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Cui G, Pugnaire FI, Yang L, Zhao W, Ale R, Shen W, Luo T, Liang E, Zhang L. Shrub-mediated effects on soil nitrogen determines shrub-herbaceous interactions in drylands of the Tibetan Plateau. FRONTIERS IN PLANT SCIENCE 2023; 14:1137365. [PMID: 36844071 PMCID: PMC9950575 DOI: 10.3389/fpls.2023.1137365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
INTRODUCTION Shrub promotes the survival, growth and reproduction of understory species by buffering the environmental extremes and improving limited resources (i.e., facilitation effect) in arid and semiarid regions. However, the importance of soil water and nutrient availability on shrub facilitation, and its trend along a drought gradient have been relatively less addressed in water-limited systems. METHODS We investigated species richness, plant size, soil total nitrogen and dominant grass leaf δ13C within and outside the dominant leguminous cushion-like shrub Caragana versicolor along a water deficit gradient in drylands of Tibetan Plateau. RESULTS We found that C. versicolor increased grass species richness but had a negative effect on annual and perennial forbs. Along the water deficit gradient, plant interaction assessed by species richness (RIIspecies) showed a unimodal pattern with shift from increase to decrease, while plant interaction assessed by plant size (RIIsize) did not vary significantly. The effect of C. versicolor on soil nitrogen, rather than water availability, determined its overall effect on understory species richness. Neither the effect of C. versicolor on soil nitrogen nor water availability affected plant size. DISCUSSION Our study suggests that the drying tendency in association with the recent warming trends observed in drylands of Tibetan Plateau, will likely hinder the facilitation effect of nurse leguminous shrub on understories if moisture availability crosses a critical minimum threshold.
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Affiliation(s)
- Guangshuai Cui
- State Key Laboratory of Tibetan Plateau Earth System Science, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Almería, Spain
| | - Francisco I. Pugnaire
- Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Almería, Spain
| | - Liu Yang
- State Key Laboratory of Tibetan Plateau Earth System Science, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wanglin Zhao
- State Key Laboratory of Tibetan Plateau Earth System Science, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Rita Ale
- State Key Laboratory of Tibetan Plateau Earth System Science, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Wei Shen
- State Key Laboratory of Tibetan Plateau Earth System Science, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Tianxiang Luo
- State Key Laboratory of Tibetan Plateau Earth System Science, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Eryuan Liang
- State Key Laboratory of Tibetan Plateau Earth System Science, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Lin Zhang
- State Key Laboratory of Tibetan Plateau Earth System Science, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Institute of Science and Technology Information of Tibet Autonomous Region, Lhasa, China
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Michalet R, Nemer D, Delerue F. Canopy buffering effects against climatic extremes of deciduous broad‐leaved forests are higher on calcareous than siliceous bedrocks. OIKOS 2023. [DOI: 10.1111/oik.09755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Paradza VM, Khamis FM, Yusuf AA, Subramanian S, Akutse KS. Efficacy of Metarhizium anisopliae and ( E)-2-hexenal combination using autodissemination technology for the management of the adult greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae). FRONTIERS IN INSECT SCIENCE 2022; 2:991336. [PMID: 38646071 PMCID: PMC11027017 DOI: 10.3389/finsc.2022.991336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/24/2022] [Indexed: 04/23/2024]
Abstract
The efficiency of an autodissemination technique in controlling adult whiteflies, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae) on tomato, Solunum lycopersicum was investigated with previously identified potent fungal isolates of Metarhizium anisopliae ICIPE 18, ICIPE 62 and ICIPE 69 under screenhouse or semi-field conditions. The autodissemination device was inoculated with dry conidia of the M. anisopliae isolates, while control insects were exposed to a fungus-free device. Sampling for conidia uptake, conidial viability and persistence, and insect mortality was done at 1, 2, 3, 5 and 8 days post-exposure, and collected insects were monitored for mortality over ten days. Overall, mortality was higher in insects exposed to ICIPE 18 (62.8%) and ICIPE 69 (61.8%) than in those exposed to ICIPE 62 (42.6%), with median lethal times, (LT50) ranging between 6.73-8.54 days. The control group recorded the lowest mortality rates (18.9%). A general linear reduction in conidial viability with exposure time was observed, although this was more pronounced with M. anisopliae ICIPE 62. Insects exposed to M. anisopliae ICIPE 69 also recorded the highest conidia uptake, hence selected for further evaluation with a T. vaporariorum attractant volatile organic compound, (E)-2-hexenal. The volatile inhibited fungal germination in laboratory compatibility tests, therefore, spatial separation of M. anisopliae ICIPE 69 and (E)-2-hexenal in the autodissemination device was conducted. The inhibitory effects of the volatile were significantly reduced by spatial separation at a distance of 5 cm between the fungus and the volatile, which was found to be more suitable and chosen for the subsequent experiments. Results showed that (E)-2-hexenal did not influence conidia uptake by the insects, while fungal viability and the subsequent mortality variations were more related to duration of exposure. The fungus-volatile compatibility demonstrated with spatial separation provides a basis for the optimisation of the volatile formulation to achieve better T. vaporariorum suppression with an excellent autodissemination efficiency when used in the management of whiteflies under screenhouse conditions.
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Affiliation(s)
- Vongai M. Paradza
- Plant Health Theme, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa
| | - Fathiya M. Khamis
- Plant Health Theme, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Abdullahi A. Yusuf
- Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa
- Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Hatfield, South Africa
| | - Sevgan Subramanian
- Plant Health Theme, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Komivi S. Akutse
- Plant Health Theme, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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Nemer D, Michalet R, Randé H, Sappin‐Didier V, Delerue F. Higher facilitation for stress‐intolerant ecotypes along a metal pollution gradient are due to a decrease in performance in absence of neighbours. OIKOS 2022. [DOI: 10.1111/oik.09499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- David Nemer
- Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805 Pessac France
| | - Richard Michalet
- Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805 Pessac France
| | - Hugo Randé
- Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805 Pessac France
| | | | - Florian Delerue
- Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805 Pessac France
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