scholarly journals Variation in Organ Biomass with Changing Climate and Forest Characteristics across Chinese Forests

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 521 ◽  
Author(s):  
Yiran Fang ◽  
Xiaojun Zou ◽  
Zhiyang Lie ◽  
Li Xue
Keyword(s):  
Biomass Allocation ◽  
Resource Availability ◽  
Mass Fraction ◽  
Forest Biomass ◽  
Stand Age ◽  
Forest Types ◽  
Allocation Patterns ◽  
The Impact ◽  
Leaf Mass Fraction ◽  
Global Carbon

Forest biomass allocation patterns are important for understanding global carbon cycling and climate change, which might change with environmental conditions and forest characteristics. However, the effects of climate and forest characteristics on biomass allocation fractions (the fraction of total forest biomass distributed in organs) remains unknown. The authors use a large Chinese biomass dataset (1081 forests encompassing 10 forest types) to analyse the responses of biomass allocation fractions to biogeography, climate, and forest characteristics. The authors found that the stem mass fraction significantly increased with age and precipitation and significantly decreased with latitude and temperature. The branch mass fraction significantly decreased with age and density, but significantly increased with temperature and latitude. The leaf mass fraction significantly decreased with age and precipitation and significantly increased with temperature. The root mass fraction significantly increased with latitude and density, and significantly decreased with precipitation. The results suggest that latitude, temperature, precipitation, stand age and density are good predictors of biomass partitioning. These findings support the hypotheses that variation in resource availability constrains organ allocation and provides biogeographically explicit relationships between biomass allocation and both environmental and forest characteristics, which might be used for assessing the impact of changing environmental and forest characteristics on forest carbon dynamics and fixation.

scholarly journals Multiple Factors Drive Variation of Forest Root Biomass in Southwestern China

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 456 ◽  
Author(s):  
Hao Zhang ◽  
Kelin Wang ◽  
Zhaoxia Zeng ◽  
Zhigang Zou ◽  
Yanfang Xu ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Root Biomass ◽  
Forest Biomass ◽  
Southwestern China ◽  
Stand Age ◽  
Forest Types ◽  
Annual Increment ◽  
Multiple Factors ◽  
Patterns Of Distribution ◽  
Stand Characteristics

The roots linking the above-ground organs and soil are key components for estimating net primary productivity and carbon sequestration of forests. The patterns and drivers of root biomass in forest have not been examined well at the regional scale, especially for the widely distributed forest ecosystems in southwestern China. We attempted to determine the spatial patterns of root biomass (RB, Mg/ha), annual increment root biomass (AIRB, Mg/ha/year), ratio of root and above-ground (RRA), and the relative contributions of abiotic and biotic factors that drive the variation of root biomass. Forest biomass and multiple factors (climate, soil, forest types, and stand characteristics) of 318 plots in this region (790,000 km2) were analyzed in this research. The AB (the mean values for forest aboveground biomass per ha, Mg/ha), RB, AIRB, and RRA were 126 Mg/ha, 28 Mg/ha, 0.69 Mg/ha and 0.22, respectively. AB, RB, AIRB, and RRA varied across all the plots and forest types. Both RB and AIRB showed significant spatial patterns of distribution, while RRA did not show any spatial patterns of distribution. Up to 28.4% of variation in total of RB, AIRB, and RRA can be attributed to the climate, soil, and stand characteristics. The explained or contribution rates of climate, soil, and stand characteristics for variation of whole forest root biomass were 6.7%, 16.9%, and 10.9%, respectively. Path analysis in structural equation model (SEM) indicated the direct influence of stand age on RB. AIRB was greater than that of the other factors. Climate, soil and stand characteristics in different forest types could explain 9.7%–96.1%, 15.4%–96.4%, and 36.7%–99.4% of variations in RB, AIRB, and RRA, respectively, which suggests that the multiple factors may be important in explaining the variations in forest root biomass. The results of the analysis of root biomass per ha, annual increment of root biomass per ha, and ratio of root and above-ground in the seven forest types categorized by climate, soil, and stand characteristics may be used for accurately determining C sequestration by the forest root and estimating forest biomass in this region.

scholarly journals Stand Feature Associating With Climate Seasonality Determinate Root-Shoot Ratios of Forest Ecosystems in China

2020 ◽  
Author(s):  
Feng-Feng Kang ◽  
Ai-Hua Yu ◽  
Mingchun Guo ◽  
Qi Wang ◽  
Ze-Ping Jiang ◽  
...  
Keyword(s):  
Biomass Allocation ◽  
Forest Ecosystems ◽  
Forest Biomass ◽  
Forest Age ◽  
Natural Forests ◽  
Forest Types ◽  
Planted Forests ◽  
Forest Density ◽  
Shoot Ratio ◽  
Root Shoot Ratio

Abstract Background: Forest ecosystems play a crucial role in global carbon cycle. Identifying bio- or abio- drivers on forest biomass allocation pattern could improve our understanding in forest carbon sink, stock and cycle across various spatio-temporal scales. Through compiling a dataset (n=1931) of the root-shoot ratio from previous studies, here we implemented the Random Forest algorithm (RF) to elucidate main driven factors on the root-shoot ratio across China forest ecosystems. Results: (1) Forest age and forest density were both contributed mostly to root-shoot ratio variations regardless of forest origins (natural or planted forests). The relative important values (% increase in MSE) for forest density and forest age on the root-shoot ratio were 54.42% and 51.05% in the natural forests, and 74.61% and 117.27% in the planted forests, respectively; (2) Compared to soil variables (soil texture and nutrient status), climatic variables (temperature and precipitation) showed stronger effects on the root-shoot ratio; (3) Partial dependent analysis further demonstrated that root-shoot ratio initially decreased with forest age, but afterwards increased to a relative stable level (the turning point, e.g., ca. 150 yr for natural forests and ca.30 yr for planted forests); (4)The root-shoot ratio increased nonlinearly with an increase of forest density in both forest types. Forest density and precipitation seasonality exerted positively direct effects, while forest age together with temperature seasonality, mean temperature of wettest quarter and precipitation of warmest quarter had negatively effects on the root-shoot ratio of two forest types. Conclusions: The forest age, forest density and climate seasonality contributed mostly to variations of root-shoot ratios in China forest ecosystems. These results would improve our understanding of environmental drivers on forest biomass allocation over a large spatial scale, and to some extent provide a generally practical significance in forest management (e.g., time for timber harvest), although species-specific root-shoot ratio associated with ontogeny should be further investigated in the future.

scholarly journals Nitrogen addition affects plant biomass allocation but not allometric relationships among different organs across the globe

2020 ◽  
Author(s):  
Kai Yue ◽  
Dario A Fornara ◽  
Wang Li ◽  
Xiangyin Ni ◽  
Yan Peng ◽  
...  
Keyword(s):  
Biomass Allocation ◽  
Mass Fraction ◽  
Plant Biomass ◽  
Terrestrial Ecosystems ◽  
Interactive Effects ◽  
N Addition ◽  
Allometric Relationships ◽  
Optimal Partitioning ◽  
Whole Plant ◽  
Allocation Patterns

Abstract Aims Biomass allocation to different organs is a fundamental plant ecophysiological process to better respond to changing environments; yet, it remains poorly understood how patterns of biomass allocation respond to nitrogen (N) additions across terrestrial ecosystems worldwide. Methods We conducted a meta-analysis using 5474 pairwise observations from 333 articles to assess how N addition affected plant biomass and biomass allocation among different organs. We also tested the “ratio-based optimal partitioning” vs. the “isometric allocation” hypotheses to explain potential N addition effects on biomass allocation. Important findings We found that (1) N addition significantly increased whole plant biomass and the biomass of different organs, but decreased root:shoot ratio (RS) and root mass fraction (RMF) while no effects of N addition on leaf mass fraction (LMF) and stem mass fraction (SMF) at the global scale; (2) the effects of N addition on ratio-based biomass allocation were mediated by individual or interactive effects of moderator variables such as experimental conditions, plant functional types, latitudes, and rates of N addition; and (3) N addition did not affect allometric relationships among different organs, suggesting that decreases in RS and RMF may result from isometric allocation patterns following increases in whole plant biomass. Despite alteration of ratio-based biomass allocation between root and shoot by N addition, the unaffected allometric scaling relationships among different organs (including root vs. shoot) suggest that plant biomass allocation patterns are more appropriately explained by the isometric allocation hypothesis rather than the optimal partitioning hypothesis. Our findings contribute to better understand N-induced effects on allometric relationships of terrestrial plants, and suggest that these ecophysiological responses should be incorporated into models that aim to predict how terrestrial ecosystems may respond to enhanced N deposition under future global change scenarios.

scholarly journals Carbon stock and sink economic values of forest ecosystem in the forest industry region of Heilongjiang Province, China

2021 ◽  
Author(s):  
Mingjuan Li
Keyword(s):  
Forest Ecosystem ◽  
Carbon Stock ◽  
Carbon Sink ◽  
Stand Age ◽  
Cumulative Impact ◽  
Vector Autoregressive ◽  
Factors Affecting ◽  
The Impact ◽  
Global Carbon

AbstractThe values of forest carbon stock (CSV) and carbon sink (COV) are important topics in the global carbon cycle. We quantitatively analyzed the factors affecting changes in both for forest ecosystem in 2000−2015. With multiple linear stepwise regression analysis, we obtained the factors that had a significant impact on changes of CSV and COV, and then the impacts of these variables on CSV and COV were used for further quantitative analysis using the vector autoregressive model. Our results indicated that both stand age and afforestation area positively affect CSV and COV; however, the forest enterprise gross output value negatively affects CSV. Stand age has the largest long-term cumulative impact on CSV and COV, reaching 40.4% and 9.8%, respectively. The impact of enterprise gross output value and afforestation area on CSV and COV is the smallest, reaching 4.0% and 0.3%, respectively.

Measuring Impact of Stress in Sandwich Generation Caring for Demented Parents

GeroPsych ◽  
2014 ◽  
Vol 27 (4) ◽  
pp. 171-179 ◽  
Author(s):  
Laurence M. Solberg ◽  
Lauren B. Solberg ◽  
Emily N. Peterson
Keyword(s):  
Factor Analysis ◽  
Exploratory Factor Analysis ◽  
Social Worker ◽  
Resource Availability ◽  
Well Being ◽  
Sandwich Generation ◽  
Item Questionnaire ◽  
Significant Difference ◽  
Adult Caregivers ◽  
The Impact

Stress in caregivers may affect the healthcare recipients receive. We examined the impact of stress experienced by 45 adult caregivers of their elderly demented parents. The participants completed a 32-item questionnaire about the impact of experienced stress. The questionnaire also asked about interventions that might help to reduce the impact of stress. After exploratory factor analysis, we reduced the 32-item questionnaire to 13 items. Results indicated that caregivers experienced stress, anxiety, and sadness. Also, emotional, but not financial or professional, well-being was significantly impacted. There was no significant difference between the impact of caregiver stress on members from the sandwich generation and those from the nonsandwich generation. Meeting with a social worker for resource availability was identified most frequently as a potentially helpful intervention for coping with the impact of stress.

scholarly journals Impact of Atmospheric Optical Properties on Net Ecosystem Productivity of Peatland in Poland

2021 ◽  
Vol 13 (11) ◽  
pp. 2124
Author(s):  
Kamila M. Harenda ◽  
Mateusz Samson ◽  
Radosław Juszczak ◽  
Krzysztof M. Markowicz ◽  
Iwona S. Stachlewska ◽  
...  
Keyword(s):  
Optical Properties ◽  
Diffuse Radiation ◽  
Co2 Uptake ◽  
High Carbon ◽  
Atmospheric Scattering ◽  
Net Productivity ◽  
Diffusion Index ◽  
Ecosystem Production ◽  
The Impact ◽  
Global Carbon

Peatlands play an important role in the global carbon cycle due to the high carbon storage in the substrate. Ecosystem production depends, for example, on the solar energy amount that reaches the vegetation, however the diffuse component of this flux can substantially increase ecosystem net productivity. This phenomenon is observed in different ecosystems, but the study of the atmosphere optical properties on peatland production is lacking. In this paper, the presented methodology allowed us to disentangle the diffuse radiation impact on the net ecosystem production (NEP) of Rzecin peatland, Poland. It allowed us to assess the impact of the atmospheric scattering process determined by the aerosol presence in the air mass. An application of atmospheric radiation transfer (ART) and ecosystem production (EP) models showed that the increase of aerosol optical thickness from 0.09 to 0.17 caused NEP to rise by 3.4–5.7%. An increase of the diffusion index (DI) by 0.1 resulted in an NEP increase of 6.1–42.3%, while a DI decrease of 0.1 determined an NEP reduction of −49.0 to −10.5%. These results show that low peatland vegetation responds to changes in light scattering. This phenomenon should be taken into account when calculating the global CO2 uptake estimation of such ecosystems.

scholarly journals Seasonal feeding plasticity can facilitate coexistence of dominant omnivores in Neotropical streams

2021 ◽  
Author(s):  
Mayara P. Neves ◽  
Pavel Kratina ◽  
Rosilene L. Delariva ◽  
J. Iwan Jones ◽  
Clarice B. Fialho
Keyword(s):  
Seasonal Variation ◽  
Fish Species ◽  
Resource Availability ◽  
Seasonal Changes ◽  
Dry Season ◽  
Diet Overlap ◽  
Isotopic Niche ◽  
Neotropical Streams ◽  
Feeding Plasticity ◽  
The Impact

AbstractCoexistence of ecomorphologically similar species in diverse Neotropical ecosystems has been a focus of long-term debate among ecologists and evolutionary biologists. Such coexistence can be promoted by trophic plasticity and seasonal changes in omnivorous feeding. We combined stomach content and stable isotope analyses to determine how seasonal variation in resource availability influences the consumption and assimilation of resources by two syntopic fish species, Psalidodon aff. gymnodontus and P. bifasciatus, in the Lower Iguaçu basin. We also tested the impact of seasonality on trophic niche breadth and diet overlap of these two dominant omnivores. Seasonal changes in resource availability strongly influenced the consumption and assimilation of resources by the two fish species. Both species exhibited high levels of omnivory, characterized by high diversity of allochthonous resources in the wet season. Terrestrial invertebrates were the main component of diet during this season. However, in the dry season, both species reduced their isotopic niches, indicating diet specialization. High diet overlap was observed in both seasons, but the isotopic niche overlap was smaller in the dry season. Substantial reduction in the isotopic niche of P. bifascistus and a shift toward aquatic invertebrates can facilitate coexistence during this season of resource shortage. Feeding plasticity allows omnivorous fish to adjust their trophic niches according to seasonality, promoting the exploitation of different resources during periods of greater resource diversity. This seasonal variation could be an important mechanism that contributes to the resource partitioning and coexistence of dominant omnivores in Neotropical streams.

Influence of flour from oilseed meal on sugars content in rye bread

2021 ◽  
Vol 9 (16) ◽  
pp. 57-68
Author(s):  
Halyna Voloshchuk ◽  
Keyword(s):  
Chemical Composition ◽  
Mass Fraction ◽  
Raw Materials ◽  
Sugar Content ◽  
Jerusalem Artichoke ◽  
Oilseed Meal ◽  
Rye Bread ◽  
Rye Flour ◽  
Pumpkin Seeds ◽  
The Impact

Subject of research – sugar content in rye bread with fractionally defatted flour from walnuts, pumpkin seeds, sesame and Jerusalem artichoke powder. The purpose – to investigate the chemical composition of sugars in flour from oilseed meal and to explain the impact of new raw materials upon the sugar content in bread made from rye flour. Materials and methods. For the production of pilot of bread used: rye flour; fermented rye malt; table salt; drinking water; ready liquid rye sourdough (composition: Lactobacillus plantarum 30, L .casei 26, L. fermenti 34, L .brevis and Saccharomyces minor "Chernorichenskaya", S. cerevisiae L1); fractionally defatted flour from walnuts, pumpkin seeds and sesame produced by PE "Research and Production Company "Elitfito"; Jerusalem artichoke powder "Dar". The dough was prepared in a three-phase way: liquid sourdough – saccharified choux – dough. Jerusalem artichoke powder and oilseed meal were added to the dough. The chemical composition of sugars in raw materials and bread was determined by high-performance liquid chromatography. The effect of fractionally defatted flour on the course of processes in rye dough was performed on a farinograph and amylograph of Brabender. The intensity of gas formation of the dough was determined on the device AG-1. Changes in the crystal structure of the bread crumb were performed using X-ray phase analysis on the device DRON UM-1 in the range of angles 2θ from 5 to 60 degrees. Results. It is established that the share of sugars in flour from oilseed meal is 2 ... 8 times higher than the content of sugars in rye flour. The content of sugars in fractionally defatted flour from walnuts is 43.0 %, from pumpkin seeds – 14.2 %, from sesame – 12.8% by weight of dry matter. Up to 80% of all sugars in fractionally defatted flour are sucrose and maltose. The ratio of fructose to glucose in fractionally defatted flour from walnuts is 1:1.25; from pumpkin seeds – 1:0.73; of sesame seeds – 1:0.5. The addition of 7.0 % fractionally defatted flour mixed with 3 % of the Jerusalem artichoke powder reduces the mass fraction of sugars in bread compared to the bread made with Jerusalem artichoke only. It has been studied that fractionally defatted flour from walnuts, pumpkin seeds and sesame reduces the hydrolytic decomposition of rye flour starch and promotes the process of fermentation of sugars. Scope. A mixture of fractionally defatted flour from oilseed meal in the amount of 7 % should be used for the production of bread from rye flour with 3 % Jerusalem artichoke powder to the mass fraction of flour to reduce the content of high glycemic starch sugars.

scholarly journals Investigation of post-depositional processing of nitrate in East Antarctic snow: isotopic constraints on photolytic loss, re-oxidation, and source inputs

2015 ◽  
Vol 15 (16) ◽  
pp. 9435-9453 ◽  
Author(s):  
G. Shi ◽  
A. M. Buffen ◽  
M. G. Hastings ◽  
C. Li ◽  
H. Ma ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Mass Fraction ◽  
Stratospheric Ozone ◽  
Warm Season ◽  
Cold Season ◽  
Depth Interval ◽  
Depositional Processes ◽  
Antarctic Snow ◽  
Exponential Change ◽  
The Impact

Abstract. Snowpits along a traverse from coastal East Antarctica to the summit of the ice sheet (Dome Argus) are used to investigate the post-depositional processing of nitrate (NO3−) in snow. Seven snowpits from sites with accumulation rates between 24 and 172 kg m−2 a−1 were sampled to depths of 150 to 300 cm. At sites from the continental interior (low accumulation, < 55 kg m−2 a−1), nitrate mass fraction is generally > 200 ng g−1 in surface snow and decreases quickly with depth to < 50 ng g−1. Considerably increasing values of δ15N of nitrate are also observed (16–461 ‰ vs. air N2), particularly in the top 20 cm, which is consistent with predicted fractionation constants for the photolysis of nitrate. The δ18O of nitrate (17–84 ‰ vs. VSMOW (Vienna Standard Mean Ocean Water)), on the other hand, decreases with increasing δ15N, suggestive of secondary formation of nitrate in situ (following photolysis) with a low δ18O source. Previous studies have suggested that δ15N and δ18O of nitrate at deeper snow depths should be predictable based upon an exponential change derived near the surface. At deeper depths sampled in this study, however, the relationship between nitrate mass fraction and δ18O changes, with increasing δ18O of nitrate observed between 100 and 200 cm. Predicting the impact of post-depositional loss, and therefore changes in the isotopes with depth, is highly sensitive to the depth interval over which an exponential change is assumed. In the snowpits collected closer to the coast (accumulation > 91 kg m−2 a−1), there are no obvious trends detected with depth and instead seasonality in nitrate mass fraction and isotopic composition is found. In comparison to the interior sites, the coastal pits are lower in δ15N (−15–71 ‰ vs. air N2) and higher in δ18O of nitrate (53–111 ‰ vs. VSMOW). The relationships found amongst mass fraction, δ15N, δ18O and Δ17O (Δ17O = δ17O–0.52 × δ18O) of nitrate cannot be explained by local post-depositional processes alone, and are instead interpreted in the context of a primary atmospheric signal. Consistent with other Antarctic observational and modeling studies, the isotopic results are suggestive of an important influence of stratospheric ozone chemistry on nitrate formation during the cold season and a mix of tropospheric sources and chemistry during the warm season. Overall, the findings in this study speak to the sensitivity of nitrate isotopic composition to post-depositional processing and highlight the strength of combined use of the nitrogen and oxygen isotopes for a mechanistic understanding of this processing.

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