Restoration for Resistance to Invasion by Giant Reed (Arundo donax)

2009 ◽  
Vol 2 (4) ◽  
pp. 279-291 ◽  
Author(s):  
Lauren D. Quinn ◽  
Jodie S. Holt

AbstractThe relationship between plant community composition and invasibility has been studied extensively but seldom in the context of ecosystem restoration. Experimental riparian restoration plots differing in species composition and density were established and evaluated for susceptibility to invasion by giant reed, a common riparian invader in California, and natural recruitment by riparian species over time. Plots were planted in 2002 with cuttings of common threesquare (a sedge), seepwillow (a shrub), and Goodding's willow (a tree) at two densities in monoculture and all possible mixture combinations. Giant reed rhizomes were introduced into half of the plots in the spring of 2003, while the remaining plots were allowed to undergo natural recruitment for an additional year. In late winter 2004, giant reed rhizomes were planted in the remaining plots. Both planting groups were followed for one growing season to evaluate giant reed establishment, survival, and growth. Community composition affected giant reed performance, particularly in 2003 before natural recruitment occurred. In that year, plots containing seepwillow + willow had the lowest giant reed shoot production, growth, and survival. All plots containing seepwillow were resistant to colonization by natural recruitment in 2004, but none of the planting treatments affected giant reed success in that year. Giant reed was more successful overall in 2004 despite deeper shade and drier soils. This pattern could be attributed to larger initial rhizome size in 2004, which allowed giant reed to overcome environmental stress during establishment. Planting density did not impact giant reed or natural recruitment independently, but may affect environmental parameters and warrants further study as a potential contributor to restoration success. Our results indicate that choice of species composition in restoration might impact giant reed invasion success initially, but community resistance might not be sustainable and maintenance-free over time.

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Alison C. Bartenslager ◽  
Nirosh D. Althuge ◽  
John Dustin Loy ◽  
Matthew M. Hille ◽  
Matthew L. Spangler ◽  
...  

Abstract Background Infectious Bovine Keratoconjunctivitis (IBK), commonly known as pinkeye, is one of the most significant diseases of beef cattle. As such, IBK costs the US beef industry at least 150 million annually. However, strategies to prevent IBK are limited, with most cases resulting in treatment with antibiotics once the disease has developed. Longitudinal studies evaluating establishment of the ocular microbiota may identify critical risk periods for IBK outbreaks or changes in the microbiota that may predispose animals to IBK. Results In an attempt to characterize the establishment and colonization patterns of the bovine ocular microbiota, we conducted a longitudinal study consisting of 227 calves and evaluated the microbiota composition over time using amplicon sequence variants (ASVs) based on 16S rRNA sequencing data and culture-based approaches. Beef calves on trial consisted of both male (intact) and females. Breeds were composed of purebred Angus and composites with varying percentages of Simmental, Angus, and Red Angus breeds. Average age at the start of the trial was 65 days ±15.02 and all calves remained nursing on their dam until weaning (day 139 of the study). The trial consisted of 139 days with four sampling time points on day 0, 21, 41, and 139. The experimental population received three different vaccination treatments (autogenous, commercial (both inactivated bacteria), and adjuvant placebo), to assess the effectiveness of different vaccines for IBK prevention. A significant change in bacterial community composition was observed across time periods sampled compared to the baseline (p < 0.001). However, no treatment effect of vaccine was detected within the ocular bacterial community. The bacterial community composition with the greatest time span between sampling time periods (98d span) was most similar to the baseline sample collected, suggesting re-establishment of the ocular microbiota to baseline levels over time after perturbation. The effect of IgA levels on the microbial community was investigated in a subset of cattle within the study. However, no significant effect of IgA was observed. Significant changes in the ocular microbiota were identified when comparing communities pre- and post-clinical signs of IBK. Additionally, dynamic changes in opportunistic pathogens Moraxella spp. were observed and confirmed using culture based methods. Conclusions Our results indicate that the bovine ocular microbiota is well represented by opportunistic pathogens such as Moraxella and Mycoplasma. Furthermore, this study characterizes the diversity of the ocular microbiota in calves and demonstrates the plasticity of the ocular microbiota to change. Additionally, we demonstrate the ocular microbiome in calves is similar between the eyes and the perturbation of one eye results in similar changes in the other eye. We also demonstrate the bovine ocular microbiota is slow to recover post perturbation and as a result provide opportunistic pathogens a chance to establish within the eye leading to IBK and other diseases. Characterizing the dynamic nature of the ocular microbiota provides novel opportunities to develop potential probiotic intervention to reduce IBK outbreaks in cattle.


Crustaceana ◽  
2014 ◽  
Vol 87 (8-9) ◽  
pp. 1095-1123 ◽  
Author(s):  
Laurent Decrouy ◽  
Torsten W. Vennemann

Because environmental conditions within a given basin are different for each season and at different water depth, knowledge of the life history and depth distribution of target species is important for environmental and palaeoenvironmental interpretations based on ostracod species assemblages and/or the geochemical compositions of their valves. In order to determine the distribution of species with depth as well as the life history of species from Lake Geneva, a one-year sampling campaign of living ostracods was conducted at five sites (2, 5, 13, 33 and 70 m water depth) on a monthly basis in the Petit-Lac (western basin of Lake Geneva, Switzerland). Based on the results, the different species can be classified into three groups. Littoral taxa are found at 2 and 5 m water depth and include, in decreasing numbers of individuals,Cypridopsis vidua(O. F. Müller, 1776),Pseudocandona compressa(Koch, 1838),Limnocythere inopinata(Baird, 1843),Herpetocypris reptans(Baird, 1835),Potamocypris smaragdina(Vávra, 1891),Potamocypris similis(G. W. Müller, 1912),Plesiocypridopsis newtoni(Brady & Robertson, 1870),Prionocypris zenkeri(Chyzer & Toth, 1858) andIlyocyprissp. Brady & Norman, 1889. Sublittoral species are found in a majority at 13 m water depth and to a lesser extend at 33 m water depth and include, in decreasing numbers of individuals,Fabaeformiscandona caudata(Kaufmann, 1900),Limnocytherina sanctipatricii,Candona candida(O. F. Müller, 1776) andIsocypris beauchampi(Paris, 1920). Profundal species are found equally at 13, 33 and 70 m water depth and includes, in decreasing numbers of individuals,Cytherissa lacustris(Sars, 1863),Candona neglectaSars, 1887 andCypria lacustrisLilljeborg, 1890. The occurrence ofLimnocytherina sanctipatricii(Brady & Robertson, 1869) is restricted from late winter to late spring when temperatures are low, whileC. vidua,L. inopinata,P. smaragdina,P. similis,P. newtoniandIlyocyprissp. occur predominantly from spring to early autumn when temperatures are high. Individuals ofC. neglecta,C. candida,F. caudata,P. compressa,C. lacustris,H. reptansandCp. lacustrisoccur throughout the year with juveniles and adults occurring during the same period (C. neglectaat 70 m,C. lacustrisat 13, 33 and 70 m, andH. reptansat 2, 5 and 13 m water depth) or with juveniles occurring during a different period of the year than adults (C. neglectaat 13 and 33 m andC. candida,F. caudataandP. compressaat their respective depth of occurrence). Among the environmental parameters investigated, an estimate of the relationship between ostracod autoecology and environmental parameters suggests that in the Petit-Lac: (i) water temperature and substrate characteristics are important factors controlling the distribution of species with depth, (ii) water temperature is also important for determining the timing of species development and, hence, its specific life history, and (iii) water oxygen and sedimentary organic matter content is less important compared to the other environmental parameter monitored.


2021 ◽  
Vol 11 ◽  
Author(s):  
Janneke Schreuder ◽  
Francisca C. Velkers ◽  
Alex Bossers ◽  
Ruth J. Bouwstra ◽  
Willem F. de Boer ◽  
...  

Associations between animal health and performance, and the host’s microbiota have been recently established. In poultry, changes in the intestinal microbiota have been linked to housing conditions and host development, but how the intestinal microbiota respond to environmental changes under farm conditions is less well understood. To gain insight into the microbial responses following a change in the host’s immediate environment, we monitored four indoor flocks of adult laying chickens three times over 16 weeks, during which two flocks were given access to an outdoor range, and two were kept indoors. To assess changes in the chickens’ microbiota over time, we collected cloacal swabs of 10 hens per flock and performed 16S rRNA gene amplicon sequencing. The poultry house (i.e., the stable in which flocks were housed) and sampling time explained 9.2 and 4.4% of the variation in the microbial community composition of the flocks, respectively. Remarkably, access to an outdoor range had no detectable effect on microbial community composition, the variability of microbiota among chickens of the same flock, or microbiota richness, but the microbiota of outdoor flocks became more even over time. Fluctuations in the composition of the microbiota over time within each poultry house were mainly driven by turnover in rare, rather than dominant, taxa and were unique for each flock. We identified 16 amplicon sequence variants that were differentially abundant over time between indoor and outdoor housed chickens, however none were consistently higher or lower across all chickens of one housing type over time. Our study shows that cloacal microbiota community composition in adult layers is stable following a sudden change in environment, and that temporal fluctuations are unique to each flock. By exploring microbiota of adult poultry flocks within commercial settings, our study sheds light on how the chickens’ immediate environment affects the microbiota composition.


2016 ◽  
Vol 50 (5) ◽  
pp. 387-394
Author(s):  
S. A. Kudrenko

Abstract The data about the community composition, number and biomass of amphipods in three gulfs of the North-Western Black Sea are presented. The amphipod communities of the gulfs of Yahorlyk, Karkinit, and Tendra were studied and the species composition was compared with the previously published data. For each particular gulf, the list of amphipod species was composed. The quantitative parameters of the amphipod communities in the studied localities in different years were described.


Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 187 ◽  
Author(s):  
Norma Martínez-Lendech ◽  
Ana P. Martínez-Falcón ◽  
Juan Jacobo Schmitter-Soto ◽  
Humberto Mejía-Mojica ◽  
Valentino Sorani-Dalbón ◽  
...  

Species introductions and extirpations are key aspects of aquatic ecosystem change that need to be examined at large geographic and temporal scales. The Pánuco Basin (Eastern Mexico) has high ichthyological diversity and ecological heterogeneity. However, freshwater fish (FWF) introductions and extirpations since the mid-1900s have modified species range and distribution. We examine changes in FWF species composition in and among four sub-basins of the Pánuco by comparing fish collection records pre-1980 to 2018. Currently, the FWF of the Pánuco includes 95 species. Fishes in the Poeciliidae, Cyprinidae, and Cichlidae, respectively, comprised most records over time. Significant differences in species composition were found between the first (pre-1980) and last (2011–2018) study periods, but not for periods in-between. Eight independent species groups were key for explaining changes in Pánuco river ichthyofauna; one group was dominated by invasive species, and saw increases in the number of records across study periods (faunal homogenization). Another group was formed by species with conservation concern with a declining number of records over time. Thirteen (2 native and 11 non-native) species were responsible for temporal turnover. These results strongly suggest high rates of differentiation over time (via native species loss) following widespread non-native species introductions.


2019 ◽  
Vol 24 (6) ◽  
pp. 992-997 ◽  
Author(s):  
Hulya Dizlek ◽  
Mehmet Karagoz ◽  
Farid Faraji ◽  
Ibrahim Cakmak

This study was conducted to determine mite species in dried figs in Aydin, Turkey between August 2014 and November 2016. A total of 141 dried fig samples were taken from producers’ storage, commercial storages and fig processing factories in Buharkent, Germencik, Incirliova, Kocarli, Kosk, Kuyucak, Merkez, Nazilli, Sultanhisar and Yenipazar districts. In addition, 24 dried fig samples were kept in storage for 8 months and the changes in mite species composition and their densities in stored figs were determined. As a result, 8 mite species belonging to 3 orders and 5 families were identified from the dried figs. Acarus siro L., Carpoglyphus lactis (L.), Glycyphagus destructor (Schrank), G. domesticus (De Geer) and Tyrophagus putrescentiae (Schrank) as pest species, and Blattisocius tarsalis (Berlese), B. mali (Oudemans) and Cheyletus eruditus (Schrank) as predatory mite species were found. Out of 141 samples, 133 were infested with mites and the infestation ratio was 94.3%. Tyrophagus putrescentiae was the most common pest species with an infestation rate of 72.3%, followed by C. lactis with 34.8%, A. siro, G. destructor and G. domesticus with 0.7% contamination, respectively. Carpoglyphus lactis was found to have the highest density with 10,488 individuals/kg in contaminated fig samples. Blattisocius tarsalis was the most common predatory mite species with an infestation rate of 77.3%. Blattisocius mali and C. eruditus were found in 9.2% and 4.3% of dried figs, respectively. This study showed that the dried fig samples kept in storage were always vulnerable to contamination with mites. Mite species composition and their densities also fluctuated over time.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Malinowski ◽  
M. Alawi ◽  
I. Krohn ◽  
S. Ruff ◽  
D. Indenbirken ◽  
...  

Abstract The community composition of betaproteobacterial ammonia-oxidizing bacteria (ß-AOB) in the River Elbe Estuary was investigated by high throughput sequencing of ammonia monooxygenase subunit A gene (amoA) amplicons. In the course of the seasons surface sediment samples from seven sites along the longitudinal profile of the upper Estuary of the Elbe were investigated. We observed striking shifts of the ß-AOB community composition according to space and time. Members of the Nitrosomonas oligotropha-lineage and the genus Nitrosospira were found to be the dominant ß-AOB within the river transect, investigated. However, continuous shifts of balance between members of both lineages along the longitudinal profile were determined. A noticeable feature was a substantial increase of proportion of Nitrosospira-like sequences in autumn and of sequences affiliated with the Nitrosomonas marina-lineage at downstream sites in spring and summer. Slightly raised relative abundances of sequences affiliated with the Nitrosomonas europaea/Nitrosomonas mobilis-lineage and the Nitrosomonas communis-lineage were found at sampling sites located in the port of Hamburg. Comparisons between environmental parameters and AOB-lineage (ecotype) composition revealed promising clues that processes happening in the fluvial to marine transition zone of the Elbe estuary are reflected by shifts in the relative proportion of ammonia monooxygenase sequence abundance, and hence, we propose ß-AOB as appropriate indicators for environmental dynamics and the ecological condition of the Elbe Estuary.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Waseem Abbas ◽  
Jeremy T. Howard ◽  
Henry A. Paz ◽  
Kristin E. Hales ◽  
James E. Wells ◽  
...  

Abstract In light of recent host-microbial association studies, a consensus is evolving that species composition of the gastrointestinal microbiota is a polygenic trait governed by interactions between host genetic factors and the environment. Here, we investigated the effect of host genetic factors in shaping the bacterial species composition in the rumen by performing a genome-wide association study. Using a common set of 61,974 single-nucleotide polymorphisms found in cattle genomes (n = 586) and corresponding rumen bacterial community composition, we identified operational taxonomic units (OTUs), Families and Phyla with high heritability. The top associations (1-Mb windows) were located on 7 chromosomes. These regions were associated with the rumen microbiota in multiple ways; some (chromosome 19; position 3.0–4.0 Mb) are associated with closely related taxa (Prevotellaceae, Paraprevotellaceae, and RF16), some (chromosome 27; position 3.0–4.0 Mb) are associated with distantly related taxa (Prevotellaceae, Fibrobacteraceae, RF16, RFP12, S24-7, Lentisphaerae, and Tenericutes) and others (chromosome 23; position 0.0–1.0) associated with both related and unrelated taxa. The annotated genes associated with identified genomic regions suggest the associations observed are directed toward selective absorption of volatile fatty acids from the rumen to increase energy availability to the host. This study demonstrates that host genetics affects rumen bacterial community composition.


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