Benthic Macroinvertebrates in Streams of the Jaragua State Park (Southeast of Brazil) Considering Multiple Spatial Scales

The study of the distribution of macroinvertebrates, considering multiple hierarchic scales and incorporating different spatial dimensions to assess the role of disturbance in aquatic environments, can contribute to conservation, environmental evaluation and improvement of analytical tools in ecology. The object of this study was to evaluate the diversity of macroinvertebrates in streams of the Jaraguá State Park (SP-Brazil), considering three spatial scales: mesohabitats, segments, and hydrographic basins with different land use parameters (forest, mixed agriculture, organic pollution and deforestation). The samples, collected with a Surber collector, were taken in the beginning of the dry season of 1998. Analysis of data through multiple correspondence analysis showed the importance of variables in macroscale (land use) for the distribution of the fauna in general and the relevance of variability in mesoscale for some taxa in particular. The work points to the necessity of considering different levels of spatial heterogeneity for the conservation of biodiversity in the streams of the park.     

Avian rarity in ten cloud-forest communities in the Andes of Ecuador: implications for conservation

Avian rarity was investigated in ten high-altitude cloud forests in the Andes of Ecuador. Data on species compositions and abundances were obtained by a fully standardized method (standardization for area, altitude, habitat, effort and seasonality). The rare species were isolated from rank-abundance plots on the basis of the quartile definition of rarity. A positive correlation between mean abundances of species and number of sites occupied suggests that high-altitude bird species classified rare by abundance generally can also be classified rare by range. However, it is necessary to be cautious using this result in ranking conservation priorities since the generality is not obeyed by all species. Within the two abundance classes (contains one and two individuals, respectively) represented among the rare species, the one-individual class had significantly more species than the two-individual class. The quantitative rarity of taxa and ecological groupings produced similar results for all sites, while pairwise similarity of rare species between sites was very low. Together with the difficulty of identifying species that are truly rare by abundance, these results imply that sites selected for conservation preferably should be based upon a qualitative evaluation of lists of species referred to vulnerability categories such as endemic, restricted-range, CITES or IUCN threatened/near-threatened species. However, it is necessary also to incorporate other aspects of biodiversity to cover a full range of biotic diversity.     

Impacts of retention felling on coarse woody debris (CWD) in mature boreal spruce forests in Finland

We studied the immediate changes in pre-treatment coarse woody debris (CWD) after retention felling and mechanical site preparation (scarification) in mature Picea abies-dominated boreal forest. Retention felling and scarification were hypothetised to affect the amount of CWD. The disturbance caused to CWD was assumed to depend on species and decay class. Logs were inventoried before fellings, after fellings, and after scarification, estimating the damage percentage for each log. After felling, 7.8% of the total pre-treatment volume of CWD was destroyed in the felled area. After scarification, the decline from pre-treatment volume was 67.6% in the felled area. The amount of CWD decreased also inside the retention tree groups; in the 1st post-treatment season, 4.6% was destroyed of the pre-treatment volume and 20% in the 2nd season. Of the retained trees, 40% were uprooted by the end of the 2nd season. If the majority of the initial downed CWD is destroyed by scarification, as our results show, we can estimate that since scarification became a widely used regeneration method in the 1960s, at least from 4 to 6 million m³ of CWD has already been destroyed in Finland. The role of CWD as a key element for biodiversity in boreal forest is generally accepted, which has led to retention of trees in fellings instead of clear felling. We suggest that at least as important as leaving trees in order to maintain continuum in CWD and species diversity is to preserve existing CWD in fellings over the regeneration phase. This can be done using less destructive harvesting methods, reduced use of scarification and placing retention tree groups in patches with high amounts of CWD.     

Status and Breeding Sites of Three Presumed Endangered Scottish Saproxylic Syrphids (Diptera, Syrphidae)

From 1987 to 1999 efforts were made to understand the status and breeding sites of three presumed endangered flies in Britain: Blera fallax (Linnaeus), Hammerschmidtia ferruginea (Fallén) and Callicera rufa Schummel (Diptera, Syrphidae). Historical data on flight periods, localities and breeding sites were collated from the literature and captured specimens in museums and other collections. Using these data, life cycles were investigated, and cited and other localities searched for adults and early stages. Looking for early stages was more productive than looking for adults. B. fallax is the most endangered. It has declined in abundance, is restricted to two localities and, in 1999, breeding sites were destroyed at one of these localities. In contrast C. rufa is widespread and not uncommon throughout northern Scotland. H. ferruginea is not as endangered as B. fallax but adverse factors such as habitat destruction affect most of its sites.     

30 years brings changes to the arthropod community of Kibale National Park,Uganda

World-wide declines in arthropod abundance and diversity are a major concern, particularly given their importance in ecosystem functioning. Yet, data documenting long-term trends are rare from the tropics, particularly the Afrotropics. Here we evaluate changes in the arthropod communities in Kibale National Park, Uganda across almost four decades. Systematic sweep-net sampling was conducted in two forested sections of the park that had been logged and in one old-growth forest area over 12 consecutive months in 1983/1984 and 2020/2021. This data was augmented with intermittent samples taken in 1986 and 1995. Arthropod abundance declined in all areas, but only significantly so in the moderately logged forestry compartment (41%). Permutational multivariate analysis of variance indicated that community compositions of arthropods differed between the censuses. Understanding the drivers of changes in the arthropod communities is difficult as the system is complex and dynamic. We document an increase in temperature, but no change in rainfall, increases in 11 mammal species, including a marked increase in elephant numbers, and changes in forest structure. We also report on changes in the landscape outside of the park, which includes the human population increasing by a factor of four and agricultural intensification that now includes the use of pesticides. We document that many components of the ecosystem we studied changed simultaneously, which signals that for effective conservation planning, more long-term multi-disciplinary efforts are needed.     

Effects of Clearfell Harvesting on Lucanid Beetles (Coleoptera: Lucanidae) in Wet and Dry Sclerophyll Forests in Tasmania

The effects of commercial forestry harvest and regeneration practices (clearfelling and slash-burning) on the lucanid fauna of the wet sclerophyll forests of southern Tasmania and the dry sclerophyll forests of eastern Tasmania were examined using pitfall catches. Lucanids are saproxylic beetles, dependent on dead, moribund and decaying wood. Samples taken from old-growth forest and from a chronosequence of sites regenerating after logging, in each forest type, were used to compare the species richness and abundance of the lucanid assemblages. In both forest types, species richness and abundance was highest in the youngest regeneration sites (1–3 year), reflecting the species richness of the original and adjacent unlogged forest, lowest in the older (20–25 year) sites, and variable in the old-growth sites. TWINSPAN cluster analysis showed no clear distinction between regeneration and old-growth forest. The post-harvest slash and stump residue provided an important refugium and initial habitat, but our research indicates that some species may not maintain populations in the long term. Our results suggest that most species of lucanids will find a continuous supply of suitable habitat only in old-growth forests; and such species may become less common as clearfell harvesting leads to a replacement of heterogeneous old-growth forest with single-aged monospecific stands. Continuity of supply of wood in all decay stages, the maintenance of sufficient source areas, and biological connectivity between old-growth stands to enable dispersal, are all likely to be essential to maintain lucanid beetle community integrity. If similar principles apply to other saproxylic species of invertebrate, then clearfelling and slash-burning may cause a gradual extinction of an important element of the forest biota.     

Can 'continuity indicator species' predict species richness or red-listed species of saproxylic beetles?

This study investigates the relationship between the abundance of wood-rotting fungus suggested as 'continuity indicator species' and environmental variables for the assemblage of saproxylic (wood-living) beetles associated with Fomitopsis pinicola fruiting bodies in a mature spruce forest in southeastern Norway. The presence of species thought to indicate continuity in old growth is one of the criteria used when finding and delineating small protected areas ('woodland key habitats') in Scandinavian forestry. Although it is clear that remnants of old-growth forest are important for many taxa, documentation as to which entities or species the indicator species indeed indicate is scarce. If stands with a continuous and unbroken input of dead wood have a unique assemblage of wood-rotting fungi, it seems relevant to ask if these stands also have a unique assemblage of rare saproxylic beetles. I find that the indicator species exhibit no significant correlations with beetle species richness or with the presence of red-listed saproxylic beetles as a group. The different characteristics of dead wood conditions are the most important environmental variables that explain both the species richness and the presence of red-listed beetles. Single-species analyses reveal contrasting relationships. The red-listed beetle Atomaria alpina shows a significant and positive association to the abundance of indicator species. Contrary, a group of three red-listed species with similar ecology in the family Cisidae exhibits a significant and negative association to indicator species abundance. This indicates that important patterns are concealed when considering general measures such as overall presence of red-listed beetles. Single-species studies are necessary in order to correctly understand how rare beetles respond to forestry activities and to develop a policy that can secure their continuing existence in the boreal forest.     

Conservation Genetics of Cicindela Deserticoloides, an Endangered Tiger Beetle Endemic to Southeastern Spain

Population surveys of the tiger beetle, Cicindela (Cephalota) deserticoloides, endemic to the few remaining salt steppes of southeastern Spain revealed only four extant colonies. DNA sequencing of some 1896 base pairs of mitochondrial DNA for one specimen each from three populations revealed only a single base pair change confined to a single of the three specimens, thus indicating an extremely low level of differentiation when compared to similar populations of Cicindela (s.l.) elsewhere. Divergence of C. deserticoloides from the closest relatives in the Iberian Peninsula was between 6.9 and 9.9%, attesting to the uniqueness of the species and its high conservation status. Habitat requirements appear to be phylogenetically conserved within Cephalota, but C. deserticoloides seems to be more narrowly confined to relatively drier conditions than its less endangered relatives. The geographic range of the relatives is wider and their local abundance higher, indicating that habitat specialization, low abundance and small geographic range in C. deserticoloides are correlated and in sum are responsible for its vulnerability to extinction.     

Comparison of structure,regeneration and dead wood in virgin forest remnant and managed forest on Grmeč Mountain in Western Bosnia

This paper compares the forest structure, regeneration and distribution of dead wood in a virgin forest remnant and a close-to-nature managed beech–conifer mixture situated on Grme? Mountain in Western Bosnia. The investigations were carried out in a 1 ha permanent sample plot and 35 circular plots (20 m radius) in the virgin forest and in 17 circular plots (25 m radius) in managed forests. The number of trees in the managed forest was significantly (p = 0.05) higher than that in virgin forest and the distribution of the number of trees per diameter classes had a decreasing trend, but with a different shape in the virgin forest compared to the managed stands. In the lower diameter classes, the stock volume recorded in virgin forest was half of that in the managed forest, whilst for higher diameter classes the cumulated volume of the growing stock was almost double in virgin forest. The young crops had a significantly lower presence in the virgin forest and a larger volume of dead wood was identified in the virgin forest than in managed stands. The study results are important in assessing the consequences of close-to-nature management on the forest structure and regeneration when compared to the condition in virgin forests.     

Diversity and rarity hotspots and conservation of butterfly communities in and around the Aokigahara woodland of Mount Fuji,central Japan

In central Japan, Aokigahara woodland is considered to be one of the most natural areas around Mount Fuji and a core area in the conservation of the biodiversity of Mount Fuji. We chose butterflies as an indicator species of biodiversity and examined six communities in and around the woodland in 2000 using transect counts to examine and search for diversity and rarity hotspots and their associated landscapes. The results showed that butterfly species richness and species diversities H 1/ were significantly higher in forest-edge sites than in forest-interior and/or open-land sites, and variation in the total number of species among these three landscape types was well accounted for by ecologically specialist species, such as landscape specifics, oligovoltines, narrow diet feeders and low-density species. Thus, the species regarded as vulnerable to extinction, including Red List species, were observed more often in forest-edge sites than in forest-interior and/or open-land sites. As a result, in the study area, diversity and rarity hotspots were found in forest-edge landscapes. The reasons why butterfly diversity and rarity hotspots were established in forest-edge landscapes were analyzed and interpreted from several points of view, including disturbance level, landscape elements and plant species richness. From these results, and the fact that some species were confined to forest-interior sites, we conclude that it is very important to conserve and manage forest-edge habitats (considered to be semi-natural) as well as forest-interior habitats (considered to be the most natural) to maintain the diversity of butterfly communities and preserve the various types of threatened species in and around the Aokigahara woodland.     

Vascular plant species richness and rarity across a minerotrophic gradient in wetlands of St. Lawrence County,New York,USA

Thirteen wetlands in St. Lawrence County, NY were sampled to examine the effect of a minerotrophic gradient on vascular plant species richness and rarity. Wetlands ranged from organic soil based poor fens (average conductivity 46.40 microsemens, average Ca 3.55 ppm) to mineral soil based rich fens (average conductivity 342.10 microsemens, Ca 23.00 ppm). Vascular plant species richness was sampled during 1990 in randomly located 1.0 m² quadrats. Specific conductivity, presence or absence of hummocks, and water depth predicted 62% of the variation in richness. Richness increased as conductivity increased until 413 microsemens at which a down trend became obvious. The negative curvilinear relation between conductivity and richness is in accordance with the hump-backed model of Grime but occurs at high rather than intermediate conductivity values. State-listed rare species were found in species-rich wetlands only and had a mean associated richness value of 14.50 species m^-2. This relationship should be taken into consideration when selecting wetlands for protection or managing wetlands for maximum plant diversity.     

Better common than rare? Effects of low reproductive success,scarce pollinator visits and interspecific gene flow in threatened and common species of Tibouchina (Melastomataceae)

The reasons for plant rarity have been the focus of many studies, especially because rare species are more prone to extinction than common species. Under the same habitat conditions, rare plants are expected to attract fewer flower visitors and to show some limitation in their reproductive success. Here, using one of the most emblematic Neotropical plant genus (Tibouchina) we tested whether narrow endemic and threatened species in Ecuador have a lower reproductive success or are visited by fewer pollinators than common species, in 13 populations monitored from 2011 to 2013. We also assessed whether interspecific gene flow could be considered a threat to the rare species. However, contrary to expectations, we found that few pollinators visited the flowers, independently of species rarity. Natural outcross pollinations were always very low in all small‐size populations, leading to high levels of pollen limitation. Interspecific crossing experiments also revealed weak reproductive barriers in some species. This study reveals that both narrow and common species of Tibouchina have similar reproductive and pollinator patterns in Ecuador and, therefore, other causes of the rarity of these species should be considered.     

Significance of woodland key habitats for polypore diversity and red-listed species in boreal forests

Preservation of woodland key habitats has become an integral part of biodiversity-oriented forest management in northern Europe. In Finland, brook-side spruce forests constitute the most important key-habitat type in terms of total area and timber volume. Our aim was to compare polypore diversity and the occurrence of red-listed species between brook-side key habitats and comparable sites of managed forest as controls. Furthermore, we assessed the importance of stand structural features to polypore communities, and contrasted regions with different land-use history. Altogether 69 key habitats and 70 controls were inventoried in four regions across southern Finland. A total of 28,023 surveyed dead-wood units had 3,307 occurrences of 114 species of which 25 species were red-listed. Key habitats hosted on average 28% (about two species) more polypore species (mainly deciduous-specialists) than controls because of a larger average volume of dead wood and a higher proportion of dead deciduous wood. However, the average number of red-listed species was low and did not differ between the two forest categories. We detected a landscape effect connected with the intensity and length of forest management history, with the highest numbers of all and red-listed species per site in eastern Finland. Volume and diversity of dead wood were the most important variables explaining variation in species richness. Presently, key habitats in managed forests appear to contribute only little to the conservation of red-listed polypore species.