The Catalan butterfly monitoring scheme has the capacity to detect effects of modifying agricultural practices

Abstract

Citation: Lee, M. S., J. Comas, C. Stefanescu, and R. Albajes. 2020. The Catalan butterfly monitoring scheme has the capacity to detect effects of modifying agricultural practices. Ecosphere 11(1):Abstract. Impacts of agricultural management practices on the receiving environment are seldom suitably assessed because environmental monitoring is costly. In this regard, data generated by already existing environmental survey networks (ESNs) may have sufficient capacity to detect effects. Here, we study the capacity of the Catalan butterfly monitoring scheme (CBMS) to detect differences in butterfly abundance due to changes in agricultural practices. As a model, we compared butterfly abundance across two landscape types according to agricultural intensification. A 2 km diameter buffer area was centered on the CBMS transect, the control group were transects located in areas where intensive agriculture represented <20% of the area; a treated group was simulated by selecting transects located in areas where intensive agriculture occupied an area over 40%. The Welch t-test (a = 0.05 and 80% power) was used to compare butterfly abundance per section across landscape types. The capacity of the t-test to detect changes in mean butterfly abundance, of 12 butterfly indicators relevant to farmland, was calculated annually and for 5-, 10-, and 15-yr periods. Detection capacity of the t-test depended mainly on butterfly data sample size and variability; difference in butterfly abundance was less important. The t-test would be capable of detecting acceptably small population changes across years and sites. For instance, considering a 15-yr period, it would be possible to detect a change in abundance below 10% of the multispecies indicators (all butterfly species, open habitat species, mobile species, and grassland indicators) and two single species (Lasiommata megera and Lycaena phlaeas). When comparisons were carried out within each year, the t-test would only be capable of detecting a change below 30% for all butterfly species, mobile species, and L. megera. However, detection capacity rapidly improved with the addition of further years, and with 5 yr of monitoring, all indicators but Thymelicus acteon had a detection capacity below 30%. We therefore conclude that, from a statistical point of view, the CBMS data "as is" are sensitive enough for monitoring effects of changes in agricultural practices. It could be used, for instance, for the general surveillance of genetically modified crops.

Impacts of Human Activities and Season on Species Diversity and Abundance of Butterflies in Mpanga Kipengere Game Reserve and Surrounding Farmlands, Tanzania

“…Research has indicated that seasons play a role in influencing the quantity and variety of insects present. It is also revealed that during the transition from short to long rains (January to March), we observed a higher number of butterfly species and a greater abundance of them than during the long to short rains transition that is April to June (Figure 5) These findings align with previous research conducted on Kihansi gorge, which found that butterfly species richness and abundance were higher during the dry season compared to other seasons [23].…”

Butterfly communities track climatic variation over space but not time in the Iberian Peninsula

“…In the past century, Mediterreanean regions have been exposed to rapid rates of climate change (Serrano‐Notivoli et al ., 2018, 2019), as well as to contrasting pressures of rural depopulation and land abandonment, versus urbanisation, infrastructure development and agricultural intensification (Debussche et al ., 1999; Rescia et al ., 2010; Serra et al ., 2014; Herrando et al ., 2016). Over recent decades, Mediterranean butterfly communities have responded to climatic warming (Zografou et al ., 2014; Nieto‐Sánchez et al ., 2015) and drying (Herrando et al ., 2019), as well as vegetation encroachment (Ubach et al ., 2020) and changing agricultural practices (Lee et al ., 2020). Some evidence from these regional studies suggests that topographic variation or vegetation cover may counteract effects of climate change on insects (Nieto‐Sánchez et al ., 2015; Herrando et al ., 2019), as has been observed for Mediterranean bird communities (Clavero et al ., 2011; Barnagaud et al ., 2013; Tellería, 2019, 2020).…”

The Fluctuating Asymmetry of the Butterfly Wing Pattern Does Not Change along an Industrial Pollution Gradient

“…Butterflies are valuable environmental indicators because they rapidly and selectively respond even to subtle changes in habitat structure and climate [1,2] (and references therein). Their colorful appearance and aesthetic appeal have attracted attention to these insects from both the general public and decision-makers [3] and have made butterflies focal objects of multiple national and international monitoring schemes [4,5], as well as of citizen science projects (e.g., www.iNaturalist.org (accessed on 20 March 2021)). Because of this attention, butterflies are one of the best studied groups of insects-the Global Biodiversity Information Facility at the beginning of 2019 included over 7.5 million complete and unique records of butterflies from around the globe [6].…”