scholarly journals Caution Is Needed in Quantifying Terrestrial Biomass Responses to Elevated Temperature: Meta-Analyses of Field-Based Experimental Warming Across China

Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 619 ◽  
Author(s):  
Kai Yan ◽  
Shuang Zhang ◽  
Yahuang Luo ◽  
Zhenghong Wang ◽  
Deli Zhai ◽  
...  

Certainty over warming-induced biomass accumulation is essential for addressing climate change. However, no previous meta-analysis has investigated this accumulation across the whole of China; also unclear are the differences between herbaceous and woody species and across plant phylogeny, which are critical for corresponding re-vegetation. We extracted data from 90 field-based experiments to reveal general patterns and driving factors of biomass responses all over China. Based on traditional meta-analyses, a warmer temperature significantly increased above- (10.8%) and below-ground (14.2%) biomass accumulation. With increasing warming duration (WarmD) and plant clade age, both above-ground and below-ground biomass showed significant increases. However, for herbaceous versus woody plants, and the whole community versus its dominant species, responses were not always constant; the combined synergies would affect accumulative response patterns. When considering WarmD as a weight, decreases in total above-ground biomass response magnitude were presented, and the increase in below-ground biomass was no longer significant; notably, significant positive responses remained in tree species. However, if phylogenetic information was included in the calculations, all warming-induced plant biomass increases were not significant. Thus, it is still premature to speculate whether warming induces biomass increases in China; further long-term experiments are needed regarding phylogeny-based responses and interspecies relations, especially regarding woody plants and forests.

2017 ◽  
Vol 13 (12) ◽  
pp. 20170510 ◽  
Author(s):  
Nianxun Xi ◽  
Chunhui Zhang ◽  
Juliette M. G. Bloor

Previous studies have suggested that spatial nutrient heterogeneity promotes plant nutrient capture and growth. However, little is known about how spatial nutrient heterogeneity interacts with key community attributes to affect plant community production. We conducted a meta-analysis to investigate how nitrogen heterogeneity effects vary with species richness and plant density. Effect size was calculated using the natural log of the ratio in plant biomass between heterogeneous and homogeneous conditions. Effect sizes were significantly above zero, reflecting positive effects of spatial nutrient heterogeneity on community production. However, species richness decreased the magnitude of heterogeneity effects on above-ground biomass. The magnitude of heterogeneity effects on below-ground biomass did not vary with species richness. Moreover, we detected no modification in heterogeneity effects with plant density. Our results highlight the importance of species richness for ecosystem function. Asynchrony between above- and below-ground responses to spatial nutrient heterogeneity and species richness could have significant implications for biotic interactions and biogeochemical cycling in the long term.


2015 ◽  
Vol 12 (3) ◽  
pp. 757-767 ◽  
Author(s):  
C. Xiao ◽  
I. A. Janssens ◽  
Y. Zhou ◽  
J. Su ◽  
Y. Liang ◽  
...  

Abstract. Global climate change has generally modified net primary production (NPP) which leads to increasing litter inputs in some ecosystems. Therefore, assessing the impacts of increasing litter inputs on soil nutrients, plant growth and ecological carbon (C) : nitrogen (N) : phosphorus (P) stoichiometry is critical for an understanding of C, N and P cycling and their feedback processes to climate change. In this study, we added plant above-ground litter, harvested near the experimental plots, to the 10–20 cm subsoil layer of a steppe community at rates equivalent to annual litter input of 0, 15, 30, 60 and 120%, respectively, covering the entire range of the expected NPP increases in this region due to climate change (10–60%). We measured the resulting C, N and P content of different pools (above- and below-ground plant biomass, litter, microbial biomass). Small litter additions, which are more plausible compared to the expected increase predicted by Earth system models, had no effect on the variables examined. Nevertheless, high litter addition (120% of the annual litter inputs) significantly increased soil inorganic N and available P, above-ground biomass, below-ground biomass and litter. Our results suggest that while very high litter addition can strongly affect C : N : P stoichiometry, the grassland studied here is resilient to more plausible inputs in terms of stoichiometric functioning.


2020 ◽  
Author(s):  
Sophie Drexler ◽  
Axel Don

<p>The establishment of hedgerows as traditional form of agroforestry in Europe is a promising strategy to promote carbon sinks in the context of climate change mitigation. However, only few studies quantified the potential of hedgerows to sequester and store carbon. We therefore conducted a meta-analysis to gain a quantitative overview about the carbon storage in the above- and below-ground biomass and soils of hedgerows.</p><p>Soil organic carbon (SOC) data of hedgerows and adjacent agricultural fields of nine studies with 83 hedgerow sites was compiled. On average, the establishment of hedgerows on cropland increased SOC by 32%. No significant differences were found between the SOC storage of hedgerows and that of grassland. The literature survey on the biomass carbon stocks of hedgerows resulted in 23 sampled hedgerows, which were supplemented by own biomass data of 49 hedgerows from northern Germany. Biomass stocks increased with time since last coppicing and hedgerow height. The mean (± SD) above-ground biomass carbon stock of the analysed hedgerows was 48 ± 29 Mg C ha<sup>-1</sup>. Below-ground biomass values seemed mostly underestimated, as they were calculated from above-ground biomass via fixed assumed root:shoot ratios not specific for hedgerows. Only one study reported measured root biomass under hedgerows with a root:shoot ratio of 0.94:1 ± 0.084. With this shoot:root ratio an average below-ground biomass carbon stock of 45 ± 28 Mg C ha<sup>-1 </sup>was estimated, but with high uncertainty.</p><p>Thus, the establishment of hedgerows on cropland could lead to a SOC sequestration of 1.0 Mg C ha<sup>-1</sup> year<sup>-1</sup> over a 20-year period. Additionally, up to 9.4 Mg C ha<sup>-1</sup> year<sup>-1</sup> could be sequestered in the hedgerow biomass over a 10 year period. In total, hedgerows store 106 ± 41 Mg C ha<sup>-1</sup> more C than croplands. Our results indicate that organic carbon stored in hedgerows is similar high as in forests. We discuss how the establishment of hedgerows, especially on cropland, can thus be an effective option for C sequestration in agricultural landscapes, meanwhile enhance biodiversity, and soil protection.</p>


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
JAMES G. KAIRO ◽  
MICHAEL NJOROGE GITHAIGA ◽  
KIPLAGAT KOTUT ◽  
FRANCIS KARIUKI

Abstract. Githaiga MN, Kotut K, Kariuki F, Kairo JG. 2019. Structure and biomass accumulation of natural mangrove forest at Gazi Bay, Kenya. Bonorowo Wetlands 9: 18-32. The goal of this study was to determine the forest structure and estimate biomass accumulation above and below ground in the mangrove forest of Gazi Bay. The western, middle, and eastern forest blocks of the Gazi Bay mangrove forest were investigated for forest structure, whereas the western forest block was determined for biomass accumulation. To calculate below-ground biomass accumulation, in-growth cores of 80 cm long, 20 cm broad, and 60 cm deep were employed. Above-ground biomass accumulation was calculated using data on tree height and stem diameter at breast height (DBH-130). Leaf phenology was observed by tagging shoots. At the start, environmental variables were measured every four months for a year across four mangrove species zones. The linear regeneration sampling approach was used to determine the composition and distribution pattern of natural regeneration (LRS). Salinity revealed a strong negative connection with above-ground biomass accumulation among the soil environment characteristics studied. Sonneratia alba had the highest biomass accretion rate of 10.5 1.9 t ha-1 yr-1 among the four forest zones. Rhizophora mucronata (8.5 0.8 t ha-1 yr-1), Avicennia marina (5.2 1.8 t ha-1 yr-1), and Ceriops tagal (2.6 1.5 t ha-1 yr-1) were the next most abundant species. Above-ground and below-ground biomass accumulation differed significantly among zones (F (3, 8) = 5.42, p = 0.025) and (F (3, 8) = 16.03, p = 0 001), respectively. There was a significant difference in total biomass accumulation across zones (F (3, 8) =15.56, p = 0.001). For the entire forest, a root : shoot biomass accumulation ratio of 2 : 5 was calculated. This study's findings provide more accurate estimates of mangrove carbon capture and storage, which can be used in carbon credit discussions in the emerging carbon market.


2015 ◽  
Vol 16 (1) ◽  
pp. 42
Author(s):  
Ali Munawar ◽  
Wiryono Wiryono

Revegetation is an important part of reclamation activities of mined land, partly due to potential CO2 absorption from theatmosphere, particularly through photosynthetic reactions. This research was aimed to calculate the amount of C absorbedby two major fast growing legume species in most reclaimed mined lands in Indonesia, mangium (Acacia mangium) andalbizia (Paraserianthes falcataria) at four years of age. Three tree samples of each species were destructively taken fromthe reclaimed mined land belong to PT Bukit Asam (PERSERO) Tbk, Tanjung Enim, South Sumatra to obtain plant biomassproduction of both above and below ground. The above ground plant biomass was separated into leaf, branches & twigs,and stem. All these components and the below ground biomass (roots) were then weighed for fresh weight determination.About 200 g of these tree components were dried in an oven at 70oC to obtain their dry weights, and then ground into 60mesh diameter for C analysis using wet destruction method of Walkley and Black. The results showed that up to the fourthyear, mangium sequestered C almost double of that sequestered by sengon stands, 21.66 and 10.35 kg C/tree respectively.


2010 ◽  
Vol 18 (NA) ◽  
pp. 355-367 ◽  
Author(s):  
Elena L. Zvereva ◽  
Marja Roitto ◽  
Mikhail V. Kozlov

Identification of factors explaining diversity in plant responses to industrial pollution is crucial for predicting fates of polluted ecosystems. Meta-analysis based on 203 publications demonstrated that plants growing near point polluters showed similar decreases in characters reflecting growth (–13.1%) and reproduction processes (–8.5%). In herbaceous plants, root growth was reduced, while aboveground biomass did not change, because the decrease in leaf size was compensated by an increase in leaf number. In contrast, woody plants demonstrated no changes in allometry and their growth was reduced to a greater extent than growth of herbaceous plants. Raunkiaer’s classification of life forms appeared the best predictor of species’ responses to pollution. Within woody plants, trees and shrubs, but not dwarf shrubs, showed strong decreases in growth and reproduction. Within herbaceous plants, significant growth reduction was observed only in annuals. Longevity of foliage or plant phylogeny did not explain variation in species’ responses. Adverse effects of pollution were stronger in regions with higher temperature and precipitation, hinting that existing pollution loads may become more harmful for plants as climate changes. Relatively minor explanatory value of the characteristics of individual polluters removes one of the principal obstacles to accounting for the effects of pollution in vegetation models and allows extrapolation of the effects observed near point polluters to both regional and global scales. We conclude that losses in productivity of plant communities due to aerial pollution can be approximately estimated on the basis of the life form spectra and climate.


2021 ◽  
Author(s):  
Huiying Liu ◽  
Hao Wang ◽  
Nan Li ◽  
Junjiong Shao ◽  
Xuhui Zhou ◽  
...  

Abstract Climate warming is changing above-ground phenology of plants around the world1, 2. However, warming effects on below-ground phenology of plants are unclear despite that roots play a vital role in carbon cycling3. By conducting a global meta-analysis, we show a phenological mismatch between above- and below-ground plant responses to climate warming. Herbaceous plants advanced both the start and end of the growing season based on their above-ground responses, resulting into a shorter growing season. Below-ground phenophases did not exhibit any obvious changes in herbaceous plants. In contrast, climate warming did not affect the length of above-ground growing season but extended the below-ground growing season of woody plants. These results highlight that climate warming can differentially affect above- and below-ground plant phenology with mismatches arising in herbaceous plants via less responsive below-ground phenology whereas mismatches in woody plants via more responsive below-ground phenology. Mismatches in above- and below-ground plant phenology imply that terrestrial carbon cycling models exclusively based on above-ground responses are less accurate, which highlight the urgent need to incorporate below-ground plant phenology into future Earth system models.


2019 ◽  
Vol 11 (9) ◽  
pp. 2711 ◽  
Author(s):  
Ahmed Mahmoud Abbas ◽  
Sameh K. Abd-Elmabod ◽  
Soad M. El-Ashry ◽  
Wagdi Saber Soliman ◽  
Noha El-Tayeh ◽  
...  

Sewage sludge improves agricultural soil and plant growth, but there are hazards associated with its use, including high metal(loid) contents. An experimental study was conducted under greenhouse conditions to examine the effects of sewage sludge on growth of the invasive tree Prosopis glandulosa, as well as to determine its phytoremediation capacity. Plants were established and grown for seven months along a gradient of sewage sludge content. Plant traits, soil properties, and plant and soil concentrations of N, P, K, Cd, Pb, Cu, Ni, Zn, Cr, Co, As, and Fe were recorded. The addition of sewage sludge led to a significant decrease in soil pH, and Ni, Co, and As concentrations, as well as an increase in soil organic matter and the concentrations of N, P, Cu, Zn, and Cr. Increasing sewage sludge content in the growth medium raised the total uptake of most metals by P. glandulosa plants due to higher biomass accumulation (taller plants with more leaves) and higher metal concentrations in the plant tissues. P. glandulosa concentrated more Cd, Pb, Cu, Zn, and Fe in its below-ground biomass (BGB) than in its above-ground biomass (AGB). P. glandulosa concentrated Ni, Co, and As in both BGB and AGB. P. glandulosa has potential as a biotool for the phytoremediation of sewage sludges and sewage-amended soils in arid and semi-arid environments, with a potential accumulation capability for As in plant leaves.


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