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The objective of the SAGE workshop was to discuss and come to agreement on sampling protocols for terrestrial arthropods in graminoid ecosystems. Minor differences in sampling strategies have resulted in apparently similar protocols producing vastly different data sets. The intent of protocol standardization is to reduce sampling error resulting from differences in application. The intent is not to stifle innovation or new protocol development but rather to agree on a "state of the art" consistency in application and trap design for comparison of arthropod communities sampled for the SAGE project. Furthermore, the use of a standard protocol series does not preclude the use of additional, more subjective protocols especially where estimates of species richness are desired. Ecosystem Framework The central issue in monitoring and assessment of biotic shifts in ecosystems is our ability to provide spatial-temporal referencing for biotic data. In order to meaningfully analyze biotic shifts associated with climate or anthropogenic change, biotic data must be comparable in space and time and placed within the context of natural ecosystems. Not only must sampling protocols be standardized to permit comparability but the way we record and structure abiotic data associated with the protocols must be standardized, and so too must the ecosystem framework we use to implement a sampling program (Finnamore 1995). One of the fundamental insights arising from the SAGE Workshop is that vegetation in graminoid ecosystems produces a mosaic of multiple scale canopies. That insight structures ecosystems from the perspective of most biodiversity, arthropods. Vegetation architecture, conceptualized as multiple scale canopies, provides an ecosystem framework that may permit identification of analogous components across broad geographic regions. Canopy communities most readily identified in grasslands include trees (usually in the riparian zone), bushes, and several types of herbaceous canopy based on plant height and density. In addition there are also two types of unvegetated community (zero canopy), namely open dune (or blowout) and saline flat. The vegetated canopies reflect a hydrological gradient with trees at the wet end and short grasses and forbs at the dry end. The unvegetated habitats occur either in extreme dry (dunes) or extreme wet (saline ephemeral water basins) conditions. Data acquired using appropriate protocols within this framework may then be compared with analogous communities across gradients within graminoid ecosystems, between graminoid ecosystems, or to analogous communities in non-graminoid ecosystems. The recognition that grasslands may possess several scales of canopies has implications both for the design of a sampling program and for the protocols used to conduct it. For instance canopy sampling protocols should be applied vertically along the aridity gradient within sampling sites (i.e. low and high canopy of tree, bush and herb) and horizontally along the hydrological gradient represented by the transition from riparian zone to the tableland (i.e., tree community to bush community to herbaceous community) or the several heights of canopy represented in the herbaceous communities of a mixed grass prairie. The pulse, or locally transient fauna (the most diverse community assemblage) can then be characterized using specific protocols and not be confused with the fauna of the litter, soil, canopy and aquatic communities which can also be characterized with appropriate protocols used in association with the respective vegetation canopy. Spatial-temporal scale is an important consideration in experimental design. Comparisons of arthropod assemblages can be made temporally over a 24 hour period, over a season, between years, between decades, centuries or millennia; and spatially between zoogeographic regions, ecozones, ecoregions, ecodistricts, SLC polygons, ecosites, plots or microsites. Selection of an appropriate scale in the experimental design has bearing on the abiotic attributes of the ecosystem that could be concurrently monitored to provide meaningful information. Spatial-temporal referencing embodies measurement of climate and landscape with respect to biodiversity. Temporal referencing has traditionally been attempted through recording of the Julian Calendar date of sample collection, but like political boundaries, biota seldom pay attention to them. The Julian date can however be used as a reference to calculate more biologically meaningful statistics which vary over a season and from year to year, like accumulated degree days or accumulated rainfall. Temporal referencing in temperate regions can be partially achieved through the measurement of accumulated degree days and used to account for seasonality in species assemblages within or between sampling sites. In other regions rainfall pattern may achieve better results in accounting for seasonality. Spatial referencing can be accomplished through development of an ecosystem framework for vegetation architecture (i.e., upper canopy of a bush), and the precise georeferencing of sampling sites using Global Positioning Systems and associated data on slope (i.e., 4°) and aspect (i.e., southeast facing). The SAGE Protocols The recommended arthropod sampling protocols and associated abiotic protocols are summarized below. Biological diversity, considered at the species level, is a function of both species richness (number of species) and abundance (number of individuals). All of the protocols provide some qualitative measure (species richness) when applied at a site, and if applied in a consistent manner, can provide data suitable for comparative analysis. Most of the protocols can also provide quantitative measures (abundance) in the form of relative trapability. The Adjunct Protocols are not intended for comparative studies because of collector subjectivity in their application. However, they can provide a check on species richness estimates obtained by other protocols and are especially suited for public partnerships. The protocols selected for a particular study will depend on the hypothesis being tested. Not all protocols are applicable in all situations. If the experiment is designed to look at soil fauna, then clearly the canopy protocols are not applicable. The following summary is considered from the scale of Plot or Ecoelement (see Fox et al. this report) over one season. It provides a quick reference on protocol applicability, placement in the community, operating time, service interval maximum, and an estimate of total samples generated (assuming one application of 5 replicates, where applicable, of the protocol in a community (Plot) over 7 months). Further details on each of the following protocols are presented in the text. Use of all protocols in a single plot over a 7 month season would generate between 2,590 and 2,800 samples. The protocols recommended for most studies are Tullgren extraction, pitfall traps, pan traps, and Malaise traps. Those protocols would generate 1,415 samples from one Plot over a 7 month season. Abiotic Protocols Georeferencing
Climate Monitoring (ITEX Protocols)
Soil Parametres
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pan
traps - 20/month, 7 months = 140.
Combined
total = 280.
