Birds and butterflies respond to soil‐induced habitat heterogeneity in experimental plantings of tallgrass prairie species managed as agroenergy crops in Iowa, USA

Abstract

Summary The maintenance of habitat heterogeneity in agricultural landscapes has been promoted as a key strategy to conserve biodiversity. Animal response to grassland heterogeneity resulting from spatiotemporal variation in disturbance is well documented; however, the degree to which edaphic variation generates heterogeneity detectable by grassland wildlife has proven more difficult to study in natural settings. We conducted a field experiment to study how soils directly affect vegetation structure and composition and indirectly affect bird and butterfly assemblages using plantings of tallgrass prairie species managed as agroenergy crops in Iowa, USA. The experimental design included four vegetation treatments of varying species richness replicated on three soil types. Habitat characteristics varied widely among soils. Crops on sandy loam, the driest, most acidic soil with the lowest nutrient content, developed shorter, less dense vegetation with sparse litter accumulation and more bare ground compared to crops on loam and clay loam. Birds and butterflies responded similarly to soil‐induced variation in habitat characteristics. Their abundance and species richness were similar on all soils, but their assemblage compositions varied among soils in certain vegetation treatments. In low‐diversity grass crops, bird assemblages using sandy loam were dominated by species preferring open ground and sparse vegetation for foraging and nesting, whereas assemblages using loam and clay loam were dominated by birds preferring tall, dense vegetation with abundant litter. In high‐diversity prairie crops, the species composition of forbs in bloom varied among soils and strongly influenced butterfly assemblages. Synthesis and applications. Prairie agroenergy crops established with identical management practices developed variable habitat characteristics due to natural edaphic variation, and this heterogeneity influenced the spatial distribution of bird and butterfly assemblages due to differential habitat use among species. This finding suggests that if unfertilized prairie crops were grown for agroenergy by land managers large‐scale, soil‐induced habitat heterogeneity would promote wildlife diversity within and among fields, further increasing the habitat value of these crops compared to the fertilized, annual monocultures that currently dominate the agricultural landscape. Our study also highlights the need for managers to consider soil properties when selecting sites to restore grassland habitat for species of conservation concern.

Partitioning abundance‐based multiple‐site dissimilarity into components: balanced variation in abundance and abundance gradients

“…These plots ( n = 48) were the result of an experimental design that included four vegetation treatments of varying tallgrass prairie species richness, replicated on three soil types (see Myers et al . for details). The bird and butterfly data sets were downloaded from Dryad (Myers et al .…”

“…The bird and butterfly data sets were downloaded from Dryad (Myers et al . ). My analyses are by no means a re‐analysis of the original study, but just a simplified example aiming to show (i) the usefulness of separating the two components of abundance‐based multiple‐site dissimilarity, and (ii) the usefulness of comparing incidence‐ and abundance‐based multiple‐site dissimilarity patterns, which could potentially provide different information.…”

“…Density plots representing the distribution dissimilarity indices across 1000 samples of 10 plots with different habitat characteristics (data from Myers et al . ). Components of multiple‐site dissimilarity were computed for birds (red) and butterflies (blue) and for (a) abundance based dissimilarity, where dotted line is total dissimilarity, solid line is the component of dissimilarity due to balanced variation in abundance and dashed line is the component of due to abundance gradients, and (b) incidence‐based dissimilarity, where dotted line is total dissimilarity, solid line is the component of dissimilarity due to species replacement and dashed line is the component of due to nestedness.…”

“…All data used in the case study are openly available from Myers et al . (: Data from: Birds and butterflies respond to soil‐induced habitat heterogeneity in experimental plantings of tallgrass prairie species managed as agro energy crops in Iowa, USA. Dryad Digital Repository.…”

Niches and radiations: a case study on the Andean sapphire‐vented puffleg Eriocnemis luciani and coppery‐naped puffleg E. sapphiropygia (Aves, Trochilidae)

“…We assessed specific ornithological gazetteers (Stephens and Traylor 1983, Paynter 1993 and the above cited publications to Table 1. For example, bird assemblages composition can respond to soil variations (Myers et al 2015), and it is reasonable to expect that such an influence is strong in nectarivorous birds, since soil characteristics have an effect not only on both the yield and sugar concentration of nectar (Kenoyer 1917, Shuel and Shivas 1953, Robacker et al 1983, Farkas et al 2012, Nickless et al 2017) but also on floral traits (Paiaro et al 2012), shaping the plant-pollinator interactions (Meindl et al 2013), and even constituting an important evolutionary force for plants , Yost et al 2012, Rajakaruna 2018). 1.2), which has proven to have better predictive power than other data with regards to precipitation patterns in mountainous areas (Karger et al 2017), for the tropical Andes.…”