DOI: 10.25338/b8p92j
title: Spatio-temporal dynamics of insect communities in constructed and natural tidal marshes with distinct landscape positions

description: Recovery of species richness, community composition, and biogeochemistry
 in restored wetlands often fails to reach levels of reference wetlands.
 While the effects of restoration on plant and non-insect macroinvertebrate
 communities are relatively well-studied, much less is known about the
 impacts of restoration on insect communities in wetlands. The aim of this
 research was to determine if previously observed differences in biological
 structure between one reference and two constructed J.
 roemerianus-dominated tidal marshes extend to their insect communities.
 Sampling methods included pan trapping, line-transect netting, floral
 observations, floral clippings, and light trapping. All insect taxa and
 functional groups were identified to the lowest taxonomic level possible
 monthly from April – October 2021 and analyzed for taxa richness,
 abundance, and H′ diversity. Floral density and herbivory scars on J.
 roemerianus shoots were also measured during flowering and peak growing
 season, respectively. Results indicated that the reference marsh supported
 a more diverse insect community than the constructed marshes, although
 insect abundance and taxa richness were similar among sites. Additionally,
 temporal shifts in community composition, based on relative abundances of
 insect taxa and functional feeding groups, differed among marshes, likely
 reflecting differences in habitats in the surrounding landscapes of each
 site. By assessing the structural differences in insect communities
 between reference and constructed marshes, we can further understand the
 community composition of an understudied group of organisms, potentially
 improve restoration strategies, and support the health of tidal marshes.
description: <strong><em>Study Site
 Description</em></strong>
 <em> </em>The study sites included one reference
 (i.e., natural) tidal marsh (NAT, -88.160’ N, 30.368’ W) and two
 34-year-old, constructed tidal marshes (CON-1, -88.152’N, 30.368’W, and
 CON-2, -88.151’ N, 30.367’ W) located near the mouth of the West Fowl
 River in Mobile County, AL, U.S.A . All three marshes are located within 1
 km of each other, with NAT directly connected to West Fowl River and CON-1
 and CON-2 hydrologically connected to NAT via a canal created at the time
 of marsh construction. All three sites experience diurnal microtides of
 approximately 0.26 m. The two constructed marshes were built in 1987 as a
 mitigation site through the harvesting and excavation of pine savannah in
 long, parallel strips that lowered the elevation to near sea level. After
 the initial excavation of the sites, canals were created though the center
 of each marsh to connect them to the main canal, which links to a tidal
 creek originating in the natural marsh. The canals and tidal creeks in
 these marshes are lined with a narrow (&lt; 1 m) band of <em>S.
 alterniflora</em><em>, </em>but the marsh platforms of
 all three marshes are dominated by <em>J. roemerianus</em>.
 The platform at NAT also contains an assemblage of other salt marsh
 plants, such as <em>S. alterniflora, S. patens </em>and
 <em>Distichlis spicata </em>as<em>
 </em>sub-dominates (Fromenthal, pers.
 obs.)<em>.</em> Previous studies at these
 sites demonstrated that NAT and CON marshes differ in their biological
 structure and ecosystem function. For instance, NAT had greater above- and
 belowground plant biomass, more soil organic matter and carbon content,
 and higher rates of denitrification and dissimilatory nitrate reduction to
 ammonium (DNRA) than CON marshes, although fluxes of carbon dioxide were
 similar between plots with similar vegetative cover in NAT and CON
 marshes. These observed differences in biogeochemical pathways may affect
 nutrient stocks and the palatability and quality of plant biomass. Changes
 in soil chemistry can also affect the timing and intensity of flowering in
 salt marsh plants. Therefore, these sites were deemed appropriate
 locations in which to examine whether observed differences in their plant
 community structure, soils, and nutrient processing rates translate into
 observed differences in insect communities. 
 <strong><em>Insect
 Sampling</em></strong>
 <em> </em>To compare insect communities between
 reference and constructed marshes, we conducted insect surveys in randomly
 selected <em>J. roemerianus </em>stands at each marsh over the
 plant growing season (April – September 2021). Four replicate quadrats
 (approximately 10 m<sup>2</sup>) were established per marsh in
 <em>J. roemerianus </em>stands to collect insects using a
 variety of replicated survey methods, including pan trapping,
 line-transect netting, and flower collection, as described below (n = 4
 per marsh). Within one randomly selected site per marsh, we also collected
 insects via light trapping (n = 1 per marsh), which sampled insects from a
 larger area than the replicated quadrats used for other sampling
 methods.  <strong><em>Replicated Insect
 Sampling Methods</em></strong> To account
 for pollinators and other flying insect taxa, we established 12 colored
 pan traps in each of the four quadrats per marsh. These pan traps (30 mL;
 5 cm diameter) were placed on platforms positioned at the local average
 inflorescence height of the surrounding <em>J. roemerianus
 </em>stand to ensure that they were at an optimal height for
 attracting pollinators (Montgomery et al., 2021). The platforms were made
 of PVC pipes with open, 36 x 30 x 8 cm plastic storage containers secured
 on top, in which the 12 pan traps were placed (Montgomery et al., 2021).
 Sets of pan traps included four traps of each color that were painted
 either blue, yellow, or white to attract a variety of insect taxa. They
 contained a solution of ~2.5 cm of water mixed with several drops of
 unscented dish soap, which was prepared as described in Montgomery et al.
 (2021). Once per month, we deployed the pan traps in the field for 20 – 24
 hours. Upon collection, insects were preserved in 70% ethanol to later be
 identified and archived in the lab at the University of Alabama according
 to Boyer et al. (2020).  In addition to pan traps, we
 conducted line-transect netting once per month in each of the four
 quadrats at each marsh (n = 4 per marsh). This form of sampling primarily
 targeted flying insect taxa of various functional feeding groups, as well
 as herbivores present on <em>J. roemerianus </em>shoots.
 Within each quadrat, we established one transect (5 m long) running
 parallel to the canal and the tidal creek in the constructed and reference
 marshes, respectively. Around mid-day, we swept each transect for 5
 minutes using a 30-cm ringed, fine-meshed net suitable for retaining
 macroinvertebrates (BIOQUIP Student Insect Net). Upon collection, all
 insects were preserved temporarily in Ziploc bags containing a paper towel
 soaked in 70% ethanol before being transferred to scintillation vials
 filled with 70% ethanol. Upon return to the lab, insects were identified
 and pinned or otherwise preserved (Boyer et al., 2020).
 <strong><em>Light Trap Sampling
 Method</em></strong> To attract
 night-flying insects across all functional feeding groups, we conducted
 light trapping monthly in one, randomly selected quadrat per marsh using
 an ultraviolet light (BIOQUIP’s Night Collecting Light, DC, 12 Volt, 15
 Watt Blacklight). Light traps have been shown to attract flying insects
 from distances as far as 40 m, and they capture many more individuals per
 trap than the other sampling approaches in this study. To maximize the
 effectiveness of each trap and for logistical reasons, we deployed only
 one light trap per marsh (n = 1 per marsh), for a total of three light
 traps overall. Light trapping was conducted in the same quadrat in each
 marsh from month-to-month. This light trap apparatus consisted of a
 platform that supported a white plastic container (36 x 30 x 8 cm) holding
 approximately 2 L of the same soap and water solution used in the pan
 traps (Montgomery et al., 2021). A suspended UV light was positioned above
 each plastic container to attract night-flying insects. Light traps
 remained in the field overnight, and insects were collected the following
 morning. Upon collection, they were transferred into 50-mL conical
 centrifuge tubes (VWR Inc.) containing 70% ethanol for subsequent
 identification, preservation, and storage in the lab. 
 Due to the large number of insects captured by the light traps,
 we used a subsampling method to estimate the composition of insects
 collected using a grid system, similar to that described by Doğramaci et
 al. (2010).Insect samples were poured into a pan (28 x 20 cm; length x
 width) that was evenly divided into 16 cells (7 x 5 cm; length x width).
 All cells were first scanned by eye and then under a stereo microscope for
 rare insects (MOTIC SMZ-140 and Meiji Techno EMZ-8TR). Then, four randomly
 selected cells within each sample were pooled together for identification.
 Lastly, the total number of insects of each identified taxa were
 multiplied by four to estimate the overall abundance of insect taxa within
 the 16-cell pan. In addition to the insect surveying
 methods described above, inflorescences were collected once per month
 during the flowering period of <em>J. roemerianus </em>in
 April, May, and June<em> </em> in each quadrat (n = 4) to
 account for inconspicuous or minute taxa. Near mid-day, the inflorescences
 were clipped and quickly dropped into jars containing 70% ethanol
 (Montgomery et al., 2021). The inflorescences were later analyzed for
 insects using stereo microscopes (MOTIC SMZ-140 and Meiji Techno EMZ-8TR).
 As with all other insects collected, they were archived in the lab after
 identification.  Timed floral counts also were
 conducted monthly in each quadrat per marsh during May, June, and July
 (Boyer et al., 2020; Montgomery et al., 2020). Timed floral counts
 consisted of observing and filming <em>J. roemerianus
 </em>inflorescences within a 0.25 m<sup>2 </sup>area for
 a total of 5 minutes per quadrat during each month, with observed insect
 visitations recorded in a field notebook. Insects captured on film were
 identified to the lowest taxonomic level possible. Identification of
 insect taxa was largely successful, as subsequent film analysis revealed
 that several insect taxa were observed visiting <em>J. roemerianus
 </em>inflorescences during floral surveys, including soldier beetles
 (family <em>Cantharidae</em>) during May and June. Thrips
 belonging to family <em>Phlaeothripidae</em> and suborder
 Terebrantia were also found on inflorescences across the entire sampling
 period. While most insects visiting inflorescences were identified, small
 flying insects could not be visually identified to taxa. Identified taxa
 were included in abundance counts for the months in which surveys were
 performed. <strong><em>Floral Counts and
 Herbivory</em></strong> To quantify the
 density of <em>J. roemerianus</em> inflorescences potentially
 available as a resource to insect pollinators, we counted inflorescences
 in all four quadrats of each marsh in June. Inflorescence counts were
 recorded within each quadrat (n = 4 per marsh) by randomly selecting four
 smaller, sub-quadrats (0.25 m<sup>2</sup>) per quadrat. These
 smaller sub-samples were averaged to determine inflorescence counts for
 each quadrat (n = 4 per marsh). Lastly, herbivore
 damage was quantified by clipping <em>J. roemerianus
 </em>stems at the soil surface within four randomly selected 0.25
 m<sup>2 </sup>sub-plots in each of the quadrats per marsh in
 September. Upon collection, clippings were bagged and brought back to the
 lab for analysis, where they were then photographed and analyzed for
 percent surface area of herbivory damage using ImageJ software. Both
 halves of the cylindrical shoots were photographed and analyzed using
 ImageJ software (https://imagej.nih.gov/ij/, 1997-2018) to determine their
 total area and the area scarred by herbivore grazing. The percent surface
 area of herbivory was quantified by dividing the area affected by
 herbivory by the total area of shoots. By measuring damage in September,
 this approach captured the cumulative extent of herbivory throughout the
 growing season.  <strong><em>Habitat
 Classifications</em></strong> To explore
 the possibility of differences in resource availability across marshes, we
 quantified the relative area of habitats at each marsh by creating a land
 use/land cover (LULC) map using the ESA WorldCover 10m v100 dataset in
 Google Earth Engine. Around each sampled quadrat (n = 4 per marsh), we
 defined a 250 m radius in which to characterize habitat types. Habitats
 included open water, herbaceous wetland, marsh grassland, forest,
 developed area, and barren. All quadrats were combined for each marsh and
 the percent area of each habitat type was determined.
 <strong>Literature cited</strong>
 Boyer, K. J., Fragoso, F. P., Dieterich Mabin, M. E., &
 Brunet, J. (2020). Netting and pan traps fail to identify the pollinator
 guild of an agricultural crop. <em>Scientific Reports</em>,
 <em>10</em>(1), 13819. https://doi.org/10.1038/s41598-020-70518-9 Doğramaci, M., DeBano, S. J., Wooster, D. E., & Kimoto, C. (2010). A method for subsampling terrestrial invertebrate samples in the laboratory: estimating abundance and taxa richness. <em>Journal of Insect Science</em>, <em>10</em>(25), 1–17. https://doi.org/10.1673/031.010.2501 Montgomery, G. A., Belitz, M. W., Guralnick, R. P., & Tingley, M. W. (2021). Standards and best practices for monitoring and benchmarking insects. <em>Frontiers in Ecology and Evolution</em>, <em>8</em>. https://doi.org/10.3389/fevo.2020.579193 Montgomery, I., Caruso, T., & Reid, N. (2020). Hedgerows as ecosystems: Service delivery, management, and restoration. <em>Annual Review of Ecology, Evolution, and Systematics</em>, <em>51</em>(1), 1–6. https://doi.org/10.1146/annurev-ecolsys-012120-100346
description: All data files are usavle in excel.
description: | | | | | | | | |
 ------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------- | ------------------------------------------------- | ------------------------------------------------------------------------------------------------------------- | ------- | ------------------------------------------------------ | | This readme file was generated on 2023-07-05 by Emily Fromenthal | | | | | | | | | | | | | | | | GENERAL INFORMATION | | | | | | | | | | | | | | | | Title of Dataset: Beyond the Marsh: Tidal Marsh Landscape Position Influences Insect Community Structure | | | | | | | | | | | | | | | | Author/Principal Investigator Information | | | | | | | | Name: Emily Fromenthal | | | | | | | | Institution: University of Alabama | | | | | | | | Email:[efromenthal@crimson.ua.edu](mailto:efromenthal@crimson.ua.edu) | | | | | | | | Author/Associate or Co-investigator Information | | | | | | | | Name: Shelby Rinehart | | | | | | | | ORCID:0000-0001-9820-1350 | | | | | | | | Institution: University of Alabama & Drexel University | | | | | | | | Email: [srinehart@ucdavis.edu](mailto:srinehart@ucdavis.edu) OR [sarinehart@ua.edu](mailto:sarinehart@ua.edu) | | | | | | | | Author/Associate or Co-investigator Information | | | | | | | | Name: Jacob M Dybiec | | | | | | | | Institution: University of Alabama | | | | | | | | Email: [jmdybiec@crimson.ua.edu](mailto:jmdybiec@crimson.ua.edu) | | | | | | | | Author/Associate or Co-investigator Information | | | | | | | | Name: Julia A Cherry | | | | | | | | Institution: University of Alabama | | | | | | | | Email: [cherr002@ua.edu](mailto:cherr002@ua.edu) | | | | | | | | | | | | | | | | Date of data collection: 2021-04 through 2021-10 | | | | | | | | | | | | | | | | Geographic location of data collection: West Fowl River | Coden | Alabama | USA | | | | | CON-1: 30.368 N | -88.152 W | | | | | | | CON-2: 30.367 N | -88.151 W | | | | | | | NAT: 30.368 N | -88.160 W | | | | | | | | | | | | | | | Information about funding sources that supported the collection of the data: | | | | | | | | The Society of Wetland Scientists | | | | | | | | University of Alabama | Department of Biological Sciences | | | | | | | | | | | | | | | | | | | | | | | SHARING/ACCESS INFORMATION | | | | | | | | | | | | | | | | Licenses/restrictions placed on the data: None | | | | | | | | | | | | | | | | Links to publications that cite or use the data: Please see the publication associated with these data in XXXXXXXX (doi: XXXXXX) | | | | | | | | | | | | | | | | Recommended citation for this dataset: | | | | | | | | | | | | | | | | Fromenthal | E | S. Rinehart | J.M. Dybiec | and J.A Cherry. Beyond the Marsh: Tidal Marsh Landscape Position Influences Insect Community Structure. Dryad | Dataset | [https://doi.org/XXXXXXXXX](https://doi.org/XXXXXXXXX) | | | | | | | | | | | | | | | | | | DATA & FILE OVERVIEW | | | | | | | | | | | | | | | | File List: | | | | | | | | Taxa- count data for each insect taxon observed at study sites | | | | | | | | Biodiversity- total individuals | taxa richness | and Shannon-Weiner diversity (H') indeces for each quadrat | | | | | | FloralCounts- total count | average count | standard deviation | and variance of Juncus roemerianus inflorescences | | | | | Herbivory- percent area of herbivory damage on J. roemerianus shoots collected from each quadrat in each marsh. | | | | | | | | | | | | | | | | METHODOLOGICAL INFORMATION | | | | | | | | | | | | | | | | Description of methods used for collection/generation of data: See the publication associated with these data in XXXXXXXX (doi: XXXXXX) for details on methods. | | | | | | | | | | | | | | | | Methods for processing the data: See the publication associated with these data in XXXXXXXX (doi: XXXXXX) for details on methods. | | | | | | | | | | | | | | | | Instrument- or software-specific information needed to interpret the data: Microsoft Excel | | | | | | | | | | | | | | | | Environmental/experimental conditions: CON-1 and CON-2 are two constructed tidal marshes hydrologically connected via canal to the West Fowl River in Mobile County | Alabama. NAT is a reference marsh directly connected to the West Fowl River. All marshes are located in a sub-tropical estuary along the northern Gulf fo Mexico. | | | | | | | | | | | | | | | Describe any quality-assurance procedures performed on the data: | | | | | | | | General QA/QC done by all co-authors. | | | | | | | | | | | | | | | | People involved with sample collection | processing | analysis | and/or submission: | | | | | Emily Fromenthal was involved in sample collection | processing | analysis | and submission. | | | | | Shelby Rinehart was involved in sample collection | analysis | and submission. | | | | | | Jacob M Dybiec was involved in sample collection and analysis. | | | | | | | | Julia A Cherry was involved in analysis and submission. | | | | | | | | | | | | | | | | DATA-SPECIFIC INFORMATION FOR: Taxa | | | | | | | | Number of variables: 86 | | | | | | | | Number of cases/rows: 146 | | | | | | | | Missing data codes: No data missing. | | | | | | | | Specialized formats or other abbreviations used: N/A. | | | | | | | | | | | | | | | | Variable List: | | | | | | | | Marsh-indicates the marsh (CON1 | CON2 | or NAT) that data was collected from | | | | | | Month- month that data was collected | | | | | | | | Method- method used to collect data (Pan | Net | Light | FC) | | | | | Quadrat- indicates the replicate quadrat (i.e. | CON1-1 | CON1-2 | etc.) that data was collected from | | | | | Variables E-CH (5-86) represent counts of indiviual taxa identified to the lowest possible taxa (family | in most cases). | | | | | | | | | | | | | | | DATA-SPECIFIC INFORMATION FOR: Biodiversity | | | | | | | | Number of variables: 5 | | | | | | | | Number of cases/rows: 12 | | | | | | | | | | | | | | | | Missing data codes: No missing data. | | | | | | | | Specialized formats or other abbreviations used: | | | | | | | | H'- Shannon-Wiener diversity index; calculated using the formula H^'= -\_(i=1)^Rp\_i ln p\_i | | | | | | | | | | | | | | | | Variable List: | | | | | | | | Marsh- indicates the marsh (CON1 | CON2 | or NAT) that data was collected from | | | | | | Quadrat- indicates the replicate quadrat (i.e. | CON1-1 | CON1-2 | etc.) that data was collected from | | | | | Total Individuals- total count of individual insects per quadrat across all sampling strategies. | | | | | | | | Taxa Richness- number of unique taxa identified per quadrat across all sampling stratagies. | | | | | | | | H'- Shannon-Wiener diversity calculated for each quadrat across all sampling stratagies. | | | | | | | | | | | | | | | | DATA-SPECIFIC INFORMATION FOR: FloralCounts | | | | | | | | Number of variables: 4 | | | | | | | | Number of cases/rows: 37 | | | | | | | | | | | | | | | | Missing data codes: No missing data. | | | | | | | | Specialized formats or other abbreviations used: None | | | | | | | | | | | | | | | | Variable List: | | | | | | | | Marsh- indicates the marsh (CON1 | CON2 | or NAT) that data was collected from | | | | | | Quadrat- indicates the replicate quadrat (i.e. | CON1-1 | CON1-2 | etc.) that data was collected from | | | | | Replicate- inducates which sub-sample from each quadrat is associated with each observation | | | | | | | | Floral count- the number of flowering J. roemerianus shoots in each observation. | | | | | | | | | | | | | | | | DATA-SPECIFIC INFORMATION FOR: Herbivory | | | | | | | | Number of variables: 7 | | | | | | | | Number of cases/rows: 12 | | | | | | | | | | | | | | | | Missing data codes: No missing data. | | | | | | | | Specialized formats or other abbreviations used: N/A | | | | | | | | | | | | | | | | Variable List: | | | | | | | | Quadrat- indicates the replicate quadrat (i.e. | CON1-1 | CON1-2 | etc.) that data was collected from. | | | | | Marsh- notes which tidal wetland site the sample was collected from. | | | | | | | | Herbivory (sq inch)- area of insect herbivory damage/scars in square inches | | | | | | | | Herbivory (cm2)- area of insect herbivory damage/scars per cm2 | | | | | | | | Total area (sq inch)- total size (area) of J. roemerianus shoots in square inches | | | | | | | | Total area (cm2)- total size (area) of of J. roemerianus shoots in cm2. | | | | | | | | % Herbivory- the percent area of J. roemerianus shoots with insect herbivory damage | | | | | | |