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Fill JM, Meadows I, Walker JL, Crandall RM, Kerrigan JL. Smut fungus (Langdonia walkerae) incidence is lower in two bunchgrass species (Aristida stricta and A. beyrichiana) after fires early in the year. AMERICAN JOURNAL OF BOTANY 2024; 111:e16286. [PMID: 38366863 DOI: 10.1002/ajb2.16286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 12/04/2023] [Accepted: 12/04/2023] [Indexed: 02/18/2024]
Abstract
PREMISE In frequently burned southeastern USA pine-grassland communities, wiregrass (Aristida stricta and A. beyrichiana) are dominant bunchgrasses whose flowers are infected during flowering by a smut fungus (Langdonia walkerae). We hypothesized that because prescribed fire timing affects wiregrass flowering patterns, it could affect smut incidence (occurrence of smut on plants) and severity of infection in inflorescences and spikelets. Because soil order could influence plant susceptibility, we hypothesized that these patterns would differ between soil orders. We hypothesized differences between species as representative of geographic variation in this ecosystem. METHODS We surveyed the incidence and severity of L. walkerae in wiregrass populations (85 populations at 14 sites) that had been prescription burned at different times during the previous year. We used binomial regressions to test whether incidence and severity differed by burn day, soil order, or species, with site as a random effect. RESULTS Fires that occurred in the winter were associated with significantly lower incidence than fires later in the year (as the months progressed into summer). Plants growing on Spodosol soils were significantly less likely to be infected than those on other soils. More variation in incidence, however, was explained by site, suggesting that site-specific characteristics were important. Smut severity in inflorescences and spikelets was greater overall in populations of A. stricta than in southern populations (A. beyrichiana). CONCLUSIONS Our findings indicate that fire timing and soil order affect L. walkerae incidence in wiregrass plants, but neither appears to be associated with greater severity. Patterns of smut infection are related to site history and geographic variation.
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Affiliation(s)
- Jennifer M Fill
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, FL, 32611
| | - Inga Meadows
- Department of Entomology and Plant Pathology, Mountain Research Station, North Carolina State University, Waynesville, NC, 28786
| | - Joan L Walker
- US Forest Service Southern Research Station, Clemson, SC, 29631
| | - Raelene M Crandall
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, FL, 32611
| | - Julia L Kerrigan
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29634
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Osburn ED, Moon C, Stephenson T, Kittipalawattanapol K, Jones M, Strickland MS, Lynch LM. Disturbance of eucalypt forests alters the composition, function, and assembly of soil microbial communities. FEMS Microbiol Ecol 2023; 99:fiad085. [PMID: 37481693 DOI: 10.1093/femsec/fiad085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/06/2023] [Accepted: 07/21/2023] [Indexed: 07/24/2023] Open
Abstract
Forest disturbance has well-characterized effects on soil microbial communities in tropical and northern hemisphere ecosystems, but little is known regarding effects of disturbance in temperate forests of the southern hemisphere. To address this question, we collected soils from intact and degraded Eucalyptus forests along an east-west transect across Tasmania, Australia, and characterized prokaryotic and fungal communities using amplicon sequencing. Forest degradation altered soil microbial community composition and function, with consistent patterns across soil horizons and regions of Tasmania. Responses of prokaryotic communities included decreased relative abundance of Acidobacteriota, nitrifying archaea, and methane-oxidizing prokaryotes in the degraded forest sites, while fungal responses included decreased relative abundance of some saprotrophic taxa (e.g. litter saprotrophs). Forest degradation also reduced network connectivity in prokaryotic communities and increased the importance of dispersal limitation in assembling both prokaryotic and fungal communities, suggesting recolonization dynamics drive microbial composition following disturbance. Further, changes in microbial functional groups reflected changes in soil chemical properties-reductions in nitrifying microorganisms corresponded with reduced NO3-N pools in the degraded soils. Overall, our results show that soil microbiota are highly responsive to forest degradation in eucalypt forests and demonstrate that microbial responses to degradation will drive changes in key forest ecosystem functions.
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Affiliation(s)
- Ernest D Osburn
- Department of Soil and Water Systems, University of Idaho, 875 Perimeter Dr. MS 2340, Moscow, ID 83844, USA
| | - Cooper Moon
- Department of Environmental Science, University of Idaho, 875 Perimeter Dr. MS 1139, Moscow, ID 83844, USA
| | - Torrey Stephenson
- Department of Soil and Water Systems, University of Idaho, 875 Perimeter Dr. MS 2340, Moscow, ID 83844, USA
| | - Kawinwit Kittipalawattanapol
- School of Natural Sciences, University of Tasmania, Life Sciences Building, Biological Sciences, Hobart, Tasmania 7001, Australia
| | - Menna Jones
- School of Natural Sciences, University of Tasmania, Life Sciences Building, Biological Sciences, Hobart, Tasmania 7001, Australia
| | - Michael S Strickland
- Department of Soil and Water Systems, University of Idaho, 875 Perimeter Dr. MS 2340, Moscow, ID 83844, USA
| | - Laurel M Lynch
- Department of Soil and Water Systems, University of Idaho, 875 Perimeter Dr. MS 2340, Moscow, ID 83844, USA
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Wang J, Xue L, Zhou L, Wei L, Hu S, Wu H, Zhang H, Xiang C, Li X. Cumulative ecosystem response to Hydraulic Engineering Infrastructure Projects in an arid basin. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159110. [PMID: 36191713 DOI: 10.1016/j.scitotenv.2022.159110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/24/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
Hydraulic Engineering Infrastructure Projects (HEIPs) typically show profound effects on hydrological systems and ecosystems. However, data restrictions have limited the exploration of the influences of compound HEIPs on ecosystems to a few studies. This study proposes a watershed-wide ecosystem assessment framework to investigate the impact of HEIPs in the Tarim River Headwaters-Hotan River Basin on the ecosystem of the arid zone. The framework includes a deep learning-meta cellular automata algorithm (DLMCAA) based on the spatiotemporal characteristics of HEIPs and hydro-meteorological and human activities. Moreover, the spatiotemporal relationships between compound HEIPs and ecosystem variances were quantified. The framework including DLMCAA showed a good performance in simulating landcover in 2020, with a Kappa coefficient of 0.89. Therefore, the DLMCAA could be used to simulate and predict ecosystem changes under the HEIPs, which suggested that the framework is effective and practical. An analysis of the spatiotemporal distribution of each ecosystem from 1980 to 2020 showed that the low shrub ecosystems changed most significantly (26.38 %) between 1980 and 2020. Also, the use of spatially driven hydrological project data from different ABC scenarios showed that ecosystems driven by HEIPs were more stable compared to those without HEIPs under future climate change. In particular, the DLMCAA indicated that compound HEIPs had a more positive impact on ecosystem oases in arid lands compared with that of single HEIPs. The results of this study can serve as a scientific reference for assessing the impact of HEIPs, as well as for understanding ecosystem changes and facilitating sustainable water resource management in the arid regions.
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Affiliation(s)
- Jing Wang
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, PR China
| | - Lianqing Xue
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, PR China; Wanjiang University of Technology, Anhui 243031, PR China.
| | - Liyong Zhou
- Xinjiang Institute of Water Resources and Hydropower Research, Urumqi 830009, PR China
| | - Linyong Wei
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, PR China
| | - Siwen Hu
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, PR China
| | - Hongshi Wu
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, PR China
| | - Hao Zhang
- College of Environment, Hohai University, Nanjing 210098, PR China
| | - Chenguang Xiang
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, PR China
| | - Xinghan Li
- Institute of Tropical Bioscience and Biotechnology, Hainan Key Laboratory of Functional Components and Utilization of Marine Biological Resources, Chinese Academy of Tropical Agricultural Science, Haikou 571101, PR China
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Sritharan MS, Scheele BC, Blanchard W, Foster CN, Werner PA, Lindenmayer DB. Plant rarity in fire-prone dry sclerophyll communities. Sci Rep 2022; 12:12055. [PMID: 35835789 PMCID: PMC9283327 DOI: 10.1038/s41598-022-15927-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 07/01/2022] [Indexed: 11/09/2022] Open
Abstract
Understanding the responses of rare species to altered fire disturbance regimes is an ongoing challenge for ecologists. We asked: are there associations between fire regimes and plant rarity across different vegetation communities? We combined 62 years of fire history records with vegetation surveys of 86 sites across three different dry sclerophyll vegetation communities in Booderee National Park, south-east Australia to: (1) compare associations between species richness and rare species richness with fire regimes, (2) test whether fire regimes influence the proportion of rare species present in an assemblage, and (3) examine whether rare species are associated with particular fire response traits and life history. We also sought to determine if different rarity categorisations influence the associations between fire regimes and plant rarity. We categorised plant rarity using three standard definitions; species' abundance, species' distribution, and Rabinowitz's measure of rarity, which considers a species' abundance, distribution and habitat specificity. We found that total species richness was negatively associated with short fire intervals but positively associated with time since fire and fire frequency in woodland communities. Total species richness was also positively associated with short fire intervals in forest communities. However, rare species richness was not associated with fire when categorised via abundance or distribution. Using Rabinowitz's measure of rarity, the proportion of rare species present was negatively associated with fire frequency in forest communities but positively associated with fire frequency in woodland communities. We found that rare species classified by all three measures of rarity exhibited no difference in fire response traits and serotiny compared to species not classified as rare. Rare species based on abundance differed to species not classified as rare across each life history category, while species rare by distribution differed in preferences for seed storage location. Our findings suggest that species categorised as rare by Rabinowitz's definition of rarity are the most sensitive to the effects of fire regimes. Nevertheless, the paucity of responses observed between rare species with fire regimes in a fire-prone ecosystem suggests that other biotic drivers may play a greater role in influencing the rarity of a species in this system.
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Affiliation(s)
- Meena S Sritharan
- Threatened Species Recovery Hub, Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia.
| | - Ben C Scheele
- Threatened Species Recovery Hub, Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia
| | - Wade Blanchard
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - Claire N Foster
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - Patricia A Werner
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - David B Lindenmayer
- Threatened Species Recovery Hub, Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia
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Lindenmayer DB, McBurney L, Blanchard W, Marsh K, Bowd E, Watchorn D, Taylor C, Youngentob K. Elevation, disturbance, and forest type drive the occurrence of a specialist arboreal folivore. PLoS One 2022; 17:e0265963. [PMID: 35417466 PMCID: PMC9007346 DOI: 10.1371/journal.pone.0265963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/10/2022] [Indexed: 11/19/2022] Open
Abstract
Quantifying the factors associated with the presence and abundance of species is critical for conservation. Here, we quantify the factors associated with the occurrence of the Southern Greater Glider in the forests of the Central Highlands of Victoria, south-eastern Australia. We gathered counts of animals along transects and constructed models of the probability of absence, and then the abundance if animals were present (conditional abundance), based on species' associations with forest type, forest age, the abundance of denning sites in large old hollow-bearing trees, climatic conditions, and vegetation density. We found evidence of forest type effects, with animals being extremely uncommon in Alpine Ash and Shining Gum forest. In Mountain Ash forest, we found a negative relationship between the abundance of hollow-bearing trees and the probability of Southern Greater Glider absence. We also found a forest age effect, with the Southern Greater Glider completely absent from the youngest sites that were subject to a high-severity, stand-replacing wildfire in 2009. The best fitting conditional abundance model for the Southern Greater Glider included a strong positive effect of elevation; the species was more abundant in Mountain Ash forests at higher elevations. Our study highlights the importance of sites with large old hollow-bearing trees for the Southern Greater Glider, although such trees are in rapid decline in Mountain Ash forests. The influence of elevation on conditional abundance suggests that areas at higher elevations will be increasingly important for the conservation of the species, except where Mountain Ash forest is replaced by different tree species that may be unsuitable for the Southern Greater Glider.
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Affiliation(s)
- David B. Lindenmayer
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - Lachlan McBurney
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - Wade Blanchard
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - Karen Marsh
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Elle Bowd
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - Darcy Watchorn
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Chris Taylor
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - Kara Youngentob
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
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Bowd E, Blanchard W, McBurney L, Lindenmayer D. Direct and indirect disturbance impacts on forest biodiversity. Ecosphere 2021. [DOI: 10.1002/ecs2.3823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Elle Bowd
- Fenner School of Environment and Society The Australian National University Canberra Australian Capital Territory 2601 Australia
| | - Wade Blanchard
- Fenner School of Environment and Society The Australian National University Canberra Australian Capital Territory 2601 Australia
| | - Lachlan McBurney
- Fenner School of Environment and Society The Australian National University Canberra Australian Capital Territory 2601 Australia
| | - David Lindenmayer
- Fenner School of Environment and Society The Australian National University Canberra Australian Capital Territory 2601 Australia
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7
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Bowd EJ, Banks SC, Bissett A, May TW, Lindenmayer DB. Disturbance alters the forest soil microbiome. Mol Ecol 2021; 31:419-447. [PMID: 34687569 DOI: 10.1111/mec.16242] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/24/2021] [Accepted: 10/11/2021] [Indexed: 12/21/2022]
Abstract
Billions of microorganisms perform critical below-ground functions in all terrestrial ecosystems. While largely invisible to the naked eye, they support all higher lifeforms, form symbiotic relationships with ~90% of terrestrial plant species, stabilize soils, and facilitate biogeochemical cycles. Global increases in the frequency of disturbances are driving major changes in the structure and function of forests. However, despite their functional significance, the disturbance responses of forest microbial communities are poorly understood. Here, we explore the influence of disturbance on the soil microbiome (archaea, fungi and bacteria) of some of the world's tallest and most carbon-dense forests, the Mountain Ash forests of south-eastern Australia. From 80 sites, we identified 23,277 and 19,056 microbial operational taxonomic units from the 0-10 cm and 20-30 cm depths of soil respectively. From this extensive data set, we found the diversity and composition of these often cryptic communities has been altered by human and natural disturbance events. For instance, the diversity of ectomycorrhizal fungi declined with clearcut logging, the diversity of archaea declined with salvage logging, and bacterial diversity and overall microbial diversity declined with the number of fires. Moreover, we identified key associations between edaphic (soil properties), environmental (slope, elevation) and spatial variables and the composition of all microbial communities. Specifically, we found that soil pH, manganese, magnesium, phosphorus, iron and nitrate were associated with the composition of all microbial communities. In a period of widespread degradation of global forest ecosystems, our findings provide an important and timely insight into the disturbance responses of soil microbial communities, which may influence key ecological functions.
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Affiliation(s)
- Elle J Bowd
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - Sam C Banks
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia.,College of Engineering, IT and the Environment, Research Institute for Environment and Livelihoods, Charles Darwin University, Darwin, NT, Australia
| | - Andrew Bissett
- The Commonwealth Scientific and Industrial Research Organization, CSIRO Oceans and Atmosphere, Hobart, TAS, Australia
| | - Tom W May
- Royal Botanic Gardens Victoria, Melbourne, VIC, Australia
| | - David B Lindenmayer
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
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