scholarly journals Soil respiration of a Moso bamboo forest significantly affected by gross ecosystem productivity and leaf area index in an extreme drought event

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5747 ◽  
Author(s):  
Yuli Liu ◽  
Guomo Zhou ◽  
Huaqiang Du ◽  
Frank Berninger ◽  
Fangjie Mao ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Moso Bamboo ◽  
Drought Event ◽  
Ecosystem Productivity ◽  
Area Index ◽  
Gross Ecosystem Productivity

Moso bamboo has large potential to alleviate global warming through carbon sequestration. Since soil respiration (Rs) is a major source of CO2 emissions, we analyzed the dynamics of soil respiration (Rs) and its relation to environmental factors in a Moso bamboo (Phllostachys heterocycla cv. pubescens) forest to identify the relative importance of biotic and abiotic drivers of respiration. Annual average Rs was 44.07 t CO2 ha−1 a−1. Rs correlated significantly with soil temperature (P < 0.01), which explained 69.7% of the variation in Rs at a diurnal scale. Soil moisture was correlated significantly with Rs on a daily scale except not during winter, indicating it affected Rs. A model including both soil temperature and soil moisture explained 93.6% of seasonal variations in Rs. The relationship between Rs and soil temperature during a day showed a clear hysteresis. Rs was significantly and positively (P < 0.01) related to gross ecosystem productivity and leaf area index, demonstrating the significance of biotic factors as crucial drivers of Rs.

The effect of ice damage and post-damage fertilization and competition control on understory microclimate of sugar maple (Acer saccharum Marsh.) stands

2003 ◽  
Vol 79 (1) ◽  
pp. 82-90 ◽  
Author(s):  
William C Parker
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Natural Disturbance ◽  
Ice Storm ◽  
Area Index ◽  
Competition Control

The influence of ice damage, fertilization, and herbicide treatments on understory microclimate was examined in several sugar maple stands during three growing seasons. Stands with greater initial crown damage and lower leaf area index had higher understory light levels, elevated air temperatures and lower humidity. Ice damage had comparatively less effect on the below-ground environment. Stands with higher damage and lower leaf area index exhibited higher soil temperature and lower soil moisture availability in certain years. The strength and significance of the relationships of canopy features with microclimatic variables diminished over time with canopy recovery and growth of understory vegetation. Fertilization treatment effects on stand microclimate were not apparent, but competition control reduced understory leaf area, increased soil temperature, and had minimal influence on soil moisture status. Key words: canopy, fertilization, ice storm, microclimate, natural disturbance, sugar maple, vegetation management

scholarly journals Integrating Straw Management and Seeding to Improve Seed Yield and Reduce Environmental Impacts in Soybean Production

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1033
Author(s):  
Cailong Xu ◽  
Ruidong Li ◽  
Wenwen Song ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Management Practice ◽  
Cropping Systems ◽  
Dry Matter Accumulation ◽  
Multiple Cropping ◽  
Area Index

Multiple cropping systems boost grain yields and have an immense potential to increase land productivity. In such cropping systems in China, soybean is directly seeded after the wheat harvest in early June. After the wheat harvest, the farmland has low amounts of soil moisture and contains large amounts of wheat straw, which negatively affect soybean growth and yields. To address these challenges, an integrated management practice (IMP) than can achieve precise direct seeding and straw mulching return, was developed. In this study, differences in the soil temperature and moisture, seedling quality, dry matter accumulation, soybean yield, and greenhouse gas emissions were investigated between IMP and the farmers’ practices (FP). Compared with the FP treatment, IMP significantly increased the soil moisture and decreased the soil temperature in the topsoil layer. In addition, under the IMP treatment, the rate of emergence and developmental uniformity of soybean plants significantly increased by 21.7% and 99.5%, respectively, thus increasing the leaf area index by 30.0% and dry matter accumulation by 12.0% and, in turn, increasing soybean yields by 24.7%. A principal component analysis showed that the dry matter weight, relative water content, leaf area index, and developmental uniformity were strong sensitivity indices for the IMP treatment. In addition, the intensity of emission of N2O and greenhouse gases under IMP both decreased significantly by 25.1% and 28.9% compared with the FP, respectively. Thus, it was concluded that IMP is a suitable farming practice for sustainable agricultural production, and it has broad prospects for application in wheat–soybean double cropping systems in China and other similar areas globally.

scholarly journals MODIS vegetation products as proxies of photosynthetic potential along a gradient of meteorologically and biologically driven ecosystem productivity

2016 ◽  
Vol 13 (19) ◽  
pp. 5587-5608 ◽  
Author(s):  
Natalia Restrepo-Coupe ◽  
Alfredo Huete ◽  
Kevin Davies ◽  
James Cleverly ◽  
Jason Beringer ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Photosynthetic Active Radiation ◽  
Ecosystem Structure ◽  
Ecosystem Productivity ◽  
Area Index ◽  
Active Radiation ◽  
Flux Tower ◽  
Photosynthetic Potential ◽  
Assimilation Capacity

Abstract. A direct relationship between gross ecosystem productivity (GEP) estimated by the eddy covariance (EC) method and Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices (VIs) has been observed in many temperate and tropical ecosystems. However, in Australian evergreen forests, and particularly sclerophyll and temperate woodlands, MODIS VIs do not capture seasonality of GEP. In this study, we re-evaluate the connection between satellite and flux tower data at four contrasting Australian ecosystems, through comparisons of GEP and four measures of photosynthetic potential, derived via parameterization of the light response curve: ecosystem light use efficiency (LUE), photosynthetic capacity (Pc), GEP at saturation (GEPsat), and quantum yield (α), with MODIS vegetation satellite products, including VIs, gross primary productivity (GPPMOD), leaf area index (LAIMOD), and fraction of photosynthetic active radiation (fPARMOD). We found that satellite-derived biophysical products constitute a measurement of ecosystem structure (e.g. leaf area index – quantity of leaves) and function (e.g. leaf level photosynthetic assimilation capacity – quality of leaves), rather than GEP. Our results show that in primarily meteorological-driven (e.g. photosynthetic active radiation, air temperature, and/or precipitation) and relatively aseasonal ecosystems (e.g. evergreen wet sclerophyll forests), there were no statistically significant relationships between GEP and satellite-derived measures of greenness. In contrast, for phenology-driven ecosystems (e.g. tropical savannas), changes in the vegetation status drove GEP, and tower-based measurements of photosynthetic activity were best represented by VIs. We observed the highest correlations between MODIS products and GEP in locations where key meteorological variables and vegetation phenology were synchronous (e.g. semi-arid Acacia woodlands) and low correlation at locations where they were asynchronous (e.g. Mediterranean ecosystems). However, we found a statistical significant relationship between the seasonal measures of photosynthetic potential (Pc and LUE) and VIs, where each ecosystem aligns along a continuum; we emphasize here that knowledge of the conditions in which flux tower measurements and VIs or other remote sensing products converge greatly advances our understanding of the mechanisms driving the carbon cycle (phenology and climate drivers) and provides an ecological basis for interpretation of satellite-derived measures of greenness.

Estimation of Leaf Area Index of Moso Bamboo Canopies

2021 ◽  
pp. 1-16
Author(s):  
Feilong Huang ◽  
Weiliang Fan ◽  
Huaqiang Du ◽  
Xiaojun Xu ◽  
Jun Wu ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Moso Bamboo ◽  
Area Index
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