scholarly journals Niche Differentiation and Co-Occurrence Network of Fungal Communities Associated with Host Affiliations in an Extremely Arid Desert Ecosystem

2020 ◽  
Author(s):  
Yiling Zuo ◽  
Xia Li ◽  
Jingya Yang ◽  
Jiaqiang Liu ◽  
Xueli He ◽  
...  
Keyword(s):  
Endophytic Fungi ◽  
Sequence Similarity ◽  
Mutual Exclusion ◽  
Keystone Species ◽  
Fungal Communities ◽  
Desert Ecosystem ◽  
Desert Plants ◽  
Desert Ecosystems ◽  
Desert Shrubs ◽  
Arid Desert

Abstract Background: Desert shrubs represent high productivity and play essential roles in maintaining the biodiversity and stability of ecosystem functioning in arid desert ecosystems. These xerophytic plants provide specific biotic and abiotic conditions for the resident specialist microorganisms. However, a robust understanding of the structural composition of the fungal microbiome associated with desert plants and especially the relationship between above- and belowground communities is currently lacking. In this study, we examined the endophytic fungal communities associated with the root, stem, and leaf tissues of five desert shrubs using Illumina MiSeq sequencing of internal transcribed spacer 2 (ITS2) sequences.Results: A total of 337 operational taxonomic units (OTUs) of endophytic fungi were identified at a 97% sequence similarity level. Pleosporales were dominant and played an irreplaceable role as keystone species in maintaining the connectivity and complexity of the fungal networks. Desert shrub identity significantly affected the community composition of the endophytic fungi in different tissues. Compared with the fungi in the aboveground tissues, root-associated fungi represented the most abundant reservoir of biodiversity in the desert habitat and displayed significantly high tissue specificity. Interestingly, the aboveground stems and leaves showed higher taxonomic overlap with underground root tissues than with each other. The root fungal network revealed the highest connectivity, and the interspecies relationships between desert fungal OTUs revealed a high percentage of co-presence rather than mutual exclusion. In addition, members of Hypocreales played a central role in connecting the above- and belowground fungal networks.Conclusions: This study represents the first example of research revealing plant-fungus endophytic associations in an extremely arid desert ecosystem with the simultaneous consideration and comparison of above- and belowground niches. Understanding the complex host-microbe interactions associated with desert plants could provide a basis for the exploitation of plant-fungus associations in the manipulation of the shrub microbiome for ecological restoration purposes.

scholarly journals Seed Predation on Oil-Polluted and Unpolluted Vachellia (Acacia) Trees in a Hyper-Arid Desert Ecosystem

Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 665
Author(s):  
Marco Ferrante ◽  
Daniella M. Möller ◽  
Gabriella M. Möller ◽  
Yael Lubin ◽  
Michal Segoli
Keyword(s):  
Oil Spill ◽  
Seed Predation ◽  
Oil Pollution ◽  
Keystone Species ◽  
Ground Level ◽  
Desert Ecosystem ◽  
Arid Environments ◽  
Animal Diversity ◽  
Arid Desert ◽  
Predation Rates

Acacia trees are keystone species in many arid environments, supporting high levels of plant and animal diversity. In Israel, the populations of Vachellia (formerly Acacia) tortilis (Forssk.) and V. raddiana (Savi) are declining at an alarming rate. Severe infestations by bruchid beetles (Coleoptera, Chrysomelidae) are among the major causes of seed mortality, but additional environmental stressors can reduce the defence level of the seeds, exacerbating their susceptibility to predators. In a hyper-arid desert ecosystem affected by two major oil spills (in 1975 and 2014), we quantified seed predation rates caused by insect granivores before and after the pods dropped to the ground. We recorded predation rates of up to 84% for both tree species, and higher predation rates at the ground level than in the canopy, suggesting that repeated infestations occur. These results reinforce the call to protect the populations of large ungulates such as gazelles, which kill the bruchids by feeding upon the pods, and promote seed germination and dispersion. We found no clear evidence of a negative effect of the oil spill on seed predation, indicating that oil pollution did not increase the vulnerability of the seeds to granivores even in trees affected by the recent oil spill.

scholarly journals Diversity and community of culturable endophytic fungi from stems and roots of desert halophytes in northwest China

MycoKeys ◽  
2020 ◽  
Vol 62 ◽  
pp. 75-95 ◽  
Author(s):  
Jia-Long Li ◽  
Xiang Sun ◽  
Yong Zheng ◽  
Peng-Peng Lü ◽  
Yong-Long Wang ◽  
...  
Keyword(s):  
Species Richness ◽  
Endophytic Fungi ◽  
Fungal Community ◽  
Northwest China ◽  
Desert Ecosystem ◽  
Tissue Type ◽  
Fungal Community Composition ◽  
Desert Ecosystems ◽  
High Species Diversity ◽  
Host Identity

Halophytes have high species diversity and play important roles in ecosystems. However, endophytic fungi of halophytes in desert ecosystems have been less investigated. In this study, we examined endophytic fungi associated with the stem and root of ten halophytic species colonizing the Gurbantonggut desert. A total of 36 endophytic fungal taxa were obtained, dominated by Alternaria eichhorniae, Monosporascus ibericus, and Pezizomycotina sp.1. The colonization rate and species richness of endophytic fungi varied in the ten plant species, with higher rates in roots than in stems. The endophytic fungal community composition was significantly affected by plant identity and tissue type. Some endophytic fungi showed significant host and tissue preferences. This finding suggests that host identity and tissue type structure endophytic fungal community in a desert ecosystem.

scholarly journals Differential intra-specific stemflow funnelling efficiencies of Caragana korshinskii within arid desert ecosystems

2017 ◽  
Vol 48 (6) ◽  
pp. 1611-1623 ◽  
Author(s):  
Ya-feng Zhang ◽  
Xin-ping Wang ◽  
Rui Hu ◽  
Yan-xia Pan
Keyword(s):  
Northern China ◽  
Desert Ecosystem ◽  
Absolute Amount ◽  
Desert Ecosystems ◽  
Rainfall Events ◽  
Rainfall Condition ◽  
Caragana Korshinskii ◽  
Specific Variation ◽  
Morphological Differences ◽  
Arid Desert

Abstract Stemflow is known as a highly localized point input of rainwater and solutes around tree/shrub bases where roots are concentrated, thus having considerable effects on hydrology and biogeochemistry of vegetated ecosystems. Stemflow shows a pronounced inter-specific variation due to morphological differences among species, while the intra-specific variation of stemflow has been poorly explored. We systematically examined the effects of shrub morphological metrics on intra-specific funnelling efficiencies by quantifying the stemflow of nine shrubs of Caragana korshinskii within a water-limited arid desert ecosystem of northern China. Stemflow volume was used to compare the absolute amount of stemflow generated by shrubs of varying size, and funnelling ratio was used to assess their funnelling efficiencies. Both rainfall depth and shrub morphological metrics significantly affected stemflow volume, while funnelling ratio was more associated with shrub morphology. Under the same rainfall condition, smaller shrubs produced lower volumes of stemflow, while gaining access to rainfall via higher funnelling ratio than larger shrubs. Our findings highlight a large variation in funnelling efficiency among individual shrubs within the same species, and in particular, smaller shrubs might profit more from sporadic small rainfall events than larger shrubs.

scholarly journals Oil Pollution Affects the Central Metabolism of Keystone Vachellia (Acacia) Trees

2021 ◽  
Vol 13 (12) ◽  
pp. 6660
Author(s):  
Marco Ferrante ◽  
Anuma Dangol ◽  
Shoshana Didi-Cohen ◽  
Gidon Winters ◽  
Vered Tzin ◽  
...  
Keyword(s):  
Oil Spills ◽  
Oil Pollution ◽  
Keystone Species ◽  
Desert Ecosystem ◽  
Arid Environments ◽  
Central Metabolism ◽  
Adult Trees ◽  
Metabolite Profiles ◽  
One Year

Vachellia (formerly Acacia) trees are native to arid environments in Africa and the Arabian Peninsula, where they often support the local animal and plant communities acting as keystone species. The aim of this study was to examine whether oil pollution affected the central metabolism of the native keystone trees Vachellia tortilis (Forssk.) and V. raddiana (Savi), as either adults or seedlings. The study was conducted in the Evrona Nature Reserve, a desert ecosystem in southern Israel where two major oil spills occurred in 1975 and in 2014. Leaf samples were collected to analyze the central metabolite profiles from oil-polluted and unpolluted adult trees and from Vachellia seedlings growing in oil-polluted and unpolluted soils in an outdoor setup. We found that oil pollution had a stronger effect on one-year-old seedlings than on adult trees, reducing the levels of amino acids, sugars, and organic acids. While adult trees are mildly affected by oil pollution, the effects on young seedlings can cause a long-term reduction in the population of these keystone desert trees, ultimately threatening this entire ecosystem.

scholarly journals Rainfall in growing season determines the size of an annual-dominated soil seed bank in a desert ecosystem

2020 ◽  
Author(s):  
Ya-Fei Shi ◽  
Zengru Wang ◽  
Bing-Xin Xu ◽  
Jian-Qiang Huo ◽  
Rui Hu ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Species Composition ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Growing Season ◽  
Seed Banks ◽  
Desert Ecosystem ◽  
Perennial Herb ◽  
Desert Ecosystems ◽  
Soil Seed Banks

Soil seed banks may offer great potential for restoring and maintaining desert ecosystems that have been degraded by climate change and anthropogenic disturbance. However, few studies have explored the annual dynamics in the composition and relative abundance of these soil seed banks. We conducted a long-term observational study to assess the effects of environmental factors (meteorology and microtopography) and aboveground vegetation on the soil seed bank of the Tengger Desert, China. The desert seed bank was dominated by annual herbs. We found that more rainfall in the growing season increased the number of seeds in the soil seed bank, and that quadrats at relatively higher elevations had fewer seeds. The species composition had more similarity in the seed bank than in the aboveground vegetation, though the seed bank and aboveground vegetation did change synchronously due to the rapid propagation of annuals. Together, our findings suggest that the combined effects of environmental factors and plant life forms determine the species composition and size of soil seed banks in deserts. Thus, if degraded desert ecosystems are left to regenerate naturally, the lack of shrub and perennial herb seeds could crucially limit their restoration. Human intervention and management may have to be applied to enhance the seed abundance of longer-lived lifeforms in degraded deserts.

Putting the Tree Back into the Landscape

2011 ◽  
Author(s):  
David Beresford-Jones
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Keystone Species ◽  
South Coast ◽  
Desert Ecosystem ◽  
Landscape Changes ◽  
The South

This book began with the archaeology of the Ullujaya and Samaca basins of the lower Ica Valley on the south coast of Peru. The archaeological investigations described here were undertaken to answer the following questions. Were these basins ever significantly more productive and vegetated landscapes? If so, when and how did change take place, and why? And how did these ecological and landscape changes correlate with cultural ones? The second part of the book conducted a thorough review of the botanical and agroforestry literature, together with the researchers' own observations, on the ecological keystone species of the region, the huarango — a tree of the genus Prosopis — to show how important a role this genus plays in the desert ecosystem of the south coast of Peru. This concluding chapter seeks to achieve a synthesis between these two parts to offer answers to those aforementioned questions posed by today's austere landscape of the lower Ica Valley. In so doing, it proposes a model for geomorphological, ecological, and land-use changes through time for the basins of the lower Ica Valley. It also aims to relate this model to cultural trajectories.

scholarly journals Desert shrub stemflow and its significance in soil moisture replenishment

2011 ◽  
Vol 15 (2) ◽  
pp. 561-567 ◽  
Author(s):  
X.-P. Wang ◽  
Z.-N. Wang ◽  
R. Berndtsson ◽  
Y.-F. Zhang ◽  
Y.-X. Pan
Keyword(s):  
Soil Moisture ◽  
Soil Profile ◽  
Root Zone ◽  
Sand Dunes ◽  
Aluminum Foil ◽  
Time Domain Reflectometry ◽  
Desert Ecosystem ◽  
Desert Ecosystems ◽  
Caragana Korshinskii ◽  
Moisture Variation

Abstract. Stemflow of xerophytic shrubs represents a significant component of water replenishment to the soil-root system influencing water utilization of plant roots at the stand scale, especially in water scarce desert ecosystems. In this study, stemflow of Caragana korshinskii was quantified by an aluminum foil collar collection method on re-vegetated sand dunes of the Shapotou restored desert ecosystem in northwestern China. Time domain reflectometry probes were inserted horizontally at 20 different soil profile depths under the C. korshinskii shrub to monitor soil moisture variation at hourly intervals. Results indicated that 2.2 mm precipitation was necessary for the generation of stemflow for C. korshinskii. Stemflow averaged 8% of the gross precipitation and the average funnelling ratio was as high as 90. The soil moisture in the uppermost soil profile was strongly correlated with individual rainfall and the stemflow strengthened this relationship. Therefore, it is favourable for the infiltrated water redistribution in the deeper soil profile of the root zone. Consequently, stemflow contributes significantly to a positive soil moisture balance in the root zone and the replenishment of soil moisture at deeper soil layers. This plays an important role in plant survival and the general ecology of arid desert environments.

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