Realm: Terrestrial
Climate: Temperate
Biome: Temperate grasslands, savannas and shrublands
Central latitude: 52.340391
Central longitude: 9.667084
Duration: 2 years, from 1951 to 2009

745 records

194 distinct species

Across the time series Arthaldeus pascuellus is the most frequently occurring species

Methods

Study sites and samplingTo perform a comparative analysis of auchenorrhyn-chan (A), heteropteran (H) and orthopteran (O)communities, we sampled at nine of the original 12sites that were studied between May and October1951 (Marchand 1953). All sites are located nearStolzenau and Leese (Lower Saxony) in the lowlandsof northern Germany. Marchand selected his sitesaccording to a moisture gradient with the result thatthere are three types of habitat (table 1): (i) drygrassland (sites I and II), (ii) mesic grassland (sitesIIIIV) and (iii) moist grassland (sites XXII). Themode and extent of agricultural land use were alsorecorded. Four of the plots were not mown or grazedin 2009, while in 1951 each plot was mown at leastonce a year (table 1). Marchand gave brief descrip-tions of the plant communities present in 1951,which were helpful in rediscovering the plots. Someof these plots have changed severely during the past60 years. Three sites (VII, VIII and IX) had been con-verted to arable fields since 1951 and could not beincluded in the study. In all other cases, sufficientlysimilar habitats were still present to permit sampling.The weather in both sampling periods was largelycomparable: the mean annual precipitation of Ger-many was 751 mm in 1951 and 813 mm in 2009(data received from Deutscher Wetterdienst). Meanspring and summer precipitation slightly differed by7 and 8 mm between both periods. In contrast,mean autumn precipitation was 48 mm higher in2009 when compared with 1951. Mean annual tem-perature rose from 8.7°C in 1951 to 9.2°C in 2009. We sampled eight times at each site beginning inMay and ending in September 2009, trying to matchsampling dates of Marchand as closely as possible(Appendix S1). Marchand sampled with a sweep net(Ø 30 cm; 100 beats per sampling); we used the samemethod and assume that comparisons between yearsare justified. Research has shown that transect sur-veys by different teams at the same sites but on differ-ent routes may produce similar rankings in insectspecies abundance (Schlicht et al. 2009). For A and H,sampling by sweep net is an adequate technique toobtain reliable information about insect communitycomposition and abundance in grassland and scrubhabitats (To ?rma ?la ?1982; Buffington and Redak 1998;Standen 2000). For O, the use of sweep nets is lesseffective and it is recommended to supplement sam-pling with other methods such as acoustical surveys.No other methods besides sweep nets were employedin 1951, and therefore, only sweep nets were used in2009; as a result, information on species identity in Ocommunities should be considered with caution.However, recent work indicates that using sweep netsto sample O can still be valid in comparisons of abun-dance (Gardiner et al. 2005).Only some vegetation samples from the 1950swere available. In 2009, in each site we sampled one10·10 m plot and recorded all vascular plants andan estimate of their cover along with exact localityinformation. We compared aerial photographs of the1950s with photographs from 2008 to assess thedevelopment of the vegetation in the plots and theirimmediate surroundings, i.e. changes in size of ara-ble fields, wood cover and grassland cover. We com-piled relevant life history traits for each speciesbased on the studies by Nickel (2003) and Wach-mann et al. (2004). For A, we examined four traits:degree of host plant specialism (monophagous: onehost plant species; second degree monophagous: one host plant genus; oligophagous: one host plant fam-ily; second degree oligophagous: two host plant fam-ily or up to four host plant species each belonging toup to four different families; polyphagous: varioushost plants from many different families), voltinism(usually one or two generations per year), over-win-tering stage (egg, nymph or adult) and dispersal abil-ity (flightless short-winged brachypterous or mobilelong-winged macropterous morphs). For H, weincluded habitat requirements (preference for dry,mostly dry, dry or wet, mostly wet or wet condi-tions), over-wintering stage (egg or adult; over-win-tering juveniles were not present), feeding type(phytophagous, phytozoophagous or zoophagous)and voltinism. For O, species identity and ecologicalcharacteristics were not considered.

Citation(s)

@Article{BioTIME_cit354, Study_id = {590}, Citation_id = {354}, Author = {Schuch, S. and Brock, J. and Krause, B. and Wesche, K. and Schaefer, M.}, Journal = {Journal of Applied Entomology}, Pages = {321-331}, Title = {Long-term population trends in three grassland insect groups: a comparative analysis of 1951 and 2009}, Volume = {136}, Year = {2012}, Doi = {10.1111/j.1439-0418.2011.01645.x}, Language = {English} }