Composition and diversity of butterflies (Lepidoptera, Papilionoidea) along an atmospheric pollution gradient in the Monterrey Metropolitan Area, Mexico

This study compares the variation of richness, abundance and diversity of butterfly species along an atmospheric pollution gradient and during different seasons in the Monterrey Metropolitan Area, Mexico. Likewise, we analyse the influence of environmental variables on the abundance and richness of butterfly species and quantify the indicator species for each atmospheric pollution category. Based on spatial analysis of the main atmospheric pollutants and the vegetation cover conditions, four permanent sampling sites were delimited. The sampling was carried out monthly in each of the sites using aerial entomological nets and ten Van Someren-Rydon traps during May 2018 to April 2019. A total of 8,570 specimens belonging to six families and 209 species were collected. Both species richness and abundance were significantly different between all sites, except for the comparison between the moderate contamination site and the high contamination site; diversity decreased significantly with increasing levels of contamination. The seasonality effect was absent on species richness; however, for species abundance the differences between dry season and rainy season were significant in each site excepting the moderate contamination site. Regarding diversity, the seasonal effect showed different distribution patterns according to each order. Relative humidity, vegetation cover and three pollution variables were highly correlated with both abundance and species richness. From the total number of species found, only 47 had a significant indicator value. This study constitutes the first faunistic contribution of butterflies as indicators of the environmental quality of urban areas in Mexico, which will help in the development of strategies for the management, planning and conservation of urban biodiversity.

Biomass of generative sphere of Scots pine and drooping birch in the pollution gradient from the Karabash copper smelter on the Ural

Загрязнение лесов сильно влияет на их биологическую продуктивность, но вклад генеративной сферы в нее изучается редко. Наше исследование биомассы генеративных органов деревьев и древостоев сосны обыкновенной и березы повислой проводилось в течение одного вегетационного периода в градиенте загрязнения от Карабашского медеплавильного завода на Южном Урале. Установлено, что максимальная биомасса генеративных органов сосны и березы на уровне как дерева, так и древостоя, приходится на буферную часть градиента загрязнения, в которой древостой, согласно явлению гистерезиса, переходит из одного устойчивого состояния в другое, и на эту же буферную зону приходится максимальная изменчивость биомассы генеративных органов. Полученная закономерность, общая для двух древесных видов, указывает на повышенную адаптивную реакцию массы генеративной сферы деревьев и древостоев на загрязнение в буферной зоне, и можно предположить, что это отражает хорошо известное явление гормезиса в биологии. Высказанное предположение требует углубленного изучения влияния загрязнения на генеративную сферу лесных сообществ. Forest pollution strongly affects their biological productivity, but the contribution of the generative sphere to it is rarely studied. Our study of the biomass of generative organs of trees and stands of Scots pine and drooping birch was performed during one growing season in the pollution gradient from the Karabash copper smelting plant in the southern Urals. It is stated the maximum biomass of generative organs of pine and birch at the level of both a tree and a stand, falls on the buffer part of the pollution gradient, in which the tree stand, according to the phenomenon of hysteresis, passes from one stable state to another one, and the same buffer zone accounts for the maximum variability of the biomass of generative organs. The resulting pattern, common to the two species, indicates an increased adaptive response of trees and stands to pollution in the buffer zone in terms of the mass of the generative sphere and one can suppose it reflects the well known phenomenon of hormesis in biology. This assumption requires in-depth studies of the impact of pollution on the generative sphere of forest communities.

Controls on δ26Mg variability in three Central European headwater catchments characterized by contrasting bedrock chemistry and contrasting inputs of atmospheric pollutants

Magnesium isotope ratios (26Mg/24Mg) can provide insights into the origin of Mg pools and fluxes in catchments where Mg sources have distinct isotope compositions, and the direction and magnitude of Mg isotope fractionations are known. Variability in Mg isotope compositions was investigated in three small, spruce-forested catchments in the Czech Republic (Central Europe) situated along an industrial pollution gradient. The following combinations of catchment characteristics were selected for the study: low-Mg bedrock + low Mg deposition (site LYS, underlain by leucogranite); high-Mg bedrock + low Mg deposition (site PLB, underlain by serpentinite), and low-Mg bedrock + high Mg deposition (site UDL, underlain by orthogneiss). UDL, affected by spruce die-back due to acid rain, was the only investigated site where dolomite was applied to mitigate forest decline. The δ26Mg values of 10 catchment compartments were determined on pooled subsamples. At LYS, a wide range of δ26Mg values was observed across the compartments, from -3.38 ‰ (bedrock) to -2.88 ‰ (soil), -1.48% (open-area precipitation), -1.34 ‰ (throughfall), -1.19 ‰ (soil water), -0.99 ‰ (xylem), -0.95 ‰ (needles), -0.82 ‰ (bark), -0.76 ‰ (fine roots), and -0.76 ‰ (runoff). The δ26Mg values at UDL spanned 1.32 ‰ and were thus less variable, compared to LYS. Magnesium at PLB was isotopically relatively homogeneous. The δ26Mg systematics was consistent with geogenic control of runoff Mg at PLB. Mainly atmospheric/biological control of runoff Mg was indicated at UDL, and possibly also at LYS. Our sites did not exhibit the combination of low-δ26Mg runoff and high-δ26Mg weathering products (secondary clay minerals) reported from several previously studied sites. Six years after the end of liming at UDL, Mg derived from dolomite was isotopically undetectable in runoff.

Using of Taraxacum officinale (L.) pollens for the urban park bioindication

Palinoindication of 6 parks of the urban ecosystem of Kiev using Taraxacum officinale (L.) Weber ex F.H. Wigg. population, was carried out. There is a general trend towards an increase in the amount of nonviable pollen with an increase in anthropogenic load. In the example of T. officinale, this is manifested in a gradual increase to 27% of non-viable pollen on the pollution gradient. With the deterioration of the ecological situation in the studied test polygons, an increase in the number of teratomorphic pollen grains up to 41.10% in Babin Yar tract was recorded. According to the level of palynotoxic action (PE, %), only 2 gradations were revealed in the parks under study: initial and effective. The sublethal effect (highly toxic) has not been established, since the level of pollen sterility in our studies did not exceed 45,2%. The largest number of pollen grains with developmental pathologies (teratomorphic) – 41.10% – was recorded in the Babin Yar tract, the state of which, according to the anthropogenic load index (Jal), is characterized as poor. At the same time, the percentage of teratomorphic pollen grains in T. officinale plants in more favorable environmental conditions (control) does not exceed 16.50%. For the bioindication assessment of the park ecosystems state in the megalopolis, the most indicative were the index of sterility, palynotoxic effect and the content of teratomorphic pollen grains, which increases with the gradient of anthropogenic load.