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Forest ecosystems are important for biodiversity conservation and human societies, but are under pressure due to climate change and human interventions. This applies to natural forests as well as tree plantations. The latter are globally widespread and therefore gaining increasing importance for biodiversity conservation. However, even after dieback due to increasing disturbance frequencies, such plantations are primarily managed for economic returns, leading to growing conflicts among stakeholders. In particular, the impact of forest management on biodiversity is being discussed. This study investigates the effects of five management approaches in a landscape severely affected by spruce (Picea abies L.) dieback on beetle diversity, conservation, and community composition. We considered direct effects of management and indirect effects of environmental parameters separately in ground-dwelling and flight-active beetles. Beetle diversity was strongly affected by forest management, with non-intervention deadwood stands being most beneficial for beetles. In addition, we show indirect effects of environmental factors. In general, parameters related to salvage logging (e.g. open canopies, tree stumps) influenced beetle diversity and conservation negatively, while positive effects were found for soil nutrient availability and plant species richness. Community composition differed strongly among management categories and indicated a lack of landscape connectivity for open habitat species, as we found only low proportions of such species even on salvage-logged sites. We propose a mixture of management approaches after bark beetle outbreaks, including a substantial proportion of non-intervention deadwood stands, to increase landscape heterogeneity and connectivity. This may increase overall biodiversity while addressing the concerns of both forestry and species conservation.

Background Rapid climate changes lead to an increase in forest disturbance, which in turn lead to growing concerns for biodiversity. While saproxylic beetles are relevant indicators for studying different aspects of biodiversity, most are smaller than 2 ​mm and difficult to sample. This, together with a high number of species and trophic roles, make their study remarkably challenging, time-consuming, and expensive. The Landsat mission provides data since 1984 and represents a powerful tool in this scenario. While we believe that remote sensing data cannot replace on-site sampling and analysis, in this study we aim to prove that the Landsat Time Series (TS) may support the identification of insects’ hotspots and consequently guide the selection of areas where to concentrate field analysis. Methods With this aim, we constructed a Landsat-derived NDVI TS (1984–2020) and we summarised the NDVI trend over time by calculating eight Temporal Metrics (TMs) among which four resulted particularly successful in predicting the amount of saproxylic insects: (i) the slope of the regression line obtained by linear interpolating the NDVI values over time; (ii) the Root Mean Square Error (RMSE) between the regression line and the NDVI TS; (iii) the median, and the (iv) minimum values of the NDVI TS. The study area consists of four monitoring sectors in a Mediterranean-managed beech forest located in the Apennines (Molise, Italy), where 60 window flight traps for flying beetles were installed. First, the saproxylic beetle's biodiversities of monitoring sectors were quantified in terms of species richness and alpha-diversity. Second, the capability of TMs in predicting the richness of saproxylic beetles family and trophic categories was assessed in terms of Pearson's product-moment correlation. Results The alpha diversity and species richness analysis indicate dissimilarities across the four monitored sectors (Shannon and Simpson's index ranging between 0.67 to 2.31 and 0.69 to 0.88, respectively), with Landsat TS resulting in effective predictors for estimating saproxylic beetle richness. The strongest correlation was reached between the Monotomidae family and the RMSE temporal metric (R ​= ​0.66). The mean absolute correlation (r) between the NDVI TMs and the saproxylic community was 0.46 for Monotomidae, 0.31 for Cerambycidae, and 0.25 for Curculionidae. Conclusions Our results suggest that Landsat TS has important implications for studying saproxylic beetle distribution and, by helping the selection of monitoring areas, increasing the amount of information acquired while decreasing the effort required for field analysis. [ABSTRACT FROM AUTHOR]

We examined the responses of a beetle assemblage to habitat complexity differences within a single habitat type, Sydney sandstone ridgetop woodland, using pitfall and flight-intercept trapping. Six habitat characters (tree canopy cover, shrub canopy cover, ground herb cover, soil moisture, amount of leaf litter, and amount of logs, rocks and debris) were scored between 0 and 3 using ordinal scales to reflect habitat complexity at survey sites. Pitfall trapped beetles were more species rich and of different composition in high complexity sites, compared with low complexity sites. Species from the Staphylinidae (Aleocharinae sp. 1 and sp. 2), Carabidae (Pamborus alternansLatreille), Corticariidae (CartodereThomson sp. 1) and Anobiidae (MysticephalaFord sp. 1) were most clearly responsible for the compositional differences, preferring high complexity habitat. Affinities between general functional groupings of pitfall-trapped beetles and habitat variables were not clear at a low taxonomic resolution (family level). The composition and species richness of flight-intercept-trapped beetles were similar in high and low complexity sites. Our study demonstrates that discrete responses of the various functional groups of beetles are strongly associated with their feeding habits, indicated by differing habitat components from within overall composite habitat complexity measures. Although habitat preferences by beetle species may often reflect their foraging habits, clarification of the causal mechanisms underpinning the relationships between habitat complexity and beetles are critical for the development of general principles linking habitat, functional roles and diversity. [ABSTRACT FROM AUTHOR]

Abstract. Herbivorous beetles were sampled in central Slovakia and in the Tatra Mountains of northern Slovakia from seven different Salix species which are partly characterized by smooth leaves containing phenolic glycosides and partly by hairy leaves containing tannins. The collection included about 8000 individuals representing 129 species. Of the 129 species, 77 species are able to use the willows as hosts; the remaining 52 ‘tourist’ species comprise less than 3% of the collected individuals. The data on species richness and abundance did not generally support the ‘feeding specialization’ hypothesis. The proportion of specialized (= monophagous and oligophagous) beetles feeding on willows of both morphological and biochemical groups was in the same range. Host plants of the two groups could support high diversity and high evenness values, even when leaf characteristics and plant chemicals largely influenced species assemblage. The region in which the willow trees grow had a considerable impact on host plant use. Generalist beetle species predominated in central Slovakia. By contrast, in the Tatra Mountains, specialist feeders which are able to use phenolic glycosides to their advantage were predominant. The number of species and the total density of individuals collected from willows containing phenolic glycosides (S. fragilis and S. purpurea ) did not usually vary between the two regions. In contrast, fewer species and individuals were found in the Tatra Mountains when they settled on willow species containing tannins (S. caprea and S. cinerea ). Also, the phylogenetic status of host plants affected species assemblages. In central Slovakia willow species of the subgenus Vetrix (S. purpurea, S. caprea and S. cinerea ) generally showed a higher beetle diversity (Hs ) than species of the subgenus Salix (S. fragilis, S. alba and S. triandra ), although both subgenera comprise species of both morphological and biochemical... [ABSTRACT FROM AUTHOR]

1. Up to 50% or more of the savanna landscapes of northern Australia are burnt each year, but the effects of these fires on savanna faunas are poorly known, especially for arthropods. 2. We investigated the responses of grass-layer beetles to three fire regimes (unburnt — fires excluded; early — annual fires lit early during the dry season; late — annual fires lit late during the dry season) as part of a landscape-scale fire experiment at Kapalga in Australia's Northern Territory, where replicated fire regimes were applied to 15-20-km[sup 2] landscape units over a 5-year period. We also sought to identify beetle species that might act as indicators of particular fire regimes, and examined the extent to which analysis at the family level is sufficient to reveal patterns evident from species-level analysis. 3. Beetles were sampled using sweep nets during February (mid-wet season) and May (end of wet season) each year, from 1989 (18 months prior to the imposition of fire treatments) to 1995 (after 5 years of treatments). 4. A total of 3865 beetles from 233 species was recorded, with the dominant families Chrysomelidae (leaf beetles) and Curculionidae (weevils) contributing 91% of all beetles and 57% of total species. 5. Total beetle abundance, species richness, family richness and the abundances of one of the 10 most common species were significantly affected by fire treatment according to ANOVA. In all cases, beetle abundance and richness were similar in the two burning treatments, but greater than in the unburnt treatment. These differences were only apparent during the second half of the experiment. The responses were mirrored by changes in composition at species, family and guild levels, according to multivariate analysis. 6. According to indicator analysis, five beetle species were significant indicators of late fires, and one of early fires. All these species were infrequently recorded and therefore of limited use for management. However,... [ABSTRACT FROM AUTHOR]

The article presents a study that examines how ground-active beetles respond to savanna fires and how detection of these responses is contingent upon the amount of rain occurring prior to sampling. Also tested is the extent to which family-level responses are taxonomically sufficient to reveal responses detected at the species level. It cites the importance of understanding of the impact of different fire management regimes.