Business as usual: macrolichen community response to the resilience of spruce–fir forests to beetle disturbance in northwestern Colorado

Over the past few decades, spruce beetles (Dendroctonus rufipennis Kirby) have drastically altered spruce–fir forests in western North America. Past research has shown that forest conditions (i.e., canopy openings, amounts of coarse woody material) change after spruce beetle disturbance, but little work has studied the impacts of these changes on the resident biotic communities. Even less research has investigated how spruce beetle disturbance affects lichen communities, which we anticipated as benefiting them due to canopy opening and increased woody material availability. We studied macrolichen community structure, including abundance and community composition, and habitat characteristics in areas with significant spruce beetle damage, as first detected between 1996 and 2017 in northwestern Colorado. We found few habitat differences among beetle disturbance classes that reflected varying time since infestation, and only the most recently affected plots (2012–2017) had significantly different lichen community structure relative to other sampled areas. We observed that the spruce–fir forests within our study exhibited ecological resilience to beetle outbreaks, and we did not measure differences in the amount of canopy openings or amounts of coarse woody material. Subsequently, the lack of differential lichen community response was not surprising.

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Temporal trends in benthic macrofauna composition in response to seasonal variation in a tropical coastal lagoon, Celestun, Gulf of Mexico

Marine and Freshwater Research ◽

10.1071/mf07189 ◽

2008 ◽

Vol 59 (9) ◽

pp. 772 ◽

Cited By ~ 17

Author(s):

Norma A. Hernández-Guevara ◽

Daniel Pech ◽

Pedro-Luis Ardisson

Keyword(s):

Community Structure ◽

Coastal Lagoon ◽

Benthic Community ◽

Temporal Trends ◽

Community Response ◽

Benthic Macrofauna ◽

Habitat Characteristics ◽

Physical Factors ◽

Tropical Coastal Lagoon ◽

Habitat Variation

Aquatic habitats in some tropical coastal environments can change seasonally, causing changes in the community structure of the benthic macrofauna. A tropical coastal lagoon, the Celestun lagoon, on the north-west Yucatan peninsula, was sampled seasonally and faunal, water and sediment data were compared with conditions during the 1994–1995 weather cycle across a grid of 12 sites distributed along the lagoon’s salinity gradient. Habitat variation was expressed as physical factors associated with the water column (e.g. salinity) and bottom sediments (e.g. interstitial salinity, texture), whereas the benthic community response was assessed through changes in species composition, diversity and dominance. Taxonomic dominance varied according to changes in seasonal habitat characteristics. During the season of strong northerly winds (‘nortes’), molluscs dominated and polychaetes almost disappeared. Polychaetes then recovered during the dry season, becoming as common as crustaceans and molluscs. Finally, during the rainy season, polychaetes became the dominant group and molluscs declined. A conceptual model summarising the community structure changes associated with key physical and biotic factors is proposed. The results indicate that the benthic community of the Celestun lagoon is a resilient one, largely driven by natural weather variability in this tropical ecosystem to a greater extent than previously suggested.

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Lichen Community Response to Prescribed Burning and Thinning in Southern Pine Forests of the Mid-Atlantic Coastal Plain, USA

Fire Ecology ◽

10.4996/fireecology.1103014 ◽

2015 ◽

Vol 11 (3) ◽

pp. 14-33 ◽

Cited By ~ 10

Author(s):

David G. Ray ◽

Jason W. Barton ◽

James C. Lendemer

Keyword(s):

Coastal Plain ◽

Prescribed Burning ◽

Community Response ◽

Atlantic Coastal Plain ◽

Pine Forests ◽

Southern Pine ◽

Lichen Community ◽

Atlantic Coastal

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Associations among land-use, habitat characteristics, and invertebrate community structure in nine streams on the island of Oahu, Hawaii

10.3133/wri034256 ◽

2003 ◽

Keyword(s):

Land Use ◽

Community Structure ◽

Habitat Characteristics ◽

Invertebrate Community ◽

Invertebrate Community Structure

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Zooplankton Community Response to Seasonal Hypoxia: A Test of Three Hypotheses

Diversity ◽

10.3390/d12010021 ◽

2020 ◽

Vol 12 (1) ◽

pp. 21 ◽

Cited By ~ 2

Author(s):

Julie E. Keister ◽

Amanda K. Winans ◽

BethElLee Herrmann

Keyword(s):

Community Structure ◽

Puget Sound ◽

Temporal Stability ◽

Zooplankton Community ◽

Community Response ◽

Crustacean Zooplankton ◽

Zooplankton Abundance ◽

Calanoid Copepods ◽

Low Oxygen ◽

Seasonal Hypoxia

Several hypotheses of how zooplankton communities respond to coastal hypoxia have been put forward in the literature over the past few decades. We explored three of those that are focused on how zooplankton composition or biomass is affected by seasonal hypoxia using data collected over two summers in Hood Canal, a seasonally-hypoxic sub-basin of Puget Sound, Washington. We conducted hydrographic profiles and zooplankton net tows at four stations, from a region in the south that annually experiences moderate hypoxia to a region in the north where oxygen remains above hypoxic levels. The specific hypotheses tested were that low oxygen leads to: (1) increased dominance of gelatinous relative to crustacean zooplankton, (2) increased dominance of cyclopoid copepods relative to calanoid copepods, and (3) overall decreased zooplankton abundance and biomass at hypoxic sites compared to where oxygen levels are high. Additionally, we examined whether the temporal stability of community structure was decreased by hypoxia. We found evidence of a shift toward more gelatinous zooplankton and lower total zooplankton abundance and biomass at hypoxic sites, but no clear increase in the dominance of cyclopoid relative to calanoid copepods. We also found the lowest variance in community structure at the most hypoxic site, in contrast to our prediction. Hypoxia can fundamentally alter marine ecosystems, but the impacts differ among systems.

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Effects of a Transmission Line on Bird Populations in the Red Lake Peatland, Northern Minnesota

The Auk ◽

10.1093/auk/101.3.487 ◽

1984 ◽

Vol 101 (3) ◽

pp. 487-498 ◽

Cited By ~ 4

Author(s):

Gerald J. Niemi ◽

JoAnn M. Hanowski

Keyword(s):

Transmission Line ◽

Habitat Structure ◽

Breeding Population ◽

Habitat Characteristics ◽

Population Densities ◽

Yearly Variation ◽

Bird Populations ◽

Census Methods ◽

Habitat Differences ◽

Transect Counts

Abstract The effects of a 500-kV transmission line on bird populations were assessed by comparing paired treatment areas [which included a transmission line and right-of-way (ROW)] with similar control areas in six different habitat types during the breeding and migration seasons. Habitat structure was measured to examine the inherent differences between control and treatment areas. Using two census methods, territorial mapping and transect counts, we determined that Sedge Wrens and LeConte's Sparrows had lower breeding-population densities in treatment areas than in control areas. LeConte's Sparrows and Connecticut Warblers occurred at greater mean distances from the transmission line in treatment areas than from a similarly positioned line in control areas. Fifteen paired t-tests (five habitats in 3 yr), in which territorial mapping data were used, revealed that community densities were lower in one treatment habitat (high shrub) in 1 of 3 yr (P < 0.05). A two-way analysis of variance with transect counts, however, was not confirmatory when yearly variation was included. Transect counts revealed lower population densities in one treatment habitat (low shrub) in 2 of 3 yr (P < 0.05). In contrast, we observed greater species richness (P < 0.05) in two treatment habitats (closed spruce and sedge fen) than in controls. Treatment habitats were most similar in habitat structure to their paired control habitats, but each habitat of the pair was significantly different (P < 0.05) from the other in at least 2 of 10 habitat characteristics analyzed. We suggest that the avian differences observed between paired areas were primarily attributable to (1) the inherent habitat differences between control and treatment areas, and (2) the new habitat created under the transmission line. Our data indicated negligible effects of this transmission line on bird populations, but interpretations are difficult, because the effects varied with (1) habitat, (2) season, and (3) method considered. Postimpact studies, which compare control and treatment areas, are less effective than before-and-after studies, because differences in habitat structure exist between any two areas.

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Nest Site Selection and Nesting Success in Saltmarsh Breeding Sparrows: The Importance of Nest Habitat, Timing, and Study Site Differences

The Condor ◽

10.1093/condor/107.4.849 ◽

2005 ◽

Vol 107 (4) ◽

pp. 849-862 ◽

Cited By ~ 9

Author(s):

Carina Gjerdrum ◽

Chris S. Elphick ◽

Margaret Rubega

Keyword(s):

Site Selection ◽

Nest Site ◽

Nesting Success ◽

Nest Site Selection ◽

Habitat Characteristics ◽

Smooth Cordgrass ◽

Vegetation Model ◽

Nest Habitat ◽

Habitat Differences ◽

Seaside Sparrow

Abstract We examined nest-site selection and nesting success in Saltmarsh Sharp-tailed (Ammodramus caudacutus) and Seaside Sparrows (A. maritimus), at seven sites in Connecticut. We found 160 Saltmarsh Sharp-tailed Sparrow nests and 23 Seaside Sparrow nests, and compared characteristics of their locations to each other and to random locations. We tracked success of all nests, quantified nest productivity and causes of nest losses, and tested for habitat differences between successful and unsuccessful nests. Saltmarsh Sharp-tailed Sparrows nested in higher than average locations, where the vegetation was taller and more dense than at random locations, where there was a deep layer of thatch, and where saltmeadow cordgrass (Spartina patens) dominated the vegetation. There was little evidence that habitat characteristics influenced the success of nesting birds, but the timing of nest initiation relative to spring tides was important. Seaside Sparrow nests occurred in even taller vegetation, that was more sparse than average and dominated by the tall form of smooth cordgrass (S. alterniflora). Habitat influenced the success of Seaside Sparrow nests, but timing did not; on average, successful nests occurred in taller vegetation. Model comparisons suggest that vegetation structure influences site selection more than species composition or inherent differences among marshes. Overall, our results indicate that nest flooding is a major threat to successful reproduction in both species, but they have different strategies to avoid flooding. Saltmarsh Sharp-tailed Sparrows time their reproduction to avoid especially high tides, while Seaside Sparrows avoid flooding spatially by nesting in tall vegetation.

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Effects of Phytoremediation Treatment on Bacterial Community Structure and Diversity in Different Petroleum-Contaminated Soils

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph15102168 ◽

2018 ◽

Vol 15 (10) ◽

pp. 2168 ◽

Cited By ~ 9

Author(s):

Yuanyuan Shen ◽

Yu Ji ◽

Chunrong Li ◽

Pingping Luo ◽

Wenke Wang ◽

...

Keyword(s):

Community Structure ◽

Bacterial Community ◽

Contaminated Soils ◽

Bacterial Community Structure ◽

High Throughput Sequencing ◽

Cost Effective ◽

Northwest China ◽

Community Response ◽

Available Nitrogen ◽

Increased Risk

Increased exploitation and use of petroleum resources is leading to increased risk of petroleum contamination of soil and groundwater. Although phytoremediation is a widely-used and cost-effective method for rehabilitating soils polluted by petroleum, bacterial community structure and diversity in soils undergoing phytoremediation is poorly understood. We investigate bacterial community response to phytoremediation in two distinct petroleum-contaminated soils (add prepared petroleum-contaminated soils) from northwest China, Weihe Terrace soil and silty loam from loess tableland. High-throughput sequencing technology was used to compare the bacterial communities in 24 different samples, yielding 18,670 operational taxonomic units (OTUs). The dominant bacterial groups, Proteobacteria (31.92%), Actinobacteria (16.67%), Acidobacteria (13.29%) and Bacteroidetes (6.58%), increased with increasing petroleum concentration from 3000 mg/kg–10,000 mg/kg, while Crenarchaeota (13.58%) and Chloroflexi (4.7%) decreased. At the order level, RB41, Actinomycetales, Cytophagales, envOPS12, Rhodospirillales, MND1 and Xanthomonadales, except Nitrososphaerales, were dominant in Weihe Terrace soil. Bacterial community structure and diversity in the two soils were significantly different at similar petroleum concentrations. In addition, the dominant genera were affected by available nitrogen, which is strongly associated with the plants used for remediation. Overall, the bacterial community structure and diversity were markedly different in the two soils, depending on the species of plants used and the petroleum concentration.

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Effects of proximity to urban areas on a riparian bird community in remnant Atlantic Forest in southeastern Brazil

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2313 ◽

2019 ◽

Vol 14 (7) ◽

pp. 1

Author(s):

Ana Cecília de Paula Lourenço ◽

Maria Cecília Barbosa de Toledo

Keyword(s):

Urban Areas ◽

Riparian Forest ◽

Bird Species ◽

Bird Community ◽

Habitat Characteristics ◽

Southeastern Brazil ◽

Average Height ◽

Trophic Groups ◽

Generalist Species ◽

Canopy Opening

The goal of this study was to evaluate the effect of urban activities on the structure and composition of a bird community in riparian forests in the state of São Paulo, Brazil. The study was carried out in seven areas of remnant riparian forest where fixed points have been established to sample bird species. Richness, diversity, abundance, frequency and trophic groups were used as metrics of the bird community. At each point measurements were taken for: (1) habitat characteristics: average height of trees, number of trees above 2m, number of shrubs <2m and the percentage of canopy opening; (2) neighborhood characteristics: closest distance from open areas, highways, urban areas, river and floodplain to the point of observation. The observations resulted in 88 species of birds belonging to 34 families. The most representative families were Tyrannidae, Thraupidae and Picidae. The most predominant trophic groups were insectivorous (54%), omnivorous (11.5%) and frugivorous (10.3%). The results obtained showed that the number of trees explained the variation in abundance, while the mean height of the trees explained variations in richness and frequency. Overall, the bird community was negatively affected by proximity of urban areas and highways. In conclusion, the community of birds in the riparian forest may be affected by the loss of trees above 2m and by urbanization, leading mainly to the replacement of species belonging to specialist trophic groups by generalist species and those more adjusted to human presence.

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HABITAT CHARACTERISTICS AND GRASSHOPPER COMMUNITY DYNAMICS ON MIXED-GRASS RANGELAND

The Canadian Entomologist ◽

10.4039/ent12389-1 ◽

1991 ◽

Vol 123 (1) ◽

pp. 89-105 ◽

Cited By ~ 17

Author(s):

Mark A. Quinn ◽

R.L. Kepner ◽

D.D. Walgenbach ◽

R.A. Bohls ◽

P.D. Pooler ◽

...

Keyword(s):

Community Structure ◽

Community Dynamics ◽

Detrended Correspondence Analysis ◽

Bouteloua Gracilis ◽

Community Change ◽

Habitat Characteristics ◽

Agropyron Smithii ◽

Spatial Gradients ◽

Mixed Grass ◽

The Difference

AbstractA study was conducted in Butte County of western South Dakota to determine the relationships between habitat characteristics and spatial and temporal changes in community structure of grasshoppers on mixed-grass rangeland. Detrended correspondence analysis (DCA) of 29 undisturbed grasshopper communities and correlation analysis of DCA axis values and habitat variables denned specific spatial gradients underlying the community structure of grasshoppers. Results indicated that grasshopper communities changed along a primary gradient of percentage of coverage of grasses, particularly Buchloe dactyloides (Nutt.) Engelm., and a secondary gradient of percentage composition of clay and sand in the soil.DCA of 24 grasshopper communities sampled in 1986 and 1987, multiple regression analysis, and factor analysis were used to determine the relationships between specific habitat characteristics and changes in communities of grasshoppers treated with either a nonselective insecticidal spray (malathion) or a selective insecticidal bait (bran bait with carbaryl). Results indicated that between-year change in community composition, or the difference between post-treatment communities in 1986 and 1987, was positively correlated with percentage of coverage of total grasses and forbs. Community malleability, defined as the tendency of a community to return to its predisturbed state, was greater in habitats with high coverages of Agropyron smithii Rydb. and Carex spp., low coverage of Bouteloua gracilis (H.B.K.) Lag. ex Steud., and low species richness of grasses. Our results emphasize the importance of habitat characteristics in structuring undisturbed grasshopper communities and in community change after perturbation with insecticides.

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