I. Data Set Descriptors
II. Research Origin Descriptors
III. Data Set Status and Accessibility
IV. Data Set Structural Descriptors
CLASS I. DATA SET DESCRIPTORS
A. Data Set Title: Food webs including parasites, biomass, body sizes, and life stages, for three California/Baja California estuaries.
B. Data Set Identification Code: HechEtAl2010-3fwebs.
C. Data Updates: The data set may be periodically updated. For a record of previous versions and identification codes see Table 1.
E. Abstract: This data set presents food webs for three North American Pacific Coast estuaries and a “Metaweb” composed of the species/stages compiled from all three estuaries. The webs have four noteworthy attributes: (1) parasites (infectious agents), (2) body-size information, (3) biomass information, and (4) ontogenetic stages of many animals with complex life cycles. The estuaries are Carpinteria Salt Marsh, California (CSM); Estero de Punta Banda, Baja California (EPB); and Bahia Falsa in Bahia San Quintín, Baja California (BSQ). Most data on species assemblages and parasitism were gathered via consistent sampling that acquired body size and biomass information for plants and animals larger than ~1 mm, and for many infectious agents (mostly metazoan parasites, but also some microbes). We augmented this with information from additional published sources and by sampling unrepresented groups (e.g., plankton). We estimated free-living consumer–resource links primarily by extending a previously published version of the CSM web (which the current CSM web supplants) and determined most parasite consumer–resource links from direct observation. We recognize 21 possible link types including four general interactions: predators consuming prey, parasites consuming hosts, predators consuming parasites, and parasites consuming parasites. While generally resolved to the species level, we report stage-specific nodes for many complex-life-cycle animals. We include additional biological information for each node, such as taxonomy, lifestyle (free-living, infectious, commensal, mutualist), mobility, and residency. The Metaweb includes 500 nodes, 314 species, and 11,270 links projected to be present given appropriate species’ co-occurrences. Of these, 9247 links were present in one or more of the estuarine webs. The remaining 2023 links were not present in the estuaries but are included here because they may occur in other places or times. Initial analyses have examined and are examining the interrelationships between consumer strategy, body size, abundance, biomass, trophic level, life stages, and food-web structure and dynamics. Further use of these data may enable a more general exploration how infectious processes and parasites impact communities and ecosystems. Additionally, we present the data and metadata in a standardized format, attempting to provide a system-neutral template for future food-web assembly and publication.
F. Key Words:Bahia San Quintín (Mexico); biomass; body size; Carpinteria Salt Marsh, California (USA); complex life cycles; consumer resource; Estero de Punta Banda (Mexico); estuary; food webs; infectious agents; parasites; trophic interactions.
CLASS II. RESEARCH ORIGIN DESCRIPTORS
A. Overall Project Description: This data paper is part of our general and on-going efforts to understand the role of parasites (infectious agents) in ecosystems and to examine how parasites compare to free-living species in basic ecological and evolutionary attributes.
B. Research Motivation: Food webs encapsulate several aspects of natural communities by simultaneously capturing species diversity and consumer-resource interactions (Cohen 1978, Pimm 1982, Polis and Winemiller 1996, Pascual and Dunne 2006). Ironically, the most diverse consumers, parasites, have not been included in most food webs. Recent efforts to include parasites in food webs (e.g., Huxham and Raffaelli 1995, Thompson et al. 2005, Lafferty et al. 2006b, Hernandez and Sukhdeo 2008, Amundsen et al. 2009) demonstrate that parasites can alter food-web topology and robustness (above references and Lafferty et al. 2006a, Lafferty et al. 2008, Lafferty and Kuris 2009). On another front, food-web science has also recently advanced by including species' body sizes, biomasses, and abundances (e.g., Cohen et al. 2003, Woodward et al. 2005a, Brose et al. 2006, Berlow et al. 2009, Cohen et al. 2009). Related to this, we recently documented that parasites contribute substantial biomass to three estuaries in California and Baja California, suggesting the energetic importance of parasites to food web function (Kuris et al. 2008). We had previously constructed a topological web including parasites for one of these estuaries (Lafferty et al. 2006b). We decided to extend our previous efforts by constructing comprehensive food webs, for these three estuaries, that include body size and biomass information for both free-living and parasitic species.
Additionally, we hope to facilitate the assembly and publication of other food webs. To this end, we have presented the data in a manner that may serve as a template for future webs. The data include node and link information that extends far beyond a simple binary indication of presence or absence, including much of the information Cohen et al. (1993) identified as being important to improve food web data sets, in addition to other sorts of information that we have identified as being useful. Comprehensive metadata defines all data columns and variables. To increase utility for researchers working in other systems, these columns and variables are sufficiently general to be broadly applicable. Additionally, we describe further attributes to possibly include in future work. Finally, we have striven to present the data and metadata in a way that is user- and viewer-friendly, but which is also compatible with the latest ecological metadata language and data catalogues (e.g., 'MetaMorph')(Fegraus et al. 2005).
We hope these data facilitate continued study of the role of parasites (infectious agents) in food webs, and further exploration of how parasites compare to free-living species. We encourage researchers to examine and use these food webs and to contact us concerning questions, improvements, and analyses of these data.
C. General Methodology
C.1. System Definition
C.1.i. Description: We constructed webs for three estuaries that were the subject of previous intensive empirical work quantifying the ecosystem-level biomass of free-living and parasitic species (Kuris et al. 2008). The three estuaries are in California and Baja California: Carpinteria Salt Marsh (CSM), Estero de Punta Banda (EPB), and Bahia Falsa in Bahia San Quintín (BSQ). The total areas were 61 ha for CSM, 707 ha for EPB, and 144 ha for BSQ (these areas exclude subtidal lagoon portions of BSQ and EPB). For more information on the research, see particularly Kuris et al. (2008), but also Torchin et al. (2005) and Whitney et al. (2007). In the above research, we quantified only organisms encountered in the intertidal zone of each estuary (including birds, fishes, and plankton). As described below, we augmented the data from the above research with information from additional published sources and by sampling unrepresented groups (e.g., plankton). For additional background information for each estuary please visit the following websites: (CSM) http://carpinteria.ucnrs.org, (EPB) http://proesteros.cicese.mx/investigacion/inv_hum/PuntaBanda/index.htm, and (BSQ) http://proesteros.cicese.mx/investigacion/inv_hum/SanQuintin/index.htm.
C.1.ii. Spatio-temporal Coverage:
|Geographic Description: Carpinteria Salt Marsh (CSM)|
|Bounding Coordinates||East: -119.53|
|Temporal Coverage||Beginning Date: 2003|
|Ending Date: 2008|
|Geographic Description: Estero de Punta Banda (EPB)|
|Bounding Coordinates||East: 116.60|
|Temporal Coverage||Beginning Date: 1992|
|Ending Date: 2005|
|Geographic Description: Bahia Falsa in Bahia San Quintín (BSQ)|
|Bounding Coordinates||East: 116.02|
|Temporal Coverage||Beginning Date: 1994|
|Ending Date: 2005|
C.2.i. Orientation: Nodes for the three estuary food webs and the Metaweb are listed in the Nodes data files. Two metadata tables describe the Nodes data files. Table 2A defines node data column headers. Table 2B defines node data column variables. Below, we provide additional background information on the nodes.
C.2.ii. Node Inclusion: For nodes, we sought primarily to include species and/or stages for which we had biomass and/or body size information. The bulk of the nodes in the three webs were encountered in the ecosystem-level quantification described in Kuris et al. (2008), which estimated biomass and body size. We also include species that we know to be present, but that were not adequately sampled by the sampling techniques described in Kuris et al. (2008). Some of these species (e.g., the elasmobranchs) were sampled by other surveys of the estuaries, allowing estimation of biomass. Because we wish this web to supplant the original CSM web (Lafferty et al. 2006b), we also included all species from the original CSM web in the current CSM web (and EPB and BSQ if appropriate), including a few for which we could obtain no biomass or body size information.
Because the nodes in these webs are resolved to include ontogenetic life stages, in some cases we added stages that must be present in the webs, but for which we had no direct quantification. We generally did this for species with undetected life stages for which we could provide an indirect quantification of biomass. For example, to the EPB food web, we added the presence and estimated biomass of the undetected snail Acteocina inculta because it is an obligate intermediate host for a parasite that we detected as adults. Information on these decisions is in the "Biomass Notes" data column. As another example, because we quantified the free-swimming stages (cercariae) for many trematodes, to increase consistency within taxonomic group, we also added presence of the unquantified free-swimming stages of some species for which we had detected only the immediately succeeding metacercarial cyst stages.
We sometimes connected stages (as being the same species) that we had quantified, but for which we had no concrete information that they belong to the same species. For example, we matched the adult hemiurid trematode in fishes, Hysterolecitha trilocalis, with the hemiurid parthenitae and cercariae in the snail Acteocina inculta. As another example, we matched adult and/or juvenile polychaetes to portions of the aggregated biomass of polychaete trochophore and nectochaete larvae. Taking such steps should result in food webs that more closely approximate reality than leaving blatantly unreal gaps in life cycles and artificially inflating species richness. We will update the food web when we acquire substantial new information.
C.2.iii. Node Resolution: The "Node Resolution" column in the node data files indicates the degree of resolution for each node. Most of the nodes are species, or species-specific life stages. Study design constraints led us to classify some individuals to "morphospecies". We often did this for rarer and small organisms. We also employed morphospecies classification for some more common animals, particularly members of certain groups, e.g., amphipods and polychaetes. Thus, although such nodes are not identified below some higher taxonomic category, they generally do represent distinct species. Each node is unique, as indicated by its unique number code and working name.
In addition to providing a unique working name for each node, and indicating the general organismal "Group" to which each node belongs, the data sets also include a series of columns for the taxonomic hierarchy (i.e., Kingdom through Specific epithet). This is primarily to aid users in understanding node identity and to facilitate taxonomic diversity analyses, vs. representing the adoption of any particular taxonomic scheme.
C.2.iv. Additional Node Classifications: To facilitate analyses and interpretation, we have additionally classified nodes by several different schemes. The node metadata tables list and define all such categories and variables (Tables 2A, 2B). For example, we indicate each node's "Feeding type" (feeding, non-feeding, autotrophic), "Lifestyle" (e.g., free-living, infectious, commensal), "Consumer Strategy" (e.g., predator, macroparasite, pathogen, detritivore), and "Native" or non-native status. Additionally, the columns "Mobility" and "Residency" indicate for each node the general degree of vagility characterizing individuals on daily and seasonal time scales. One reason why Mobility and Residency may be useful to consider is because they impact the expected proportion of a node's links that the web captures. For example, it may be important to recognize that a migrant can have low linkage completeness because a substantial number of an individual's interactions occur outside of the system.
C.2.v. Node Biomass and Abundance Estimation: The biomass estimates largely came from the quantification described in Kuris et al. (2008). Biomass refers to wet weight (or "fresh weight"), including hard parts, such as shells. Although abundance (numerical density) is obtainable and well-approximated by dividing biomass by body size, we also include direct estimates of abundance (numerical density) for most of the consumers sampled in Kuris et al. (2008), which represent the 460 nodes used in Hechinger et al's (unpublished) analysis of abundance versus body-size scaling. For those species not included in Kuris et al. (2008), we estimated biomass in several ways. This ranged from using information from other surveys, to extrapolation from relationships quantified in one of the other food webs. Additionally, in some cases, we acquired or had access to aggregated assemblage-level biomass estimates. In these situations, to take advantage of these data and to better approximate reality, we assigned portions of the aggregate biomass to species, usually following the relative abundances of the species at other stages. For example, we had plankton survey data that provided a snapshot of the aggregate bivalve larval biomass (trochophores, veligers) in CSM that we partitioned to species following the relative abundances of adult bivalve species quantified in benthic sampling. To facilitate transparency concerning the origin of biomass estimates, the 'node' data tables indicate the particular biomass estimation method used for each node, and metadata Table 2B lists and defines each method.
C.2.vi. Node Body Size Estimation: Similar to the biomass estimation, we estimated mean body size in several ways, largely as described in Kuris et al. (2008). Body size represents individual body mass (fresh weight, including hard parts) characterizing a species or stage in the local population. The estimates range from direct size measurements of randomly encountered individuals in each estuary, to drawing upon information in the literature, or approximating the size of the species to that of other species. To facilitate clarity concerning the origin of body size estimates, the 'node' data tables indicates the particular body size estimation technique used for each node, and metadata Table 2B lists and describes more thoroughly each method.
C.3.i. Link Orientation: Consumer-resource links for the three estuary food webs and the Metaweb are listed in the links data files. Two metadata tables describe the links data files. Table 3A defines all column headers. Table 3B defines all column variables, except for the Link Types, which are indicated in Table 3C. Below, we provide additional background information.
C.3.ii. Link Determination: We first constructed a Metaweb for the nodes compiled from all three estuaries (similar to Havens' (1992) methodology). To assign links, we started with the published nodes and links from the original CSM web. We assumed those links occurred in the other estuaries if the appropriate nodes co-occurred. We then generated links for nodes not present in the original CSM web. We did this in several ways. For the bulk of free-living nodes, we started by assuming that similar species consume and are consumed by the same things. To do this, we assigned, to each new node, model nodes from the original CSM web: a model node for consumer links (e.g., amphipod A was assumed to share predators with amphipod B) and a model for resource links (e.g., clam A was assumed to eat the same prey as the similar clam B). We then modified some of these modeled links based on information from the literature, our own observations, or other expert opinion. As in Lafferty et al. (2006b), most parasitic consumer links were based on our direct observations. Exceptions occurred when we logically inferred the presence of undetected or unquantified stages of parasites that were quantified at other life stages (e.g., many adult helminths are designated as consumers of a bird species when the bird preys on an intermediate host containing detected parasite stages infectious to birds). To facilitate transparency concerning how links were assembled, the 'links' data sets include columns ('Evidence' and 'Evidence notes') that indicate the general evidence or rationale for each link. See metadata Table 3B for explicit definitions.
A benefit of inferring links using model consumers and resources was our ability to add 2,023 hypothetical links to the Metaweb, which itself was comprised of 11,270 total links involving the combined species lists of all three estuaries. For instance, leopard sharks did not co-occur with cheekspot gobies in our sampling. But, because cheekspot gobies are similar to other fishes that leopard sharks prey upon at CSM, we modeled that leopard sharks would eat cheekspot gobies given the opportunity. Including such links in the Metaweb may aid the assembly of other empirical or theoretical webs where these species do co-occur.
C.3.iii. Link Type: We provide information on the nature of the individual consumer-resource interactions based on the consumer-resource node classifications and other information. We recognized 21 "Link types" encompassing a wide range of free-living and symbiotic consumer interactions. Given the importance of link types, we have pulled this information from the metadata link variable table and placed it in Table 3C, which provides definitions of all link types. Understanding link types is essential prior to conducting analyses of the network. For instance, links defined as Predation involve predators as consumers, whereas links defined as Parasitic Castration involve parasitic castrators as consumers. Also, several of the link types that are not typically included in food webs do not represent resource dependencies (i.e., Concurrent Predation on Symbionts, Trophic Transmission). For this reason, such links should be excluded from some analyses. However, Concurrent Predation on Symbionts represents mortality sources for symbionts, and Trophic Transmission is important to understand parasite transmission.
D. Data Limitations and Potential Enhancements
D.1. General Note: Although these webs are well resolved, there is uncertainty in link assignment and in the resolution of some nodes. We welcome any input from colleagues allowing improvement of these webs, and will periodically update these datasets if we acquire substantial new data (please check for the latest update before using). In addition to explicitly outlining data limitations, we also outline a few prospects for more general improvement and expansion of food webs.
D.2. Nodes: Perhaps the clearest limitation to these data sets is the under-representation and non-representation of some groups. Ectoparasites of birds and fishes are under-represented. So too, are the 'terrestrial' arthropods (insects, arachnids), particularly the herbivorous insects (many of which are parasites or micropredators on the marsh plants) and their predators and parasites. Also underrepresented are meiofauna, which include the smallest free-living metazoans (e.g., nematodes, gnathostomulidans, and kinorhynchs). Free-living and symbiotic single-celled organisms are also under-represented. Detritus is an important food source that is included as a node but was not quantified in terms of biomass.
Although most nodes represent species (or stages of species), another limitation is that some nodes, such as the benthic diatom assemblage, represent aggregated species. However, members of this diverse guild (e.g., Zedler 1980) are all primary producers (i.e., lack feeding links) and will likely share most links to consumers. The free-living copepod fauna is aggregated into three nodes that represent potentially several species. Further, their parasites are poorly known. However, because many of the parasite species that we sampled almost certainly use copepods as intermediate hosts for other life stages, we inferred that obligate parasite life stages must parasitize copepods. When there was lack of information on specificity, we assumed parasitism of all three copepod nodes. Users of this data set should be aware of this when drawing conclusions where this may be important.
Table 4 lists missing and underrepresented groups and severely aggregated nodes.
D.3. Links: Many (2,480) links in the estuaries were "modeled", being extrapolated from general diet preferences and similarity to other consumers or resources. For instance, a bird coded as eating a small goby species in the original CSM web was assumed to eat similar gobies in the other estuaries. This modeling approach should improve the web because limited direct observation captures only a fraction of actual diet items (Polis 1991, Woodward et al. 2005b). Limiting webs to observed links ensures missing consumer-resource interactions, particularly in a speciose ecosystem where observations are necessarily limited. However, while modeling should improve the quality of the network overall, it will not capture all unobserved links and some modeled links will not actually occur. As noted above, the links data sets clearly indicate which links were modeled, and we will periodically update modeled links as observations become available.
D.4. Body size and Biomass: The estimates of body size and biomass are also approximations of varying quality. For web-wide analyses, any error in body size is dwarfed by the wide range in body size among species of >13 orders of magnitude. The estimates for biomass also have sampling error in addition to probable high natural variation. However, the over 13 orders of magnitude variation between the biomasses of species should serve to diminish the importance of error in the approximation for any node for several types of analyses.
D.5. Potential Enhancements: One possible enhancement for future webs would be to include additional information on links and nodes. For instance, related to our nominal "Link Evidence", an ordinal classification of link or node certainty could reflect the degree of confidence that a particular link or node occurs in a system. This could range from "Certain" to "Tenuous", and would allow both the inclusion of uncertain links in the data set, but also the rapid highlighting of uncertain links for further study or exclusion in analyses. Node certainty is particularly useful when augmenting published food webs using information from the literature, expert opinion or unconventional sources (see McLaughlin et al., in preparation).
Additionally, a "Linkage Completeness" could be used to reflect whether information is lacking for some substantial portion of a node's trophic interactions based either on systematic sampling bias (e.g., not sampling ectoparasites on birds), or given that a particular node spends a substantial time feeding or being fed upon outside of the system.
In addition to improving those aspects of the data indicated above, there are other possible, substantial enhancements to be made to the ecological information contained in future food webs. For instance, the particular "Habitat Affiliation" of a node could be indicated (e.g., infaunal, planktonic, etc.). Also, for observed links, "Link Frequency" and "Link N" provide information on the number of times links were observed and the sampling effort for those observations (e.g., the number of consumer guts examined for a particular prey item). "Diet Fraction" indicates the relative contribution of a link to the diet of a consumer. "Consumption Rate" indicate interaction rates in terms of numbers, biomass, or energy. "Vector From" and "Prey From" are ways to indicate parasite life cycles. For instance, for a malaria organism feeding on a vertebrate, Vector From would be the node for the mosquito vector. For a tapeworm feeding on a vertebrate, Prey From would be the node from which the tapeworm was trophically transmitted. The nodes and links metadata tables include explicit definitions for these column headers and variables to possibly be used in future enhancements or other data sets.
A substantial enhancement would be to indicate non-substitutable resource use. Some individual consumers require separate, non-substitutable resources. For instance, a hummingbird can eat a wide variety of insects and flower nectar, but it needs both nectar and insects. For this reason, it may be useful to split species into non-substitutable resource-use categories, similar to the way we have split some species by life stages (which often require different and non-substitutable resources). To distinguish this coding from life-stage coding, one possibility would be to use the tenths place for life stages (as we have done) and the hundredths place for non-substitutable resource classes within a life stage. For example, a hummingbird is a nectar feeder (stage code X.11) and an insectivore (stage X.12). Such coding would help identify the extent that consumers are sensitive to resource loss.
A final, potential enhancement pertains to the fact that food webs are only subsets of ecological networks. Although generally not included here, ecological networks can include a variety of non-trophic interactions. For instance, species may compete for space, plants require sunlight, etc. Such resources could be designated as resource nodes (as opposed to species nodes) and non-trophic links could be included in a master links file, with an additional column to distinguish trophic and non-trophic link types. Or, non-feeding interactions could be incorporated in separate link tables.
CLASS III. DATA SET STATUS AND ACCESSIBILITY
A. Latest Data Update: The data set may be periodically updated. For a record of previous versions and identification codes see Table 1.
B. Latest Metadata Update: There have been no alterations to the metadata subsequent to first publication.
C. Copyright or Proprietary Restrictions: These data sets are freely available for non-commercial scientific use, given the appropriate scholarly citation.
CLASS IV. DATA SET STRUCTURAL DESCRIPTORS
A. Data Files: Below are the files containing the raw data. The data are in eight discrete, tab-delimited value, end of line <CR>+<LF>, files arranged as four data sets: (1) a 'Metaweb' comprised of the compiled species/stages from all three estuaries, from which all estuary-specific webs can be extrapolated; (2) a food web for Carpinteria Salt Marsh, (3) a food web for Estero de Punta Banda, and (4) a food web for Bahia San Quintín. Each data set has two files: one file containing node-specific information and one file containing link-specific information. Node, species and life cycle stage ID codes are consistent across all tables. For example, Species 1 in the Metaweb Nodes is the same as Species 1 in the CSM_Nodes and Species 1 in the EPB_Links data.
We reiterate that the Metaweb contains the individual estuary webs as well as links not found in any of the three estuaries (see above). Thus, simply amalgamating the three individual estuaries will not recreate the Metaweb. However, the individual estuary webs are easily extractable from the Metaweb because we clearly indicate whether nodes or links occur in any particular estuary. Complete descriptions of the data (both column headers and variables) are in the Metadata Tables section below. To download the entire data set click here, or download individual files click on the relevant heading below.
Metaweb_Nodes.txt – The node information for the compiled Metaweb. File includes 919 rows (not including the header row) and 46 columns, formatted as tab-delimited values with end of lines indicated by <CR>+<LF>. No compression scheme was used. Blank cells indicate that information has not been collected or is not applicable.
Metaweb_Links.txt – The trophic link information for the compiled Metaweb. File includes 11,270 rows (not including the header row) and 20 columns, formatted as tab-delimited values with end of lines indicated by <CR>+<LF>. No compression scheme was used. Blank cells indicate that the information has not been collected or is not applicable.
CSMweb_Nodes.txt – The node information for the Carpinteria Salt Marsh system only. File includes 273 rows (not including the header row) and 46 columns, formatted as tab-delimited values with end of lines indicated by <CR>+<LF>. No compression scheme was used. Blank cells indicate that the information has not been collected or is not applicable.
CSMweb_Links.txt – The trophic link information for the Carpinteria Salt Marsh system only. File includes 3,971 rows (not including the header row) and 20 columns, formatted as tab-delimited values with end of lines indicated by <CR>+<LF>. No compression scheme was used. Blank cells indicate that the information has not been collected or is not applicable.
EPBweb_Nodes.txt - The node information for the Estero de Punta Banda system only. File includes 356 rows (not including the header row) and 46 columns, formatted as tab-delimited values with end of lines indicated by <CR>+<LF>. No compression scheme was used. Blank cells indicate that the information has not been collected or is not applicable.
EPBweb_Links.txt - The trophic link information for the Estero de Punta Banda system only. File includes 5,998 rows (not including the header row) and 20 columns, formatted as tab-delimited values with end of lines indicated by <CR>+<LF>. No compression scheme was used. Blank cells indicate that the information has not been collected or is not applicable.
BSQweb_Nodes.txt - The node information for the Bahia Falsa in the Bahia San Quintín system only. File includes 290 rows (not including the header row) and 46 columns, formatted as tab-delimited values with end of lines indicated by <CR>+<LF>. No compression scheme was used. Blank cells indicate that the information has not been collected or is not applicable.
BSQweb_Links.txt - The trophic link information for the Bahia Falsa in the Bahia San Quintín system only. File includes 3,997 rows (not including the header row) and 20 columns, formatted as tab-delimited values with end of lines indicated by <CR>+<LF>. No compression scheme was used. Blank cells indicate that the information has not been collected or is not applicable.
All_Data_Files.zip - A zip file containing all the above data files.
B. Metadata Tables
Below are the metadata tables, which describe the column header and variable information contained in the above data files. These are the same set of tables linked to in the methods section.
There are four metadata tables (click here to download all four tables) organized into two groups: Tables 2AB refer to the Node data sheets, while Tables 3AC refer to the Links data sheets. There are two types of tables: the A tables describe the general information contained within each column and the B tables define the variables found in each column.
We have aimed to provide a template for the assembly and publication of food webs that is broadly applicable and system neutral. For this reason, we have included columns for which we have no data, but may be useful in the future or for other researchers. Also, we present and define variables that do not occur in our data set.
Table 2A - Column header descriptions for Nodes data files. Column headers are taken directly from the Metaweb_Nodes.txt data file and are followed directly by their descriptions.
Table 2B - Column variable descriptions for Nodes data files. Definitions of variables are organized by the nodes column headers from Table 2A.
Table 3A - Column header descriptions for Links data files. Column headers are taken directly from the Metaweb_Links.txt data files and are followed directly by their descriptions.
Table 3B - Column variable descriptions for Links data files. Definitions of variables are organized by the links column headers from Table 3A. Link-type variables are defined in Table 3C.
Table 3C - Link-type definitions for Links data files. Definitions of Link-type variables are organized for this column header from Table 3A.
Table 4 - Missing and underrepresented groups and severely aggregated nodes.
All_Metadata_Tables.zip – A zipped file containing Tables 2A, 2B, 3A, 3B, 3C, and 4.
We thank Jennifer Dunne, Jim Regetz, and two anonymous reviewers for their helpful discussions and comments on the manuscript.
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