Changes In Species Composition Research Articles

Loss of native herbivores triggers diversity decline of ephemeral plant communities

AbstractAimEvaluate the temporal changes in species diversity, composition, and structure of ephemeral plant communities and the seed bank in response to long‐term herbivore exclusion over 11 years in plots with and without herbivores.LocationNorth‐central Chile.MethodsWe obtained information on ephemeral vegetation cover in August and September using the intercept point method and recorded seed abundance in April. The Bosque Fray Jorge National Park Long‐Term Socio‐Ecological Research (LTSER) provided these records covering 11 years (2009–2019). From the original experiment of 20 plots, we used eight plots divided into two treatments: four plots allowed free access to all herbivores (with herbivores), while the other four plots excluded herbivores (without herbivores).ResultsWe found that Hill–Shannon diversity increased in plant communities with herbivores and a temporal increase in the cover of the dominant species, Plantago hispidula, under herbivore exclusion. In wet years, species richness and temporal turnover of plant communities increased independently of treatment. Although seed abundance differed among treatments and years, population structure remained constant over time and among treatments, suggesting that the seed bank acts as a buffer against shocks that modify plant community dynamics. Structural equation modeling revealed that precipitation, via its positive effects on Plantago hispidula, increases native plant richness to a greater extent than herbivores. However, in the absence of herbivores, precipitation directly affects native species richness. Moreover, we found that precipitation also influences the native species richness of the seed bank, both directly and indirectly, although its impacts exhibit a time lag.ConclusionsOur study demonstrates that the temporal dynamics of ephemeral plant communities and seed banks in semi‐arid ecosystems are strongly coupled to climate variability, highlighting the vulnerability of these communities to biodiversity loss and climate change.

Revisiting Alwyn H. Gentry’s forest transect data: latitudinal beta diversity patterns are revealed using a statistical sampling-model-based approach

Gentry’s forest transect data have been frequently used to assess global patterns of plant diversity and plant species compositional changes along environmental and geographical gradients. Based on the worldwide woody plant abundance records from Gentry’s 197 localities/plots (each consisting of ten 2 m × 50 m subplots/transects), we apply a recently developed sampling-model-based standardization method (iNEXT.beta3D standardization) to examine how beta diversity among subplots varies with latitude. Beta diversity quantifies the extent of among-subplot differentiation which represents the interacting effect of species abundance distribution and spatial aggregation. Here beta diversity is obtained by a multiplicative decomposition scheme based on the framework of Hill numbers of any order q ≥ 0. Under statistical sampling models, data in nearly all of the 197 localities were incomplete, i.e., there were species present in the assemblage but undetected in the data. For Gentry’s data collected along narrow transects, the dependence among sampled individuals due to spatial aggregation is generally weak. The observed beta diversity depends on the among-subplot differentiation and sampling effort/completeness, which in turn induce dependence of the observed beta diversity on alpha and gamma diversity. To control for sampling effort/completeness, the iNEXT.beta3D method standardizes both alpha and gamma diversity at the same level of sample coverage to formulate coverage-based beta diversity. The resulting standardized beta diversity provides a statistical solution to remove the dependence of beta diversity on both alpha and gamma diversities, and thus reflects the pure among-subplot differentiation. The coverage-based standardization reveals latitudinal beta diversity patterns/trends not only for richness-based, but also for abundance-sensitive beta diversity.

Challenges towards the Sustainability and Enhancement of the Indian Sundarban Mangrove's Blue Carbon Stock.

The Sundarban is the world's largest contiguous mangrove forest and stores around 26.62 Tg of blue carbon. The present study reviewed the factors causing a decline in its blue carbon content and poses a challenge in enhancing the carbon stock of this region. This review emphasized that recurrent tropical cyclones, soil erosion, freshwater scarcity, reduced sediment load into the delta, nutrient deficiency, salt-stress-induced changes in species composition, mangrove clearing, and anthropogenic pollution are the fundamental drivers which can potentially reduce the total blue carbon stock of this region. The southern end of the Ganges-Brahmaputra-Meghna Delta that shelters this forest has stopped its natural progradation due to inadequate sediment flow from the upper reaches. Growing population pressure from the north of the Sundarban Biosphere Reserve and severe erosion in the southern end accentuated by regional sea-level rise has left minimal options to enhance the blue carbon stock by extending the forest premises. This study collated the scholarly observations of the past decades from this region, indicating a carbon sequestration potential deterioration. By collecting the existing knowledge base, this review indicated the aspects that require immediate attention to stop this ecosystem's draining of the valuable carbon sequestered and, at the same time, enhance the carbon stock, if possible. This review provided some key recommendations that can help sustain the blue carbon stock of the Indian Sundarban. This review stressed that characterizing the spatial variability of blue carbon with more sampling points, catering to the damaged trees after tropical cyclones, estuarine rejuvenation in the upper reaches, maintaining species diversity through afforestation programs, arresting coastal erosion through increasing sediment flow, and combating marine pollution have become urgent needs of the hour. The observations synthesized in this study can be helpful for academics, policy managers, and decision makers willing to uphold the sustainability of the blue carbon stock of this crucial ecosystem.

Current management in national and state forests has important but limited impacts on sustaining oaks in temperate forests of the eastern U.S

Active management for promoting oaks (Quercus spp.) and restraining maples (Acer spp.) is mostly conducted in public forests (e.g., national forests [NF] and state forests [SF]) because of oaks' ecological and economic importance. Studies have shown that current management efforts have limited success, meanwhile, oak-dominant forests continue to shift in composition and structure to shade-tolerant, fire-sensitive mesophytic species (e.g., red maple A. rubrum). It remains to be evaluated whether current management can achieve its objectives in public forests and at regional scales. In this study, we investigated the long-term outcomes of business-as-usual (BAU) and alternative management (AltMgt) scenarios in a large, temperate hardwood forest landscape in southern Ohio, US. The BAU approach simulates contemporary management, informed by harvest records across public lands and a geospatial disturbance database (i.e., LANDFIRE) to infer private land management. Whereas the AltMgt scenario increases the pace and scale of forest management on public lands through two-stage oak shelterwood harvests, treated every ten years across 10% of the land area with private land remaining as BAU. We used a spatially explicit and dynamic forest landscape model to project species compositional and structural changes under these two scenarios. Our results demonstrate that BAU management in public forests may not successfully sustain oak but instead favors the colonization of maples. Further, management objectives to promote oaks could be achieved on public forests under the AltMgt scenario, but such alternative management had limited impacts at the regional scale when including private lands. The management of NF and SF has a crucial role in driving regional changes in oak and maple abundance, particularly when private lands continued their BAU management. Starting conditions by landownership are also important considerations for oak-maple dynamics through time, implying the need to have a range of priorities and objectives, under different time frames, when developing long-term conservation plans for oak forests at regional-scales.

An experimental approach to identify drivers of tree regeneration diversity, composition, and heterogeneity in northern hardwood forests

Silviculture methods such as clearcutting, shelterwood seed cutting, and selection system are used to manipulate the canopy and regenerate new cohorts in hardwood stands. Additionally, site preparation can be utilized to alter seedbed conditions with the aim to promote changes in species composition. However, limited seed availability and increased ungulate browsing may limit successful natural regeneration in some areas. Our objective was to investigate the influence of regeneration method, site preparation, deer exclusion, and direct seeding on the regeneration of a managed northern hardwood forest. Utilizing a randomized split-plot design with three splitting levels, we examined the effects of four different regeneration methods, two site preparation treatments, seed limitation and deer browsing on composition, compositional heterogeneity, and richness of regenerating tree species. We observed significant differences in the resulting species composition related to the regeneration and site preparation methods. Shelterwood seed cutting implemented with 60% and 30% residual canopy cover, along with scarification, increased species richness and species compositional heterogeneity. However, the combination of deer exclusion and direct seeding resulted in the highest species richness across all treatment combinations. Deer exclusion alone did not enhance richness or compositional heterogeneity, highlighting the impeding effect of limited seed availability. We found that direct seeding successfully altered species composition and increased species richness. Our results suggest that while the regeneration and site preparation methods can benefit natural tree regeneration, approaches that also address both seed limitations and deer browsing will be necessary to increase the tree species diversity in some cases.

The Ecological Quality Status Assessment of Marine and Transitional Ecosystems: New Methods and Perspectives for the Future

Worldwide legislation emphasizes the need to monitor the health of aquatic ecosystems based on the response of biological quality elements to environmental conditions. A plethora of methodologies have been suggested in this sense. Lately, substantial efforts have led to the exploration of new biological quality elements from the meiobenthic compartment and the implementation of new methodologies based on environmental DNA. Due to their short life-cycles, meiofaunal organisms respond quickly to environmental variability. Changes in population dynamics and species composition are indicative of changes in environmental conditions. Recent pioneer studies have shown that biotic indices based on benthic foraminifera and nematodes can efficiently assess the health of transitional and marine ecosystems. The use of environmental DNA, as well as other fingerprinting techniques, is increasing in biomonitoring studies, and further calibrations are still needed to implement this method. The published papers in this Special Issue represent well the wide applicability of meiobenthic groups, i.e., benthic foraminifera and nematodes, allowing us to address a key ecological knowledge gap in order to convince decision makers and stakeholders about the advantage of introducing new biological quality elements in environmental biomonitoring.

Galling insect communities mediate the effects of fire on their associated parasitoid communities

Abstract Understanding fire effects on multitrophic levels is critical to the context of changes in fire regime and climate. Insects located at higher trophic levels, like parasitoids, are more vulnerable to habitat changes than insect herbivores because they need well‐established populations of their hosts to survive. Currently, fire effects on parasitoids and their interactions with their hosts are unknown. Our aim was to study the changes in abundance, richness and species composition, as well as the food web structure in a system involving parasitoids and galling insects under different fire scenarios. We asked whether potential changes in abundance, species richness and composition of parasitoid communities are explained by galled plant abundance, species richness and composition of galling insects, and how fire affects the structure of galling insect–parasitoid food webs. The highest parasitoid richness was found in the 9 years after fire scenario, whereas parasitoid abundance was not affected by fire. The parasitoid species composition in the 9 years after fire scenario was different from that in the unburned and 3 years after fire scenarios. Parasitoid communities were modulated by galled plant abundance, species richness and composition of galling insect communities. Vulnerability was significantly higher in 9 years after fire scenarios, but it increased with increasing network size. Fire affects the community of parasitoids through changes in their host communities. Differences in exclusivity to fire scenarios and diet specialisation of parasitoid species and galling insect richness may explain the patterns found. Our study supports evidence that fire creates habitats heterogeneous in the availability of hosts shaping the parasitoid communities, with a bottom‐up effect in food webs. Additionally, in burned areas were recorded unique galling insect–parasitoid interactions.

Monitoring montane-subalpine forest ecotone in the Pyrenees through sequential forest inventories and Landsat imagery

Key messageAbies alba Mill.–Pinus uncinata Ramond. ecotone dynamics are examined along both altitudinal and protection level gradients by combining field inventories and Landsat data. An upward expansion of A. alba to the subalpine belt is observed in the last decades as a result of stand maturation after logging cessation.ContextHigh-mountain forests constitute sensitive locations to monitor the impacts of global change on tree-species composition and ecotone dynamics. In this study, we focus on the Spanish Pyrenees where silver fir (Abies alba Mill.) coexists with mountain pine (Pinus uncinata Ramond.) forming montane-subalpine ecotones.AimsThe main goal of this study is to assess the spatiotemporal dynamics of the silver fir–mountain pine ecotone and its underlying driving factors.MethodsWe reconstructed the spatial distribution and dynamics of the species by combining remote sensing imagery and field plot data from 1989 to 2015, employing support vector machine techniques for image classification. Using variance analysis and mixed effects models, we then analyzed the evolution of basal area and replacement index, a measure of relative change in species composition, over time and altitude range. Additionally, we explored their relationship with site factors and protection level (National Park vs. protection buffer zone).ResultsSilver fir has expanded its distribution in both the National Park and the protection buffer zone, whereas mountain pine has remained stable. Both species exhibit increased basal area associated with stand maturation and a higher level of protection. The replacement index indicates a rise in silver fir in the understory on North-facing slopes, attributed to stand densification. These findings are particularly noticeable in the area with the highest level of protection.ConclusionThe cessation of traditional land uses has led to ongoing stand densification, promoting succession and favoring the increased abundance of silver fir at its uppermost locations, where this species outcompetes mountain pine.

Characterisation of Anopheles species composition and genetic diversity in Meghalaya, northeast India, using molecular identification tools.

Malaria in India is declining, in part due to the use of long-lasting insecticide-treated nets (LLINs) and vector control. Historically, the north-eastern region of India has contributed ~10%-12% of the nation's malaria burden. The important mosquito vectors in northeast India have long been considered to be Anopheles baimaii and An. minimus, both associated with forest habitats. Local deforestation and increased rice cultivation, along with widespread LLIN use, may be changing vector species composition. Understanding if and how vector species composition is changing is critical to successful malaria control. In Meghalaya state, malaria is now at a low level of endemicity with occasional seasonal outbreaks. In a biodiverse setting like Meghalaya, where >24 Anopheles mosquito species have been recorded, accurate morphological identification of all species is logistically challenging. To accurately determine Anopheles species richness in the West Khasi Hills (WKH) and West Jaintia Hills (WJH) districts, adult and larval mosquitoes were collected and identified using molecular methods of allele-specific PCR and cytochrome oxidase I DNA barcoding. In 14 villages across both districts, we identified high species richness, 19 species in total. Molecular findings indicated that An. minimus and An. baimaii were rare, while four other species (An. maculatus, An. pseudowillmori, An. jeyporiensis and An. nitidus) were abundant. Anopheles maculatus was highly prevalent in WKH (39% of light trap collections) and An. pseudowillmori in WJH (45%). Larvae of these four species were found in rice fields, suggesting that land cover change is influencing species composition change. Our results suggest that rice fields might be contributing to the observed abundance of An. maculatus and An. pseudowillmori, which could be playing a role in malaria transmission, either independently due to their high abundance, or in combination with An. baimaii and/or An. minimus.

Vegetation responses to pathogen-induced tree loss: Swedish elm and ash forests revisited after 32 years

Invasive fungal pathogens are an increasing problem globally and can cause strong effects on forest ecosystems. In this study, we contrast vegetation surveys in eutrophic elm (Ulmus glabra) and ash (Fraxinus excelsior) forests in southern Sweden, conducted just prior to the arrival of Dutch elm disease (DED) in 1989, and then again in 2021, several years after ash dieback (ADB) began. At the sample plot scale, species richness (α–diversity) of the upper tree layer strongly decreased from 1989 to 2021, and the mean cover of elm decreased from 27 to 1% and of ash from 29 to 13%. In the lower tree and shrub layers, elm and ash were replaced by other, mainly shade-tolerant, tree species. The cover and richness of the shrub layer increased in previously elm-dominated stands but not in ash-dominated stands. The extensive loss of canopy cover in elm stands caused a larger change in upper tree layer species composition and increased compositional variability (β-diversity) between plots when compared to the ash stands. The direction of the changes in tree layer composition between the surveys varied with soil moisture and nutrient availability. While beech increased in less eutrophic plots, more nutrient-rich plots changed toward hornbeam or small-leaved lime, and wetter plots turned toward alder and bird cherry. Hence, our results indicate increased compositional diversity and alternative successional pathways for community reorganization following DED and ADB. Future research will reveal if these pathways will later merge or further split.

The Mechanical Stability of Pure Norway Spruce Stands along an Altitudinal Gradient in the Czech Republic

Norway spruce stands are established and managed along various site conditions in central Europe. Currently, spruce often grows at locations outside of its ecological optimum, resulting in extensive damage elicited by harmful abiotic and biotic factors, which relatively shortens the time to change this adverse status in the adaptation frame by foresters. Except for the rapid change in species composition through clear-cuts, another way is possible, i.e., stabilising current (especially young) spruce stands to extend the time required to implement adaptation measures. The assumption that different site conditions will have to be respected as part of this adaptation was confirmed by our study based on NFI data of the Czech Republic. A semiparametric generalized linear model (GAM) was used to model the relationship between the height-to-diameter ratio and forest stand age, differentially considering particular forest vegetation zones. Spruce stands with lower elevations attain a lower stability (expressed by their height-to-diameter ratio; HDR) than those in the mountains. The HDR culminated in lower and middle altitudes in the first half of the rotation period, representing the most critical timing and effectivity of silvicultural measures. Contrary to previous findings, we found higher HDR values at nutrient-rich sites than those at acid ones, especially up to 50–60 years old. Therefore, more research should be devoted to the issue concerning the same thinning regime under different site conditions.

Composition and Long-Term Variation Characteristics of Coral Reef Fish Species in Yongle Atoll, Xisha Islands, China.

Yongle Atoll was the largest atoll in the Xisha Islands of the South China Sea, and it was a coral reef ecosystem with important ecological and economic values. In order to better protect and manage the coral reef fish resources in Yongle Atoll, we analyzed field survey data from artisanal fishery, catches, and underwater video from 2020 to 2022 and combined historical research to explore the changes in fish species composition and community structure in Yongle Atoll over the past 50 years. The results showed that a total of 336 species of fish were found on Yongle Atoll, belonging to 17 orders and 60 families. Among them, Perciformes had the most fish species with 259 species accounting for 77.08% of the total number of species. The number of fish species in the coral reef of Yongle Atoll was exponentially correlated with its corresponding maximum length and significantly decreases with its increase. The fish community structure of Yongle Atoll changed, and the proportion of large carnivorous fish decreased significantly, while the proportion of small-sized and medium-sized fish increased. At the same time, Yongle Atoll has 18 species of fish listed on the IUCN Red List, 15 of which are large fish. The average taxonomic distinctness (Delta+, Δ+) and the variation taxonomic distinctness (Lambda+, Λ+) in 2020-2022 were lower than the historical data, and the number of fish orders, families, and genera in Yongle Atoll has decreased significantly, which indicates that the current coral reef fish species in Yongle Atoll have closer relatives and higher fish species uniformity. In addition, the similarity of fish species in Yongle Atoll was relatively low at various time periods, further proving that the fish community structure has undergone significant variation. In general, due to multiple impacts, such as overfishing, fishing methods, environmental changes, and habitat degradation, the fish species composition of Yongle Atoll may have basically evolved from carnivorous to herbivorous, from large fish to small fish, and from complexity to simplicity, leaving Yongle Atoll in an unstable state. Therefore, we need to strengthen the continuous monitoring of the coral reef ecosystem in Yongle Atoll to achieve the protection and restoration of its ecological environment and fishery resources, as well as sustainable utilization and management.

Interactive effects of warming and eutrophication on zooplankton could reverse the stoichiometric mismatch with phytoplankton

The core ecosystem functioning (e.g. trophic transfer efficiency) is at risk of being disrupted by the growing mismatch between nutrient content of primary producers and nutrient demand of grazing consumers. Ecological stoichiometry provides a conceptual framework that explains this trophic interaction using C, N and P elemental composition across trophic levels. In light of ongoing climate change and eutrophication, previous studies have raised concerns regarding the growing stoichiometric mismatch between phytoplankton and zooplankton, given the stoichiometric plasticity of phytoplankton. However, there is currently little conclusive evidence on the stoichiometric mismatch from a dual perspective of phytoplankton and zooplankton. To address this, we conducted a mesocosm experiment to investigate the separate and combined effects of climate warming (a constant increase of +3.5 ​°C plus heat waves) and eutrophication (nutrient addition) on stoichiometric mismatch between phytoplankton and zooplankton by examining stoichiometric changes in both communities. We observed a growing trend in stoichiometric mismatches when warming or nutrient addition acted individually, which was mediated by the increase in nutrient demand (N, P elements) of zooplankton growth. However, when these stressors acted jointly, the mismatches were reversed. This could be because climate warming and eutrophication combined would lead to changes in species composition, which accordingly reshaped the stoichiometric composition at the community level. These results illustrate the need of stoichiometric mismatches for understanding the implication of global change on trophic interactions and ecosystem functioning, requiring consideration not only of cross-trophic levels but also of compositional changes within communities.

A Baltic pelagic fish community revisited: Indications of profound changes in species composition in the Stockholm Archipelago

While the central Baltic herring (Clupea harengus) stock biomass is estimated to have been reduced by ∼80 per cent since the 1970 s, the local effects of this decline remain unassessed. Coastal commercial fishermen have witnessed a widespread depletion at the spawning grounds and generally low herring abundance in inshore areas. We carried out hydroacoustic surveys, supported by midwater trawling in August 2021, to test whether herring abundance and recruitment have changed over time in the inshore areas. We used assessed recruitment success, measured as young-of-the-year (YOY) abundance, as a proxy for herring abundance in several areas of the southeast Stockholm Archipelago and compared the results with previous investigations in this area (hydroacoustics 2000–2001 and midwater trawling 2002–2004 monitoring). We found that the composition of the fish community had undergone significant changes. While acoustic backscattering (sA) representing the whole fish community were similar to previous estimates, species composition was significantly changed. YOY herring, previously dominant, had declined from 55% to 4% in numbers, whereas three-spined stickleback (Gasterosteus aculeatus) increased from no representation to 76%. The observed changes makes it imperative that further investigation concerning herring population structure, biomass, and recruitment are conducted.

Spatio-temporal modelling of the effect of environmental and land-use factors on species-rich calcareous grasslands

The abundance of sensitive plant species in calcareous grasslands is threatened by agricultural intensification with nutrient addition and increased livestock densities as well as by land abandonment. The Hill-Shannon diversity is decreasing, and the species composition of Danish calcareous grassland is generally unstable and is expected to experience further change in the coming years. In order to quantify the effects of selected environmental and land-use factors on the observed variation and changes in the vegetation of calcareous grasslands, large-scale spatial and temporal pin-point plant cover monitoring data are fitted in a structural equation model. The analyzed vegetation data come from 100 Danish sites monitored over an eight-year period. The important sources of measurement and sampling uncertainties have been included using a hierarchical model structure. Furthermore, the measurement and sampling uncertainties are separated from the process uncertainty, which is important when generating ecological predictions that may feed into local conservation management decisions. There were significant negative effects of grazing and nitrogen deposition on the change in cover of sensitive plant species. Whereas the negative effect of nitrogen deposition on the cover of sensitive species was expected, it was surprising that the model results suggest that sensitive species may be subjected to overgrazing by the grazing regimes that are currently applied at protected Danish calcareous grasslands. The standardized regression coefficients suggest that the effects of both grazing and nitrogen deposition are relatively benign compared to the effects of soil type, soil pH and precipitation. The relatively large effect of precipitation is interesting, since it is predicted that the amount of precipitation and its distribution over the seasons will change due to climate change, and the results suggest that climate change may lead to important species compositional changes in calcareous grasslands. The fitted model may be used to quantify the uncertainties when generating ecological forecasting and local adaptive management plans. More specifically, this study suggests that it is relevant to rethink the currently used criteria for vegetation height when assessing the conservation status of calcareous grasslands.

Dynamics‐based characterization and classification of biodiversity indicators

AbstractVarious biodiversity indicators, such as species richness, total abundance, and species diversity indices, have been developed to capture the state of ecological communities over space and time. As biodiversity is a multifaceted concept, it is important to understand the dimension of biodiversity reflected by each indicator for successful conservation and management. Here we utilized the responsiveness of biodiversity indicators' dynamics to environmental changes (i.e., environmental responsiveness) as a signature of the dimension of biodiversity. We present a method for characterizing and classifying biodiversity indicators according to environmental responsiveness and apply the methodology to monitoring data for a marine fish community under intermittent anthropogenic warm water discharge. Our analysis showed that 10 biodiversity indicators can be classified into three super‐groups based on the dimension of biodiversity that is reflected. Group I (species richness and community mean of latitudinal center of distribution (cCOD)) showed the greatest robustness to temperature changes; Group II (species diversity and total abundance) showed an abrupt change in the middle of the monitoring period, presumably due to a change in temperature; Group III (species evenness) exhibited the highest sensitivity to environmental changes, including temperature. These results had several ecological implications. First, the responsiveness of species diversity and species evenness to temperature changes might be related to changes in the species abundance distribution. Second, the similar environmental responsiveness of species richness and cCOD implies that fish migration from lower latitudes is a major driver of species compositional changes. The study methodology may be useful in selecting appropriate indicators for efficient biodiversity monitoring.

Cross-stress lipid response of Tetraselmis striata CTP4 to temperature and salinity variation

Tetraselmis striata CTP4 is a euryhaline, eurythermal microalga, rich in lipids, including omega-3 polyunsaturated fatty acids. However, little is known about how salinity and temperature affect its lipid profile. This work sought to evaluate the plasticity of the lipidome of T. striata CTP4 grown under different combinations of salinity (5, 20 and 35 ppt) and temperature (10, 20, 30 and 40 °C) by gas-chromatography and liquid-chromatography coupled to mass spectrometry. High salinity reduced phospholipid and glycolipid content and upregulated diacylglyceryl hydroxymethyltrimethyl-β-alanine betaine lipids at 20 °C. Accumulation of omega-6 fatty acids was observed at higher temperatures, with changes in glycolipid composition and reduction of lipid species esterified to polyunsaturated fatty acids. T. striata CTP4 grown at 40 °C had higher triacylglycerol productivity, although imposing severe limitations on its survival. Overall, the different combinations of salinity and temperature allowed the production of biomass with dissimilar lipid composition and nutritional value with promising biotechnological applications.

What is a suitable management for Typha latifolia control in wet meadows?

AbstractAimTypha latifolia causes serious problems in wet meadows by overgrowing and suppressing other native plants. To determine suitable management for T. latifolia control, we addressed the following question: What are the effects of long‐term cutting at different frequencies (once or twice per year and no management) and biomass removal on cover and other characteristics of T. latifolia, and on sward productivity and plant species composition?LocationMalá Strana nature reserve, Jizerské hory Mountains, Czechia.MethodsA long‐term experiment arranged in a randomised block design with three blocks was established in 2005. Data were collected from five treatments: unmanaged control; cutting once a year in June without biomass removal and with biomass removal; cutting twice per year in June and August without biomass removal and with biomass removal. Percentage cover of T. latifolia and other vascular plant species was visually estimated and T. latifolia characteristics (tiller density, height, dry‐matter biomass [DMB] yield and litter), sward height and DMB yield were measured during 2005–2018 at the end of June.Results and DiscussionRegular cutting once or twice per year regardless of cut biomass removal led to reductions in tiller density, height, litter and DMB yield of T. latifolia. Biomass removal had only a slight tendency to affect T. latifolia characteristics. The higher frequency of cutting significantly decreased the mean T. latifolia cover, litter and DMB yield. Cutting once or twice per year regardless of biomass removal led to successive changes in plant species composition but had no effect on the species richness and evenness.ConclusionsCutting at least once per year without biomass removal seems to be sufficient to achieve a decrease in DMB yield and litter of T. latifolia plants, and thereby maintain the wet‐meadow vegetation without loss of species richness and also preventing the overgrowth of shrubs and trees.

Catalogue of the entomological collection of the Division of Zoology of the Faculty of Science in Zagreb, collection of family Coccinellidae (Insecta: Coleoptera)

Entomological collections are an invaluable source of data, due to the variety of species they contain, capturing the biodiversity of a given time. Thus, the entomology part of the Division of Zoology Collection (Faculty of Science, Department of Biology), in Zagreb, established in 1890, is an important asset for all faunistic research and any overview of historical changes in species composition, as well as an important resource in the education of young scientists. Here we provide records of 198 ladybird specimens belonging to five tribes and 24 taxa. Coccinella septempunctata Linnaeus, 1758 and Hippodamia (Hemisphaerica) tredecimpunctata (Linnaeus, 1758) were the most abundant species in the collection, with 59 and 40 specimens respectively. The altitudinal range for the specimens in the collection is 10–1031 m a.s.l., with most records having been found between 10 and 199 m a.s.l. Due to the educational and scientific importance of entomological collections, it is recommended that the review and inventory of the entomological material within the Division of Zoology Collection be continued.

Climate change is enforcing physiological changes in Arctic Ecosystems

Remote sensing and site-level observations have shown unprecedented changes in Arctic ecosystems owing to climate warming. These observations include greening and browning trends in Arctic vegetation as well as changes in species composition both in the tundra and the boreal forests. Here, we leveraged solar induced chlorophyll fluorescence (SIF) to study changes in ecosystem phenology across the pan-Arctic domain from 2000 to 2020. Ecoregions, as a proxy for plants’ functional traits, were the single most important variable to explain the spatial and phenological heterogeneity in observed SIF trends. We observed unique regional trends in ecosystems responses to climate change affecting the timing of spring photosynthesis onset, magnitude of peak productivity during the growing season (GS) and fall senescence. While, Photosynthetic activity in the early GS showed increasing trends across the vast majority of the pan-Arctic, it tends to decline at the end of the season for nearly half of the land area, including parts of North America but more significantly in central Siberia. The observed changes in phenology highlight the role of biodiversity in regional climate sensitivity and emphasizes the need for better representations of sub-biomes to community level information in Arctic ecosystem process models and projections. These results also highlight the importance of phenology information in ecosystem models for better understanding of the timing and magnitude of carbon uptake in the Arctic domain with accelerated changes in climate.