scholarly journals Allometric relations for biomass partitioning of seven alpine Rhododendron species in south of Gansu

2020 ◽  
Vol 44 (10) ◽  
pp. 1040-1049
Author(s):  
Guo-Peng CHEN ◽  
Ke-Tong YANG ◽  
Li WANG ◽  
Fei WANG ◽  
Xiu-Wen CAO ◽  
...  
Keyword(s):  
Biomass Partitioning ◽  
Allometric Relations

scholarly journals Potassium Application Positively Modulates Physiological Responses of Cocoa Seedlings to Drought Stress

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 563
Author(s):  
Esther Anokye ◽  
Samuel T. Lowor ◽  
Jerome A. Dogbatse ◽  
Francis K. Padi
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Chlorophyll Content ◽  
Electrolyte Leakage ◽  
Seedling Survival ◽  
Biomass Accumulation ◽  
Biomass Partitioning ◽  
Chlorophyll Content And Fluorescence ◽  
Physiological Functions ◽  
Soil Water Stress

With increasing frequency and intensity of dry spells in the cocoa production zones of West Africa, strategies for mitigating impact of water stress on cocoa seedling survival are urgently required. We investigated the effects of applied potassium on biomass accumulation, physiological processes and survival of cocoa varieties subjected to water stress in pot experiments in a gauzehouse facility. Four levels of potassium (0, 1, 2, or 3 g/plant as muriate of potash) were used. Soil water stress reduced plant biomass accumulation (shoot and roots), relative water content (RWC), chlorophyll content and fluorescence. Leaf phenol and proline contents were increased under water stress. Additionally, compared to the well-watered conditions, soils under water stress treatments had higher contents of exchangeable potassium and available phosphorus at the end of the experimental period. Potassium applied under well-watered conditions reduced leaf chlorophyll content and fluorescence and increased leaf electrolyte leakage, but improved the growth and integrity of physiological functions under soil water stress. Potassium addition increased biomass partitioning to roots, improved RWC and leaf membrane stability, and significantly improved cocoa seedling survival under water stress. Under water stress, the variety with the highest seedling mortality accumulated the highest contents of phenol and proline. A significant effect of variety on plant physiological functions was observed. Generally, varieties with PA 7 parentage had higher biomass partitioning to roots and better seedling survival under soil moisture stress. Proportion of biomass partitioned to roots, RWC, chlorophyll fluorescence and leaf electrolyte leakage appear to be the most reliable indicators of cocoa seedling tolerance to drought.

scholarly journals Deriving Tree Size Distributions of Tropical Forests from Lidar

2021 ◽  
Vol 13 (1) ◽  
pp. 131
Author(s):  
Franziska Taubert ◽  
Rico Fischer ◽  
Nikolai Knapp ◽  
Andreas Huth
Keyword(s):  
Size Distribution ◽  
Spatial Scales ◽  
Basal Area ◽  
Tree Height ◽  
Tree Size ◽  
Diameter Distribution ◽  
Forest Inventories ◽  
Allometric Relations ◽  
Lidar Measurements ◽  
Derived Data

Remote sensing is an important tool to monitor forests to rapidly detect changes due to global change and other threats. Here, we present a novel methodology to infer the tree size distribution from light detection and ranging (lidar) measurements. Our approach is based on a theoretical leaf–tree matrix derived from allometric relations of trees. Using the leaf–tree matrix, we compute the tree size distribution that fit to the observed leaf area density profile via lidar. To validate our approach, we analyzed the stem diameter distribution of a tropical forest in Panama and compared lidar-derived data with data from forest inventories at different spatial scales (0.04 ha to 50 ha). Our estimates had a high accuracy at scales above 1 ha (1 ha: root mean square error (RMSE) 67.6 trees ha−1/normalized RMSE 18.8%/R² 0.76; 50 ha: 22.8 trees ha−1/6.2%/0.89). Estimates for smaller scales (1-ha to 0.04-ha) were reliably for forests with low height, dense canopy or low tree height heterogeneity. Estimates for the basal area were accurate at the 1-ha scale (RMSE 4.7 tree ha−1, bias 0.8 m² ha−1) but less accurate at smaller scales. Our methodology, further tested at additional sites, provides a useful approach to determine the tree size distribution of forests by integrating information on tree allometries.

scholarly journals Coupled whole‐tree optimality and xylem‐hydraulics explain dynamic biomass partitioning

2021 ◽  
Author(s):  
Aaron Potkay ◽  
Anna T. Trugman ◽  
Yujie Wang ◽  
Martin D. Venturas ◽  
William R.L. Anderegg ◽  
...  
Keyword(s):  
Biomass Partitioning ◽  
Whole Tree

Sand Abrasion Injury and Biomass Partitioning in Cotton Seedlings

2009 ◽  
Vol 101 (6) ◽  
pp. 1297-1303 ◽  
Author(s):  
Jeffrey T. Baker ◽  
Bobbie McMichael ◽  
John J. Burke ◽  
Dennis C. Gitz ◽  
Robert J. Lascano ◽  
...  
Keyword(s):  
Biomass Partitioning ◽  
Sand Abrasion

scholarly journals Biomass Partitioning and Its Relationship with the Environmental Factors at the Alpine Steppe in Northern Tibet

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e81986 ◽  
Author(s):  
Jianbo Wu ◽  
Jiangtao Hong ◽  
Xiaodan Wang ◽  
Jian Sun ◽  
Xuyang Lu ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Biomass Partitioning ◽  
Northern Tibet ◽  
Alpine Steppe

scholarly journals Faecal bacteria in Perna perna (Linnaeus, 1758) (Mollusca: Bivalvia) for biomonitoring coastal waters and seafood quality

2010 ◽  
Vol 58 (spe3) ◽  
pp. 29-35 ◽  
Author(s):  
Diego Igawa Martinez ◽  
Ana Júlia Fernandes Cardoso de Oliveira
Keyword(s):  
Coastal Waters ◽  
Microbiological Quality ◽  
Perna Perna ◽  
Clearance Rates ◽  
Bacterial Concentration ◽  
Allometric Relations ◽  
The Mean ◽  
Negative Impacts ◽  
Faecal Bacteria

Urban development in coastal areas is intense and leads to the increase of sewage outfall and other negative impacts as consequences. Thus, stringent regulations establishing limits to the microbiological contamination of water and seafood are needed. The objective of this study is to evaluate the usefulness of Enterococci and Thermotolerant Coliform densities in the flesh of mussels Perna perna as an alternative tool for monitoring the microbiological quality of coastal waters. The study also considers allometric relations applied to clearance rates to understand rates of bacterial concentration. Bacterial loads obtained in mussels' flesh were from 50 to 4,300 times greater than in the water sampled in the vicinity of the mussels and some were considered inappropriate for consumption even when the water presented no restrictions. The mean clearance rate obtained for Enterococci retention was 317.7 ml h-1 and this rate (CR) is related to the mussels' size (L) by the equation CR = 28.3229L1.6421. The results showed that bacterial densities in the mussels' tissues may reflect chronic contamination of the environment and that clearance rates are important for taking the best decision in situations where, for example, it is desired to introduce mussels for aquaculture and the evaluation of the water concerned is required.

PHYSIOLOGICAL BASIS OF YIELD VARIATION OF TEA (CAMELLIA SINENSIS) DURING DIFFERENT YEARS OF THE PRUNING CYCLE IN THE CENTRAL HIGHLANDS OF SRI LANKA

2009 ◽  
Vol 45 (4) ◽  
pp. 429-450 ◽  
Author(s):  
W. A. J. M. DE COSTA ◽  
D. M. S. NAVARATNE ◽  
A. ANANDACOOMARASWAMY
Keyword(s):  
Harvest Index ◽  
Biomass Partitioning ◽  
Sink Strength ◽  
Down Regulation ◽  
Physiological Basis ◽  
Area Index ◽  
Yield Decline ◽  
Yield Variation ◽  
Shoot Number ◽  
Significant Yield

SUMMARYThe objective of this study was to elucidate the physiological basis of the significant yield decline that occurs during the fourth year of the pruning cycle of tea. Biomass partitioning, which was hypothesized to be a major factor in causing this yield decline, was measured by destructive harvests of entire tea bushes, in two contrasting, mature, field-grown tea cultivars (TRI 2025 and DT1) at the end of different years of the pruning cycle. In both cultivars, yield showed continuous increases from year 1 to 3, followed by reductions of 44% and 35% in TRI2025 and DT1 respectively in the fourth year. Patterns of biomass partitioning to roots, stems or branches did not correlate with the above yield variation whereas harvest index, canopy leaf area index and mature leaf dry weight showed variations which paralleled the yield variation. The fourth-year decline in harvest index was brought about by reductions in both shoot number per m2 and mean individual shoot weight, which indicate a reduction in sink strength. Both cultivars showed reductions in light-saturated photosynthetic rate of maintenance foliage during the second half of the pruning cycle, indicating reduced source capacity. Hence, a combined reduction of both sink strength and source capacity during the fourth year could have brought about the significant yield reduction in tea. A significant increase of root starch in the fourth year indicated a down-regulation of physiological activities of the bush towards the end of the pruning cycle. Mechanisms responsible for this down-regulation need to be elucidated by further research.

Sign in / Sign up

Export Citation Format

Share Document