nitrogen Under Artemisia halodendron in a Semi-arid Sandy Grassland in China

2021 ◽  
Vol 12 ◽  
Author(s):  
Xinping Liu ◽  
Yongqing Luo ◽  
Li Cheng ◽  
Hongjiao Hu ◽  
Youhan Wang ◽  
...  
Keyword(s):  
Fine Roots ◽  
Fine Root ◽  
Organic N ◽  
Root Turnover ◽  
Root Decomposition ◽  
Soil System ◽  
Nitrate N ◽  
Artemisia Halodendron ◽  
Fine Root Decomposition ◽  
Semi Arid

Plant fine root turnover is a continuous process both spatially and temporally, and fine root decomposition is affected by many biotic and abiotic factors. However, the effect of the living roots and the associated mycorrhizal fungal mycelia on fine root decomposition remains unclear. The objective of this study is to explore the influence of these biotic factors on fine root decomposition in a semi-arid ecosystem. In this study, we investigated the effect of fine roots and mycelia on fine root decomposition of a pioneer shrub (Artemisia halodendron) in Horqin sandy land, northeast China, by the ingrowth core method combined with the litterbag method. Litterbags were installed in cores. Results showed that core a allowed the growth of both fine roots and mycelia (treatment R + M), core b only allowed the growth of mycelia (treatment M), and in core c the fine root and mycelia growth were restricted and only bulk soil was present (treatment S). These findings suggest that the process of root decomposition was significantly affected by the living roots and mycelia, and carbon (C) and nitrogen (N) concentration dynamics during root decomposition differed among treatments. Mycelia significantly stimulated the mass loss and C and N release during root decomposition. Treatment R + M significantly stimulated the accumulation of soil total C, total N, and organic N under litterbags. The mycelia significantly stimulated the accumulation of the inorganic N (ammonium-N and nitrate-N) but the presence of fine roots weakened nitrate-N accumulation. The presence of living roots and associated mycelia strongly affected the process of root decomposition and matter release in the litter-soil system. The results of this study should strengthen the understanding of root-soil interactions.

scholarly journals An improved method for quantifying total fine root decomposition in plantation forests combining measurements of soil coring and minirhizotrons with a mass balance model

2020 ◽  
Vol 40 (10) ◽  
pp. 1466-1473
Author(s):  
Xuefeng Li ◽  
Kevan J Minick ◽  
Tonghua Li ◽  
James C Williamson ◽  
Michael Gavazzi ◽  
...  
Keyword(s):  
Fine Roots ◽  
Root Biomass ◽  
Turnover Rate ◽  
Fine Root ◽  
Fine Root Biomass ◽  
Balance Model ◽  
Root Decomposition ◽  
Mass Balance Model ◽  
Monthly Total ◽  
Fine Root Decomposition

Abstract Accurate measurement of total fine root decomposition (the amount of dead fine roots decomposed per unit soil volume) is essential for constructing a soil carbon budget. However, the ingrowth/soil core-based models are dependent on the assumptions that fine roots in litterbags/intact cores have the same relative decomposition rate as those in intact soils and that fine root growth and death rates remain constant over time, while minirhizotrons cannot quantify the total fine root decomposition. To improve the accuracy of estimates for total fine root decomposition, we propose a new method (balanced hybrid) with two models that integrate measurements of soil coring and minirhizotrons into a mass balance model. Model input parameters were fine root biomass, necromass and turnover rate for Model 1, and fine root biomass, necromass and death rate for Model 2. We tested the balanced hybrid method in a loblolly pine plantation forest in coastal North Carolina, USA. The total decomposition rate of absorptive fine roots (ARs) (a combination of first- and second-order fine roots) using Models 1 and 2 was 107 ± 13 g m−2 year−1 and 129 ± 12 g m−2 year−1, respectively. Monthly total AR decomposition was highest from August to November, which corresponded with the highest monthly total ARs mortality. The ARs imaged by minirhizotrons well represent those growing in intact soils, evident by a significant and positive relationship between the standing biomass and the standing length. The total decomposition estimate in both models was sensitive to changes in fine root biomass, turnover rate and death rate but not to change in necromass. Compared with Model 2, Model 1 can avoid the technical difficulty of deciding dead time of individual fine roots but requires greater time and effort to accurately measure fine root biomass dynamics. The balanced hybrid method is an improved technique for measuring total fine root decomposition in plantation forests in which the estimates are based on empirical data from soil coring and minirhizotrons, moving beyond assumptions of traditional approaches.

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