Changes in Cupressus funebris and Cryptomeria fortunei Root Parameters in Landslides Caused by the Wenchuan Earthquake

2011 ◽  
Vol 378-379 ◽  
pp. 381-384 ◽  
Author(s):  
Hui Yu ◽  
Song Cheng ◽  
Gang Yang ◽  
Yong Heng Gao ◽  
Zhong You Zhang ◽  
...  

Strong earthquakes (>7.0 Ms) critically change pedosphere, how the changed soils disturb tree root growth related to forest restoration is unclear globally. Therefore, a total of 15 plots were established in non-removed and landslide areas of Cupressus funebris and Cryptomeria fortunei plantations near northern section of fault belt of Wenchuan Earthquake (8.0 Ms) occurring in May 12, 2008, China. 112 and 114 small fine roots (≤2.0 mm in diameter) in all the plots were sampled in June and October of 2009. Mean tips length/length, area/ length, volume/length, mean tips length/biomass, specific root area and specific root length in 0.0–0.5, >0.5–1.0 and >1.0–2.0 mm diameters of roots were examined. This study revealed 1) root parameters did not respond to the landslide soils in the June, but did until the October, suggesting after many root tips and tiny roots die in winter, the roots lose sensitivity to a changing soil environment; 2) mean tips length/length and mean tips length/biomass decreased for Cupressus funebris, and increased for Cryptomeria fortunei as well as area/length and volume/length in the landslide soils, implying both species roots have different processes of forest restoration; 3) the smallest sized roots were more sensitive to the landslide soils than the other sized roots, which are better indicators for the forest restoration.

2009 ◽  
Vol 39 (10) ◽  
pp. 1787-1796 ◽  
Author(s):  
Ivika Ostonen ◽  
Leho Tedersoo ◽  
Triin Suvi ◽  
Krista Lõhmus

Ectomycorrhizal (EcM) fungi contribute significantly to the shaping of short-root morphology, playing an important role in balancing the costs and benefits of root growth and nutrient uptake and exchange in boreal forests. We aimed to assess the effect of various EcM fungal taxa on root traits at seven sites dominated by grey alder, Alnus incana (L.) Moench, and black alder, Alnus glutinosa (L.) Gaertn. Mean root size, specific root length, specific root area, root tissue density, and root-tip frequency of EcM short roots were measured in EcM anatomotypes in relation to the effects of host species, soil moisture level, and nutrient status. Redundancy analysis revealed that anatomotype, alder species, site, and soil parameters (N, P, K, Ca, and Mg concentrations, pH, organic-matter content) accounted for 42.3% (p < 0.001) of the total variation in EcM root morphology. Variation decreased in the following order: anatomotypes (27.9%) > soil parameters and sites (19.9%) > alder species (5.1%). EcM fungus species had the primary influence on EcM short-root size. EcM roots of the dominant anatomotype, Alnicola spp., had the highest specific root length and specific root area in both alder species. Short-root morphology depends most strongly on the fungal taxa involved, which indicates that the type of mycobiont has an important influence on the functional properties of fine roots.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tina Unuk Nahberger ◽  
Gian Maria Niccolò Benucci ◽  
Hojka Kraigher ◽  
Tine Grebenc

AbstractSpecies of the genus Tuber have gained a lot of attention in recent decades due to their aromatic hypogenous fruitbodies, which can bring high prices on the market. The tendency in truffle production is to infect oak, hazel, beech, etc. in greenhouse conditions. We aimed to show whether silver fir (Abies alba Mill.) can be an appropriate host partner for commercial mycorrhization with truffles, and how earthworms in the inoculation substrate would affect the mycorrhization dynamics. Silver fir seedlings inoculated with Tuber. aestivum were analyzed for root system parameters and mycorrhization, how earthworms affect the bare root system, and if mycorrhization parameters change when earthworms are added to the inoculation substrate. Seedlings were analyzed 6 and 12 months after spore inoculation. Mycorrhization with or without earthworms revealed contrasting effects on fine root biomass and morphology of silver fir seedlings. Only a few of the assessed fine root parameters showed statistically significant response, namely higher fine root biomass and fine root tip density in inoculated seedlings without earthworms 6 months after inoculation, lower fine root tip density when earthworms were added, the specific root tip density increased in inoculated seedlings without earthworms 12 months after inoculation, and general negative effect of earthworm on branching density. Silver fir was confirmed as a suitable host partner for commercial mycorrhization with truffles, with 6% and 35% mycorrhization 6 months after inoculation and between 36% and 55% mycorrhization 12 months after inoculation. The effect of earthworms on mycorrhization of silver fir with Tuber aestivum was positive only after 6 months of mycorrhization, while this effect disappeared and turned insignificantly negative after 12 months due to the secondary effect of grazing on ectomycorrhizal root tips.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tianbao Ren ◽  
Huanhuan Wang ◽  
Ye Yuan ◽  
Huilin Feng ◽  
Bo Wang ◽  
...  

AbstractIn order to explore the effects of biochar on root system and growth characteristics of flue-tobacco, three years of field experiments were conducted to study the influence of different biochar application levels [600 (T1), 1200 (T2), 1800(T3), 2400 (T4), 3000 (T5) kg/ha] and no fertilizer (CK) on the root physiological indexes and growth index of tobacco. Compared with local conventional fertilization, the application rate of N fertilizer in each treatment (except for control) was reduced by 40% to analyze the effects of different amount of biochar on the physiological indexes of tobacco roots and leaf photosynthesis during flourishing. The results showed that tobacco plants' root development status in the flourishing period was consistent with the photosynthetic physiological indexes, chlorophyll content, and leaf-area coefficient. Compared with the control, the application of biochar could increase the root vigor by 177.8%. Biochar improved the roots, increasing the total root area by 91.35% and the number of root tips by 100.9%. Meanwhile, biochar increased the net photosynthetic rate of tobacco leaves by 77.3% and the total tobacco biomass by 72.5%. Studies have shown that biochar can promote the development of tobacco roots, and then enhance the photosynthesis of leaves, so that tobacco plants can grow healthily, which is conducive to the tobacco production and the cultivation of soil.


2011 ◽  
Vol 255-260 ◽  
pp. 3642-3645
Author(s):  
Kai Hua Zeng ◽  
Hai Yan Ju ◽  
Han Xing Peng

Earthquake occurred on May 12, 2008 in Wenchuan, Sichuan Province, China, with magnitude of 8.0 and epicenter intensity of VI. Chencun hydropower station in southern Anhui Province has been shocked strongly during Wenchuan Earthquake, which stations 1,500 km away from Wenchuan. Tectonic stress caused by strong earthquakes inevitably led to the changes of stress state, groundwater level and pore pressure in the dam foundation. Seepage water level observation of the dam foundation had been encrypted immediately. According to the experimental data, it was conformed that significant effects were displayed on the dam foundation seepage because of Wenchuan earthquake, shunhe fault near dam sites was the main effect zone of earthquake tectonic stress, the downrange of groundwater depth was self-evident. As the existence of acrylamide curtain, swelling-shrinkage property of the acrylamide gel restricted the change of groundwater level and rock stress state in the dam foundation caused by seismic tectonic stress; the groundwater level behind the acrylamide curtain had a small decline, and recovering quickly.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jian-Wei Zong ◽  
Zhi-Long Zhang ◽  
Pei-Lu Huang ◽  
Nai-Yu Chen ◽  
Ke-Xin Xue ◽  
...  

Xanthoceras sorbifolium Bunge is priced for its medical and energetic values. The species also plays a key role in stabilizing ecologically fragile areas exposed to excess soil salinity. In this study, the effects of salinity on the growth, physiological, and photosynthetic parameters of X. sorbifolium Bunge were investigated. The X. sorbifolium seedlings were subjected to five salt treatments: 0 (control, CK), 70, 140, 210, and 280 mM of sodium chloride (NaCl) solutions. NaCl caused a decrease in plant height, specific leaf area, biomass, and root parameters. Leaf wilting and shedding and changes in root morphology, such as root length, root surface area, and root tips were observed. This study found that X. sorbifolium is tolerant to high salinity. Compared with the CK group, even if the concentration of NaCl was higher than 210 mM, the increase of the relative conductivity was also slow, while intercellular CO2 concentration had a similar trend. Moreover, NaCl stress caused an increase in the malondialdehyde (MDA), soluble proteins, and proline. Among the enzymes in the plant, the catalase (CAT) activity increases first and decreased with the increase in the intensity of NaCl stress, but the salt treatment had no significant effect on superoxide dismutase (SOD) activity. The peroxidase (POD) showed an increasing trend under salt stress. It was found that the photosynthesis of X. sorbifolium was notably impacted by saline stress. NaCl toxicity induced a noticeable influence on leaf net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (E), and water use efficiency (Wue). As salt concentration increased, the content of chlorophyll decreased. It can be found that a low concentration of NaCl induced the increase of photosynthetic capacity but a high-intensity exposure to stress resulted in the reduction of photosynthetic efficiency and SOD activity, which had a positive correlation. In summary, salt-induced ionic stress primarily controlled root morphology, osmotic adjustment, and enzyme activities of salt-treated X. sorbifolium leaves, whereas the low salt load could, in fact, promote the growth of roots.


2012 ◽  
Vol 12 (2) ◽  
pp. 351-363 ◽  
Author(s):  
X. L. Chen ◽  
Q. Zhou ◽  
H. Ran ◽  
R. Dong

Abstract. Southwest China is located in the southeastern margin of the Tibetan Plateau and it is a region of high seismic activity. Historically, strong earthquakes that occurred here usually generated lots of landslides and brought destructive damages. This paper introduces several earthquake-triggered landslide events in this region and describes their characteristics. Also, the historical data of earthquakes with a magnitude of 7.0 or greater, having occurred in this region, is collected and the relationship between the affected area of landslides and earthquake magnitude is analysed. Based on the study, it can be concluded that strong earthquakes, steep topography as well as fragile geological environment, are the main reasons responsible for serious landslides in southwest China. At the same time, it is found that the relationship between the area affected by landslides and the earthquake magnitude in this region are consistent with what has been obtained worldwide. Moreover, in this paper, it is seen that the size of the areas affected by landslides change enormously even under the same earthquake magnitude in the study region. While at the same tectonic place or fault belt, areas affected by landslides presented similar outline and size. This means that local geological conditions and historical earthquake background have an important influence on landslides distribution, and they should be considered when assessing earthquake-triggered landslide hazards at Grade 1 according to ISSMGE.


1989 ◽  
Vol 119 (2) ◽  
pp. 245-249 ◽  
Author(s):  
K. Lõhmus ◽  
T. Oja ◽  
R. Lasn

2021 ◽  
Author(s):  
M.D. Dhin Islam ◽  
Adam H. Price ◽  
Paul D. Hallett

Abstract Aims Cracks and biopores in compacted soil such as plough pans could aid deep rooting, mitigating constraints to seasonal upland use of paddy fields for rice production. This research investigated how soil macropores through a simulated plough pan affects root growth of contrasting deep and shallow rooting rice genotypes. Methods Deep rooting Black Gora and shallow rooting IR64 rice varieties were grown in packed cores of unsaturated soil in a controlled greenhouse. Simulated biopores and cracks (macropores) were inserted through the plough pan to form treatments with no macropores, biopores, cracks, and combined cracks and biopores. Different root parameters such as root length density (RLD), root volume, root diameter, number of root tips and branches were measured. The number of roots was calculated manually, including the number of roots growing through macropores in the plough pan layer. Results Plough pans with macropores had 25–32% more roots than with no macropores. RLD was 55% greater in the plough pan layer if cracks were present compared to biopores. Conversely, RLD was 26% less in subsoil if the plough pan had cracks compared to biopores. Different root parameters were greatly influenced by the presence of macropores in the plough pan, and deep-rooted Black Gora produced 81% greater RLD, 30% more root numbers and 103% more branching than the shallow rooted rice genotype IR64 within the plough pan layer. Conclusions Macropores greatly improve rice root growth through plough pans for a deep rooting but not a shallow rooting rice variety. Whereas cracks produce a greater number of roots in the plough pan, biopores result in greater root branching and root numbers deeper in subsoil.


2021 ◽  
Author(s):  
Jingru Zhang ◽  
Zhengkun Hu ◽  
Chongzhe Zhang ◽  
Yiheng Tao ◽  
Xiaoyun Chen ◽  
...  

Abstract Aims Roots bridge above and belowground systems, and play a pivotal role in structuring root-associated organisms via influencing food resources and habitat conditions. Most studies focused on the relationships between plant identity and root-associated organisms, however, little is known about how root traits affect nematode communities within the rhizosphere. Methods We investigated the relationships between root traits of four plant species and nematode diversity, community structure and trophic complexity in an ex-arable field. Results While the relative abundance of herbivorous nematodes was negatively associated with specific root length (SRL), specific root area (SRA), root length density (RLD) and root C: N ratio, free-living nematodes were positively affected by these traits, implying a multifaceted effect of root traits on root-associated organisms. Importantly, we found that finer root systems promoted the complexity of the nematode community, by increasing the relative abundance of high trophic-level nematodes (i.e., omnivores and predators) and enhancing nematode diversity. Conclusion Our findings suggest that root traits could be reliable indicators of soil community structure and interactions, and provide new insights into soil biodiversity and functional maintenance.


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