scholarly journals Biocrust Research in China: Recent Progress and Application in Land Degradation Control

2021 ◽  
Vol 12 ◽  
Author(s):  
Xinrong Li ◽  
Rong Hui ◽  
Huijuan Tan ◽  
Yang Zhao ◽  
Rentao Liu ◽  
...  

Desert ecosystems are generally considered lifeless habitats characterised by extreme environmental conditions, yet they are successfully colonised by various biocrust nonvascular communities. A biocrust is not only an important ecosystem engineer and a bioindicator of desert ecological restoration but also plays a vital role in linking surficial abiotic and biotic factors. Thus, extensive research has been conducted on biocrusts in critical dryland zones. However, few studies have been conducted in the vast temperate deserts of China prior to the beginning of this century. We reviewed the research on biocrusts conducted in China since 2000, which firstly focused on the eco-physiological responses of biocrusts to species composition, abiotic stresses, and anthropological disturbances. Further, research on the spatial distributions of biocrusts as well as their succession at different spatial scales, and relationships with vascular plants and soil biomes (especially underlying mechanisms of seed retention, germination, establishment and survival of vascular plants during biocrust succession, and creation of suitable niches and food webs for soil animals and microorganisms) was analysed. Additionally, studies emphasising on the contribution of biocrusts to ecological and hydrological processes in deserts as well as their applications in the cultivation and inoculation of nonvascular plants for land degradation control and ecological restoration were assessed. Finally, recent research on biocrusts was evaluated to propose future emerging research themes and new frontiers.

2020 ◽  
Vol 748 ◽  
pp. 141552 ◽  
Author(s):  
Chong Jiang ◽  
Haiyan Zhang ◽  
Lingling Zhao ◽  
Zhiyuan Yang ◽  
Xinchi Wang ◽  
...  

Wetlands ◽  
2021 ◽  
Vol 41 (6) ◽  
Author(s):  
Alba Cuena-Lombraña ◽  
Mauro Fois ◽  
Annalena Cogoni ◽  
Gianluigi Bacchetta

AbstractPlants are key elements of wetlands due to their evolutionary strategies for coping with life in a water-saturated environment, providing the basis for supporting nearly all wetland biota and habitat structure for other taxonomic groups. Sardinia, the second largest island of the Mediterranean Basin, hosts a great variety of wetlands, of which 16 are included in eight Ramsar sites. The 119 hydro- and hygrophilous vascular plant taxa from Sardinia represent the 42.6% and 37.9% of the number estimated for Italy and Europe, respectively. Moreover, around 30% of Sardinia’s bryological flora, which is made up of 498 taxa, is present in temporary ponds. An overview at regional scale considering algae is not available, to our knowledge, even though several specific studies have contributed to their knowledge. In order to find the most investigated research themes and wetland types, identify knowledge gaps and suggest recommendations for further research, we present a first attempt to outline the work that has been hitherto done on plants in lentic habitats in Sardinia. Three plant groups (algae, bryophytes and vascular plants), and five research themes (conservation, ecology, inventory, palaeobotany and taxonomy) were considered. After a literature review, we retained 202 papers published from 1960 to 2019. We found that studies on vascular plants, as plant group, were disproportionately more numerous, and inventories and ecology were the most investigated research themes. Although efforts have recently been made to fill these long-lasting gaps, there is a need for updating the existing information through innovative methods and integrative approaches.


2009 ◽  
Vol 33 (2) ◽  
pp. 251-287 ◽  
Author(s):  
Stephen Tooth

Research conducted at the interfaces between traditionally disparate academic disciplines can provide fresh perspectives that catalyse novel research approaches and themes. With particular reference to publications from the last few years, this report focuses on a selection of emerging research themes that highlight the growing links between arid geomorphology and other disciplines, including ecology and soil science, sedimentology and petroleum geology, and planetary science. Three themes are addressed: (1) the role of fire in arid geomorphological systems, characterized by investigations that tend to focus on surface processes and landforms at relatively small spatial scales (plot to short channel reach) and short timescales (hours to years); (2) arid fluvial sedimentary systems, characterized by investigations that commonly focus on processes, landforms and sedimentary products at larger spatial scales (channel reach to basin) and longer timescales (years to millions of years); and (3) arid geomorphology on Mars, commonly characterized by process-landform investigations at very large spatial scales (entire physiographic regions to full planetary contexts) and yet longer timescales (millions to billions of years). For each theme, research gaps are identified, which provides an indication of where the research frontier currently lies. In particular, geomorphological research on Mars and other planetary bodies represents a new physical and intellectual frontier that offers great potential for further interplay with Earth landscape studies in arid and other climatic regions. While there are concerns about the present health and direction of geomorphology and physical geography, this rich diversity of themes provides evidence for vigorous and focused research in arid geomorphology.


2021 ◽  
Vol 170 ◽  
pp. 106359
Author(s):  
J.F. Martín Duque ◽  
I. Zapico ◽  
N. Bugosh ◽  
M. Tejedor ◽  
F. Delgado ◽  
...  

2018 ◽  
Vol 43 (1) ◽  
pp. 24-45 ◽  
Author(s):  
Hannah R Miller ◽  
Stuart N Lane

Matthews’ 1992 geoecological model of vegetation succession within glacial forefields describes how following deglaciation the landscape evolves over time as the result of both biotic and abiotic factors, with the importance of each depending on the level of environmental stress within the system. We focus in this paper on how new understandings of abiotic factors and the potential for biogeomorphic feedbacks between abiotic and biotic factors makes further development of this model important. Disturbance and water dynamics are two abiotic factors that have been shown to create stress gradients that can drive early ecosystem succession. The subsequent establishment of microbial communities and vegetation can then result in biogeomorphic feedbacks via ecosystem engineering that influence the role of disturbance and water dynamics within the system. Microbes can act as ecosystem engineers by supplying nutrients (via remineralization of organic matter and nitrogen fixation), enhancing soil development, either decreasing (encouraging weathering) or increasing (binding sediment grains) geomorphic stability, and helping retain soil moisture. Vegetation can act as an ecosystem engineer by fixing nitrogen, enhancing soil development, modifying microbial community structure, creating seed banks, and increasing geomorphic stability. The feedbacks between vegetation and water dynamics in glacial forefields are still poorly studied. We propose a synthesized model of ecosystem succession within glacial forefields that combines Matthews’ initial geoecological model and Corenblit's model to illustrate how gradients in environmental stress combined with successional time drive the balance between abiotic and biotic factors and ultimately determine the successional stage and potential for biogeomorphic feedbacks.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fanchang Kong ◽  
Meiru Wang ◽  
Xingjie Zhang ◽  
Xiaoyao Li ◽  
Xiaojun Sun

Social networking sites (SNSs) have provided a new platform for people to present their narcissism. The objective of the current study was to investigate the underlying mechanisms between active and passive SNS use and vulnerable narcissism among college students. In achieving this, the study based its method on the media effect and social comparative theory and recruited 529 participants to complete the Surveillance Use Scale, Iowa–Netherlands Comparison Orientation Measure, and Hypersensitivity Narcissistic Scale. The results showed that active and passive SNS use were positively related to upward and downward social comparisons. Active and passive SNS use also indirectly predicted vulnerable narcissism through the parallel mediation of upward and downward social comparisons. This study also revealed the vital role of social comparison in the association between SNS use and vulnerable narcissism.


2015 ◽  
Vol 6 (2) ◽  
pp. 1897-1937 ◽  
Author(s):  
Y. Li ◽  
N. de Noblet-Ducoudré ◽  
E. L. Davin ◽  
N. Zeng ◽  
S. Motesharrei ◽  
...  

Abstract. Previous modeling and empirical studies have shown that the biophysical impact of deforestation is to warm the tropics and cool the extra-tropics. In this study, we use an earth system model to investigate how deforestation at various spatial scales affects ground temperature, with an emphasis on the latitudinal temperature response and its underlying mechanisms. Results show that the latitudinal pattern of temperature response depends non-linearly on the spatial extent of deforestation and the fraction of vegetation change. Compared with regional deforestation, temperature change in global deforestation is greatly amplified in temperate and boreal regions, but is dampened in tropical regions. Incremental forest removal leads to increasingly larger cooling in temperate and boreal regions, while the temperature increase saturates in tropical regions. The latitudinal and spatial patterns of the temperature response are driven by two processes with competing temperature effects: decreases in absorbed shortwave radiation due to increased albedo and decreases in evapotranspiration. These changes in the surface energy balance reflect the importance of the background climate on modifying the deforestation impact. Shortwave radiation and precipitation have an intrinsic geographical distribution that constrains the effects of biophysical changes and therefore leads to temperature changes that are spatially varying. For example, wet (dry) climate favors larger (smaller) evapotranspiration change, thus warming (cooling) is more likely to occur. Further analysis on the contribution of individual biophysical factors (albedo, roughness, and evapotranspiration efficiency) reveals that the latitudinal signature embodied in the temperature change probably result from the background climate conditions rather than the initial biophysical perturbation.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Xiao-Long Li ◽  
Ya-Ming Ji ◽  
Rui Song ◽  
Xiao-Ning Li ◽  
Lan-Shuan Guo

Gastric cancer (GC) is one of the most aggressive malignant tumors with low early diagnosis and high metastasis. Despite progress in treatment, to combat this disease, a better understanding of the underlying mechanisms and novel therapeutic targets is needed. KIF23, which belongs to the KIF family, plays a vital role in various cell processes, such as cytoplasm separation and axon elongation. Nowadays, KIF23 has been found to be highly expressed in multiple tumor tissues and cells, suggesting a potential link between KIF23 and tumorigenesis. Herein, we reported that KIF23 expression was correlated with poor prognosis of gastric cancer and found an association between KIF23 and pTNM stage. An in vitro assay proved that the proliferation of gastric cancer cells was significantly inhibited, which is caused by KIF23 depletion. Additionally, knockdown of KIF23 resulted in a marked inhibition of cell proliferation of gastric cancer in mice, with significant downregulation of Ki67 and PCNA expression. In conclusion, these data indicate that KIF23 is a potential therapeutic target for gastric cancer treatment.


Oecologia ◽  
2020 ◽  
Vol 194 (4) ◽  
pp. 529-539
Author(s):  
Leslie J. Potts ◽  
J. D. Gantz ◽  
Yuta Kawarasaki ◽  
Benjamin N. Philip ◽  
David J. Gonthier ◽  
...  

AbstractSpecies distributions are dependent on interactions with abiotic and biotic factors in the environment. Abiotic factors like temperature, moisture, and soil nutrients, along with biotic interactions within and between species, can all have strong influences on spatial distributions of plants and animals. Terrestrial Antarctic habitats are relatively simple and thus good systems to study ecological factors that drive species distributions and abundance. However, these environments are also sensitive to perturbation, and thus understanding the ecological drivers of species distribution is critical for predicting responses to environmental change. The Antarctic midge, Belgica antarctica, is the only endemic insect on the continent and has a patchy distribution along the Antarctic Peninsula. While its life history and physiology are well studied, factors that underlie variation in population density within its range are unknown. Previous work on Antarctic microfauna indicates that distribution over broad scales is primarily regulated by soil moisture, nitrogen content, and the presence of suitable plant life, but whether these patterns are true over smaller spatial scales has not been investigated. Here we sampled midges across five islands on the Antarctic Peninsula and tested a series of hypotheses to determine the relative influences of abiotic and biotic factors on midge abundance. While historical literature suggests that Antarctic organisms are limited by the abiotic environment, our best-supported hypothesis indicated that abundance is predicted by a combination of abiotic and biotic conditions. Our results are consistent with a growing body of literature that biotic interactions are more important in Antarctic ecosystems than historically appreciated.


2012 ◽  
Vol 33 (4) ◽  
pp. 383-394 ◽  
Author(s):  
Karel Prach ◽  
Jitka Klimešová ◽  
Jiří Košnar ◽  
Olexii Redčenko ◽  
Martin Hais

Abstract Vegetation was described in various spatial scales in the area of 37.8 km2 including distinguishing vegetation units, vegetation mapping, recording phytosociological relevés (53), and completing species lists of vascular plants (86), mosses (124) and lichens (40). Phytosociological relevés were elaborated using ordination methods DCA and CCA. The relevés formed clusters corresponding well to a priori assigned vegetation units. Slope and stoniness significantly influenced the vegetation pattern. Despite the high latitude (nearly 80° N), the vegetation is rather rich in species. Non-native species do not expand. The moss Bryum dichotomum is reported for the first time from Svalbard archipelago.


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