Data from: Fish modulate how connectivity and local factors shape food webs of permanent ponds
Data files
Dec 25, 2024 version files 11.79 KB
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data_ms.csv
5.44 KB
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README.md
6.35 KB
Abstract
The propagation of metacommunity processes through local trophic interactions has seldom been explored, particularly in empirical studies. This study examines how local environmental conditions and metacommunity connectivity influence community assembly and food web structure in pondscapes. We survey taxonomic richness, abundance, and isotopic niches across multiple assemblage, including zooplankton, macroinvertebrates, tadpoles, turtles, and fish. A gradient in the composition of the pond community representing the dominance of fish or other taxa and another gradient associated with macroinvertebrate diversity were evidenced. Pond size and connectivity promoted fish richness and abundance, representing the main path through which metacommunity processes cascade down within communities, determining the assembly of the whole system. The dominance of fish was associated with large food chains, a reduction in the width of the food web width, and the trophic spacing. Local conditions such as macrophyte coverage and pond size modulate the strength of these fish effects, determining the representation of macroinvertebrates and amphibians. Consequently, the effects of pond connectivity on community assembly may result as a consequence of isolation's influence on top predators' performance, rather than by the direct effect of dispersal on different species, as is usually assumed. Metacommunity theory has highlighted the direct effect of dispersal on species performance and diversity. Our study highlights the indirect influence of landscape mediated by keystone species, which connect metacommunity dispersal with local community processes more than previously thought.
README: Fish modulate how connectivity and local factors shape food webs of permanent ponds
https://doi.org/10.5061/dryad.j6q573nqr
Description of the data and file structure
The data was collected as part of a study investigating how local environmental conditions and metacommunity connectivity influence community assembly and food web structure in pondscapes. The research focused on assessing taxonomic richness, abundance, and isotopic niches across various assemblages, including zooplankton, macroinvertebrates, tadpoles, turtles, and fish. Sampling was conducted in multiple ponds across two pondscapes in Uruguay. The dataset includes local environmental variables of the ponds, such as area, maximum depth, macrophyte coverage, and edge heterogeneity, as well as centrality measures. Additionally, the dataset includes community-level variables such as abundance and richness of different assemblages, along with isotopic niche metrics.
Files and variables
File: data_ms.csv
Description:
Variables
- pond_id: Unique identifier for each pond in the study.
- region: Geographical region of the pond, represented by categories such as "Paysandú" or "Aceguá."
- weighted_degree_centrality_std: Standardized measure of weighted centrality in the connectivity network of ponds, used to facilitate comparisons between ponds.
- area_ellipse: Area of the pond estimated using an ellipse fitted to the shape of the pond, in square meters (m²).
- max_depth: Maximum depth of the pond, measured in meters.
- ph: pH level of the water in the pond.
- temperature: Water temperature in the pond, measured in degrees Celsius.
- conductivity: Electrical conductivity of the water in the pond, in microsiemens per centimeter (μS/cm).
- o_dis_porc: Percentage of dissolved oxygen in the water.
- o_dis_mg: Concentration of dissolved oxygen in the water, measured in milligrams per liter (mg/L).
- tds: Total dissolved solids in the water, measured in parts per million (ppm).
- salinity: Salinity of the water, measured in concentration units of salt.
- turbidity: Water turbidity, measured in nephelometric turbidity units (NTU).
- macrophyte_cover: Cover of macrophytes (aquatic plants) in the pond, expressed as the percentage of area covered by these plants.
- edge_heterogeneity: Heterogeneity of the pond's edge, reflecting the diversity of features along the pond's borders, such as the presence of different types of vegetation or structures.
- fishes_seac: Standard Ellipse Area with Sample Size Correction (SEAC) for fish, representing the ecological niche occupied by fish species, adjusted for sample size. This metric reflects the isotopic niche space for fish within the pond.
- macroinvertebrates_seac: Standard Ellipse Area with Sample Size Correction (SEAC) for macroinvertebrates, representing the ecological niche occupied by macroinvertebrate species, adjusted for sample size. This metric reflects the isotopic niche space for macroinvertebrates within the pond.
- tadpoles_seac: Standard Ellipse Area with Sample Size Correction (SEAC) for tadpoles, representing the ecological niche occupied by tadpole species, adjusted for sample size. This metric reflects the isotopic niche space for tadpoles within the pond.
- SEAc: Total Standard Ellipse Area with Sample Size Correction (SEAC) for all groups combined, representing the overall ecological niche space occupied by the different trophic groups in the pond, adjusted for sample size.
- N_range: Nitrogen isotopic range, indicating the variability in nitrogen isotopic values among the organisms in each pond.
- C_range: Carbon isotopic range, indicating the variability in carbon isotopic values among the organisms in each pond.
- TA: Trophic width, a measure of the food chain's breadth in a pond, determined by the trophic separation between different organisms.
- CD: Centroid distance, mean Euclidean distance of each species from the food web centroid, reflecting the average trophic diversity and spacing between species
- NND: Nearest Neighbor Distance, represents the mean euclidean distance of each species to the nearest neighbour species within the biplot and indicates the trophic spacing of species.
- SDNND: Standard deviation of Nearest Neighbor Distance, describes the evenness of this packing, where lower values indicate a uniform distribution of trophic niches for each species in a food web
- offset_seine_fish: Sampling effort with the seine fish net, measured in meters of net haul. This variable represents the amount of effort applied to capture macroinvertebrates, tadpoles and fishes in the study ponds.
- offset_zoo: Sampling effort for zooplankton, measured as the volume of water filtered during sampling. This variable represents the amount of effort applied to collect zooplankton in the study ponds.
- n_tadpoles: Tadpole abundance in the pond, expressed as the total number of tadpole individuals.
- n_fishes: Fish abundance in the pond, expressed as the total number of fish individuals.
- n_macroinvertebrates: Macroinvertebrate abundance in the pond, expressed as the total number of macroinvertebrate individuals.
- n_zooplankton: Zooplankton abundance in the pond, expressed as the total number of zooplankton individuals.
- s_tadpoles: Tadpole species richness in the pond, measured as the number of different tadpole species present.
- s_macroinvertebrates: Macroinvertebrate species richness in the pond, measured as the number of different macroinvertebrate species present.
- s_fishes: Fish species richness in the pond, measured as the number of different fish species present.
- s_total: Total species richness in the pond, including the combined richness of tadpoles, macroinvertebrates and fishes species.
Missing data: NA
Code/software
The data analysis was performed using common R packages and functions, as detailed in the methodology of the paper. The analysis included Principal Component Analysis (PCA), Principal Coordinate Analysis (PCoA), and model selection procedures, all of which are standard approaches in ecological research. These models are implemented with widely used packages like lme4
for statistical modeling. For further details on the analysis, please refer to the article's methodology section.
Methods
The data were collected in two pondscapes located in the grassland landscape of Uruguay, where sampling was conducted in permanent ponds to assess taxonomic richness, abundance, and isotopic niches of different assemblages, including zooplankton, macroinvertebrates, tadpoles, turtles, and fish. The sampling was designed to explore how local conditions and metacommunity connectivity influence community structure and food web dynamics, as described in the forthcoming article titled 'Fish modulate how connectivity and local factors shape food webs of permanent ponds' (to be published in Oikos). Following data collection, the data were processed using statistical analyses in R, including data cleaning and correction for sampling effort, as well as analyses to evaluate trophic interactions and the effects of connectivity and local conditions on community composition and food web structure.