Diversity of Soil Animal Community in Microhabitats of Alpine Coniferous Forest at Early Stage of Growing Season

2012 ◽  
Vol 18 (2) ◽  
pp. 303
Author(s):  
Lei XIA ◽  
Jian ZHANG ◽  
Wanqin YANG ◽  
Fuzhong WU
Keyword(s):  
Early Stage ◽  
Coniferous Forest ◽  
Growing Season ◽  
Soil Animal ◽  
Animal Community

scholarly journals Spatio-Temporal Variation of Drought within the Vegetation Growing Season in North Hemisphere (1982–2015)

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2146 ◽  
Author(s):  
Zhaoqi Zeng ◽  
Yamei Li ◽  
Wenxiang Wu ◽  
Yang Zhou ◽  
Xiaoyue Wang ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Gross Primary Production ◽  
Coniferous Forest ◽  
Critical Time ◽  
Growing Season ◽  
Well Being ◽  
Estimation Methods ◽  
Drought Risk ◽  
Drought Characteristics ◽  
The Impact

Drought disasters jeopardize the production of vegetation and are expected to exert impacts on human well-being in the context of global climate change. However, spatiotemporal variations in drought characteristics (including the drought duration, intensity, and frequency), specifically for vegetation areas within a growing season, remain largely unknown. Here, we first constructed a normalized difference vegetation index to estimate the length of the growing season for each pixel (8 km) by four widely used phenology estimation methods; second, we analyzed the temporal and spatial patterns of climate factors and drought characteristics (in terms of the Standardized Precipitation Evapotranspiration Index (SPEI)), within a growing season over vegetation areas of the northern hemisphere before and after the critical time point of 1998, which was marked by the onset of a global warming hiatus. Finally, we extracted the highly drought-vulnerable areas of vegetation by examining the sensitivity of the gross primary production to the SPEI to explore the underlying effects of drought variation on vegetation. The results revealed, first, that significant (p < 0.05) increases in precipitation, temperature, and the SPEI (a wetting trend) occurred from 1982 to 2015. The growing season temperature increased even more statistically significant after 1998 than before. Second, the duration and frequency of droughts changed abruptly and decreased considerably from 1998 to 2015; and this wetting trend was located mainly in high-latitude areas. Third, at the biome level, the wetting areas occurred mainly in the tundra, boreal forest or taiga, and temperate coniferous forest biomes, whereas the highly drought-vulnerable areas were mainly located in the desert and xeric shrubland (43.5%) biomes. Our results highlight the fact that although the drought events within a growing season decreased significantly in the northern hemisphere from 1998 to 2015, the very existence of a mismatch between a reduction in drought areas and an increase in highly drought-vulnerable areas makes the impact of drought on vegetation nonnegligible. This work provides valuable information for designing coping measures to reduce the vegetative drought risk in the Northern Hemisphere.

Remote sensing of geological structure in temperate agricultural terrains

1986 ◽  
Vol 123 (2) ◽  
pp. 113-121 ◽  
Author(s):  
S. A. Drury
Keyword(s):  
Near Infrared ◽  
Early Stage ◽  
Plant Cells ◽  
Growing Season ◽  
Geological Structure ◽  
Thematic Mapper ◽  
Landsat Thematic Mapper ◽  
Common Elements ◽  
Bond Stretching ◽  
Absorption Features

AbstractAgricultural patterns dominate most remotely sensed images of lowland north Europe and camouflage shadow patterns related to topography and hence to underlying geological structure. Images of those parts of the near-infrared spectrum close to absorption features controlled by H–O–H bond stretching in plant cells and soil moisture largely remove this hindrance to interpretation, if they are acquired at an early stage in the growing season. The most easily available and most useful images of this type are those of band 5 from the Landsat Thematic Mapper. Spatial filtering techniques applied to digital images can enhance them for structural interpretation if filter matrices and viewing scales are chosen to match the dimensions of the most common elements of the landscape and the peak of visual acuity. Filters to enhance directional attributes of an agricultural scene give appealing results but contain spurious linear features that masquerade as faults.

scholarly journals Effects of straw incorporation on nitrogen absorption of split fertilizer applications and on rice growth

2019 ◽  
pp. 59
Author(s):  
Jicheng Zheng, Gang Zhang, D. Wang, Z. Cao, C. Wang ◽  
Dezhi Yan
Keyword(s):  
Root Growth ◽  
Late Stage ◽  
Dry Matter ◽  
Early Stage ◽  
Growing Season ◽  
Total N ◽  
Residual Rate ◽  
Negative Effect ◽  
Straw Incorporation ◽  
Rice Growing Season

A greenhouse experiment investigated the effect and mechanism of straw incorporation (0 and 6 t ha−1) on the absorption of fertilizer nitrogen (N) of split applications and on the growth of rice shoots and roots. N fertilizer was split into: (1) base fertilizer (BF), incorporated before transplanting; (2) tillering fertilizer (TF), broadcasted at tillering stage; and (3) panicle-formation fertilizer (PF), broadcasted at panicle-formation stage. 15N-urea was used as one of three splits. To evaluate the hypothesis that straw incorporation influences the 15N absorption of one split by enhancing 15N immobilization or changing root growth, we measured the 15N residual rate in soil at maturity and root growth throughout the rice-growing season. Straw incorporation significantly decreased 15N absorption of BF, accompanied by significantly higher 15N immobilization in soil than in the no-straw treatment. However, straw incorporation significantly increased 15N absorption of top-dressing (both TF and PF), accompanied by significantly greater dry matter and length of surface roots (0–5 cm depth) throughout the rice-growing season (top-dressing 15N was seldom found in soils > 5 cm). Shoot dry matter with straw incorporation decreased significantly in the early stage but increased in the late stage, compared with the no-straw treatment, and shoot total N with straw incorporation decreased significantly throughout the rice-growing season (this negative effect had decreased by the late stage). To better synchronize N supply with rice demand and reduce the risk of water eutrophication, N levels of BF and top-dressing should be reviewed when straw is incorporated.

scholarly journals Growing season precipitation in Finland under recent and projected climate

2010 ◽  
Vol 10 (7) ◽  
pp. 1563-1574 ◽  
Author(s):  
J. S. Ylhäisi ◽  
H. Tietäväinen, ◽  
P. Peltonen-Sainio ◽  
A. Venäläinen ◽  
J. Eklund ◽  
...  
Keyword(s):  
Crop Production ◽  
Early Stage ◽  
Regional Climate ◽  
Growing Season ◽  
Agricultural Crop ◽  
Sampling Errors ◽  
The South ◽  
North East ◽  
The North ◽  
North Eastern

Abstract. The past and projected future precipitation sum in May–September for two areas in Finland, one located in the south-west (SW) and the other in the north-east (NE), is studied using 13 regional climate simulations and three observational datasets. The conditions in the present-day climate for agricultural crop production are far more favourable in the south-western part of the country than the more continental north-eastern Finland. Based on a new high-resolution observational precipitation dataset for Finland (FMI_grid), with a resolution of 10×10 km, the only statistically significant past long-term (1908–2008) precipitation tendencies in the two study regions are positive. Differences between FMI_grid and two other observational datasets during 1961–2000 are rather large in the NE, whereas in the SW the datasets agree better. Observational uncertainties stem from the interpolation and sampling errors. The projected increases in precipitation in the early stage of the growing season would be most favourable for agricultural productivity, but the projected increases in August and September might be harmful. Model projections for the future indicate a statistically significant increase in precipitation for most of the growing season by 2100, but the distribution of precipitation within the growing season is not necessarily the most optimal.

scholarly journals The role of arbuscular mycorrhizal fungi on the early-stage restoration of seasonally dry tropical forest in Chamela, Mexico

2012 ◽  
Vol 36 (2) ◽  
pp. 279-289 ◽  
Author(s):  
Pilar Huante ◽  
Eliane Ceccon ◽  
Alma Orozco-Segovia ◽  
María Esther Sánchez-Coronado ◽  
Irma Acosta ◽  
...  
Keyword(s):  
Plant Height ◽  
Ecological Restoration ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Early Stage ◽  
Growing Season ◽  
Dry Forest ◽  
Individual Plant ◽  
Functional Characteristics ◽  
Leaf Production

It was evaluated the effect of two different sources of local inocula from two contrasting sites (mature forest, pasture) of arbuscular mycorrhizae fungi (AMF) and a non-mycorrhizal control on the plant growth of six woody species differing in functional characteristics (slow-, intermediate- and fast-growth), when introduced in a seasonally tropical dry forest (STDF) converted into abandoned pasture. Six plots (12 X 12m) were set as AMF inoculum source. Six replicates of six different species arranged in a Latin Square design were set in each plot. Plant height, cover area and the number of leaves produced by individual plant was measured monthly during the first growing season in each treatment. Species differed in their ability to benefit from AMF and the largest responsiveness in plant height and leaf production was exhibited by the slow-growing species Swietenia humilis, Hintonia latiflora and Cordia alliodora. At the end of the growing season (November), the plant height of the fast growing species Tabebuia donnel-smithii, Ceiba pentandra and Guazuma ulmifolia were not influenced by AMF. However, inocula of AMF increased leaf production of all plant species regardless the functional characteristics of the species, suggesting a better exploitation of above-ground space and generating a light limited environment under the canopy, which contributed to pasture suppression. Inoculation of seedlings planted in abandoned pasture areas is recommended for ecological restoration due to the high responsiveness of seedling growth in most of species. Use of forest inoculum with its higher diversity of AMF could accelerate the ecological restoration of the above and below-ground comunities.

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