Species Richness Values Research Articles

Examining Woody Plant Diversity Across Indigenous Agroforestry Practices in the Kellem Wollega Zone, Western Ethiopia

Growing woody plants on farmland not only promotes biodiversity conservation but also supports the livelihood of local communities by offering essential ecosystem services. The present study aimed to assess the woody species diversity within indigenous agroforestry practices in Kellem Wollega Zone, western Ethiopia. From Kellem Wollega, three districts: Dale Sadi, Gawo Qebe,and Sadi Canqa were purposively selected. A total of 135 plots were surveyed, with 45 plots per district across various land use classes, documenting species diversity, evenness, richness, frequency, and important value index. Fifty six (56) woody species from 29 families were counted. Fabaceae family was identified as the most dominant, comprising 7 species (12.5%), followed by Moraceae and Euphorbiaceae families, each with 4 species (7.17%). About 71.43% of species identified species were categorized as trees, while 28.57% were classified as shrubs. This finding confirmed that the indigenous home garden agroforestry exhibited the greatest diversity of woody species, while woodlots exhibited the lowest diversity. Furthermore, the results indicate significant variations in species diversity across different land use categories (p<0.001). These results underscore the contribution of indigenous agroforestry practices in enhancing biodiversity and supporting a number of woody species within their ecosystem.

Birds and mammals assemblages assessment in sub-Antarctic channels of the Kawésqar National Park and Reserve, southern Chile

Clarence Island and its inland channels are part of the Kawésqar National Park and Kawésqar National Reserve, an extensive wilderness area dominated by pristine sub-Antarctic environments and high marine biodiversity. During the summer and winter of 2020, the assemblages of birds and mammals were recorded in 10 sites, and these data, the following aspects were evaluated: 1) the sampling effort used with species accumulation curves and 2) the community structure of the assemblages with alpha and beta diversity. The total richness was 35 species of birds and 6 species of mammals, representing 17% of both groups documented for the sub-Antarctic Ecoregion of Magellan. During summer and winter, low and high values of species richness and abundance were registered, which modulated low and medium values of diversity. The moderate diversity was consistent with the beta diversity values from the Whittaker index, which on average indicates low species replacement in response to seasonal change. By considering that 20 % of the recorded species have high conservation risks, it can be concluded that this type of fauna survey contributes to improve the knowledge and dissemination of the current distribution of these species, and in future scenarios it will be useful to help predict local extinction events for anthropogenic or natural reasons.

Grime’s ecological strategies reveal contrasting patterns in alkaline and loess grasslands

Studying the relationship between biodiversity patterns and processes in vegetation has been at the centre of interest in vegetation ecology for several decades. By studying the biomass of loess and alkaline grasslands along a water and salinity gradient, we aimed to analyse species diversity and Grime’s competitor-stress tolerator-ruderal (CSR) functional strategy patterns. We aimed to test the following hypotheses: i) The biomass and species richness scores and the species composition are significantly different between the sampled grassland community types. ii) The sampled communities are well separated based on the CSR strategy spectrum. iii) The amount of green biomass and litter are positively correlated with competitiveness and negatively with stress tolerance. The biomass and species richness scores and the species composition of the sampled communities along the sampled gradients were significantly different; the highest species richness, evenness and Shannon diversity values were found in loess grasslands. The highest level of litter accumulation was found in alkaline meadows. The communities were well separated in the ordinations but surprisingly, calculation of coordinates for CSR strategy types have not shown clear separation of the grassland community types. All the communities were proven to be characterised by a high level of stress (located in the right corner of the CSR ternary diagram), but they markedly differed in the magnitude of competition and levels of disturbance expressed in the differences of ruderality. These results might suggest that even in highly stressed communities the community composition is strongly dependent on the differences in disturbance intensity (e.g., intensity and duration of grazing) and it is also strongly influenced by the competitive ability of constituting species.

Study on interspecific relationships, community stability, and environmental factors of lithophytic moss at different elevations in karst cities.

Ecosystem stability arises from the interplay of species diversity, environmental conditions, and external disturbances. Understanding the structure of plant communities, interspecific relationships, and community stability in urban ecosystems is fundamental to ecological restoration and community development. This study utilized the karst city of Guiyang as a case study and employed the α diversity index, variance ratio method (VR), χ 2-test, Pearson correlation test, Spearman rank correlation test, M. Godron stability, and canonical correspondence analysis (CCA). The research focused on analyzing the species diversity, interspecific associations, community stability, and environmental factors of lithophytic moss at various elevations (989-1398 m). The findings revealed the presence of 58 species belonging to 27 genera and 13 families of lithophytic moss in the study area. Notably, the Brachytheciaceae and Pottiaceae emerged as dominant, exhibiting a broad ecological range and adaptation mechanisms, thereby playing a crucial role in the ecological environment of rocky desertification. The study observed that the highest species richness and dominance values of lithophytic moss were recorded at the N4 (1296-1398 m) elevation gradient, while the highest species diversity and uniformity values were observed at the N3 (1194-1295 m) elevation gradient, indicating a significant impact of altitude on lithobryophyte species diversity, particularly at middle and high altitudes. The analysis of interspecific associations and stability indicated a predominantly negative overall association within the lithophytic moss community, suggesting an early stage of succession, with weak interspecific associations and correlations among dominant pairs, tending towards relative independence. Only the communities at N2 (1092-1193 m) elevation exhibited stability, while the other communities were in an unstable stage, showing no significant correlation with species diversity. Furthermore, light intensity (182-129300 lux) exerted the greatest influence on community stability. Additionally, air humidity (36.5-52.3%) and altitude (998-1327 m) emerged as the primary environmental factors influencing community distribution, with a close and positive correlation between the two. These results hold significant reference value for promoting the succession and steady development of vegetation in rocky desertification areas and enhancing the conservation and restoration of vegetation community diversity in karst urban ecosystems.

Diverse and ecologically unique mesophotic coral ecosystems in the central Indian Ocean

Research on Mesophotic Coral Ecosystems (MCEs; 30–150 m) has grown exponentially in the last few decades, highlighting their rich diversity and extensive distribution. However, they are still largely underexplored compared to shallow-water coral reefs and frequently remain under-protected and under-represented in marine spatial planning. One reason for the imbalance between the high ecological value of MCEs and the limited levels of protection may be that baseline data on MCEs are largely missing to date, yet are crucial to provide evidence-based information for management actions. Here, we present data on the alpha and beta diversity of the benthic communities within MCEs in the Chagos Archipelago, Indian Ocean. Using imagery collected from Remotely Operated Vehicle surveys, benthic invertebrate megafauna were surveyed along the entire depth gradient from shallow to lower mesophotic depths (15–160 m). The diversity of the benthic communities decreased with increasing depth, from shallow water to the lower mesophotic zone. Nevertheless, the deepest parts of MCEs in the Archipelago displayed higher species richness values than several other shallow subtropical regions. In addition, the benthic communities showed high dissimilarity along the depth gradient, indicating that the key driver of community composition change with depth is species turnover (species replacement), revealing the uniqueness of MCEs. This study presents novel findings on MCEs in the central Indian Ocean, demonstrating that they host a high and unique benthic diversity, and highlighting the need to protect these ecosystems to preserve the overall biodiversity of coral reefs.

Inter-annual changes in zooplankton in the Volga delta kultuk zone in summer (low-water period)

The paper presents the results of our studies of inter-annual changes in the structure of summer zooplankton in the kultuk zone of the Volga delta depending on hydrological and meteorological conditions. The study shows the main trends in zooplankton differences in a series of low-water years. It was found that in low-water years in the kultuk zone with low runoff, short floods and weak watering of floodplain territories, zooplankton was characterized by low species richness, reduced average individual mass of crustaceans and the number of Rotifera, but a high proportion of the number of juvenile Copepoda. In the year when the water level decreased before the flood during the period of temperature increase, and then a rapid rise with the inflow of cold waters and the removal of fish larvae, zooplankton was characterized by a minimum species richness and quantitative values of Rotifera, but increased biomass of Cladocera and the Shannon index. In every low-water year, with a stable and relatively high water level before the flood, fish spawning in the kultuk zone, biomass of zooplankton reduced due to Cladocera, and the number of species in the sample. In every mid-water year, the flood had the largest runoff and prolonged, increased flooding of the floodplain, zooplankton was characterized by the maximum total and specific species richness, abundance of Rotifera, total biomass on account of Cladocera, and the individual mass of crustaceans, the Shannon index, but the minimum proportion of juvenile Copepoda.

The Assessment of Biodiversity Changes and Sustainable Agricultural Development in The Beijing-Tianjin-Hebei Region of China

In the face of a series of challenges, such as climate change, population growth, and agricultural intensification, as well as the issue of how to promote sustainable development and guarantee food security, biodiversity, with its unique genetic, ecological, and traditional socio-cultural values, has become an important way to solve this dilemma. Urban biodiversity has continued to decline in recent decades due to rapid urbanization. The agroecosystem health of the Beijing-Tianjin-Hebei region, a typical urban agglomeration economic area, is facing a critical situation. Therefore, assessing the potential of ecosystem diversity in the Beijing-Tianjin-Hebei region and exploring the assessment mechanisms and methods of ecosystem health can provide theoretical support for biodiversity conservation and utilization. In this thesis, the overall ecosystem health of the Beijing-Tianjin-Hebei region was assessed based on the land cover data from 1992 to 2022 and the projected land cover data up to 2032, as well as using the habitat quality indicated by the Fragstats and InVEST models and the landscape pattern index, habitat quality, and mean species abundance (MSA) indicators of the GLOBIO module. The main results are as follows: Habitat quality and mean species abundance (MSA) in the Beijing-Tianjin-Hebei region were observed to show a continuous downward trend over 40 years from a landscape level perspective, and landscape fragmentation due to urbanization was the main reason. Habitat loss and habitat degradation caused by landscape fragmentation led to a decline in biodiversity. The spatial distribution of habitat quality in the Beijing-Tianjin-Hebei region is closely correlated with topography and landscape, being higher in the northwest and lower in the southeast, forming a clear spatial pattern that declined from 0.599 to 0.564 between 1992 and 2032. The mean species richness (MSA) value of the Beijing-Tianjin-Hebei region is significantly affected by infrastructure, especially road construction. With the continuous expansion of the road network, the MSA values in the region generally show a decreasing trend from 0.270 to 0.183 between 1992 and 2032. Based on the above results, it is recommended to carry out several aspects of agrobiodiversity conservation and ecosystem restoration.

Health status and characterisation of Gibraltar’s maerl beds

Maerl beds form heterogeneous, three-dimensional habitats for numerous species, housing high levels of biodiversity and species richness across the globe. Despite the importance of maerl’s ecological and carbon-regulating role; there is still a lack of information on methods to characterise its health. Therefore, this research set out to develop a standardised health assessment framework to assess the overall health of maerl a) structural function and b) habitat function. The framework was tested in an area of Gibraltar that has historically been severely impacted from various pressures including water quality. The maerl health is in a critical status, as over 92 % of it is deemed dead, with high levels of surface erosion and unusual colourations observed, and rhodoliths were generally small in size (mean: 1.35 cm ± 0.19 cm). The habitat health was labelled as intermediate, based on the species richness values, signs of nursery function, high number of Terebellidae (n = 233), distribution and coverage, and type of sediment composition. The maerl-forming species morphologically identified as Lithophyllum cf. racemus and Lithothamnion cf. corallioides were found to be present in the study site, which are first records within Gibraltar’s waters.

Mangrove Diversity as An Indicator of Ecosystem Health on Ambon Island, Indonesia

The research aims to determine the species richness, diversity and distribution of mangrove populations in forest areas, which is one of the parameters of forest health in the Passo Village’s mangrove forest. It was conducted from July to August 2023 on Ambon Island using the Forest Health Monitoring Field Methods Guide. The research covered 2 hectares of mangrove forest with 3 clusters of 12 observation plots. It was found that seven species of mangroves were found in the area, namely Sonneratia alba, Rhizophorastylosa, Avicennia marina, Aegiceras corniculatum, Bruguiera gymnorrhyza and Bruguiera parviflora. Cluster 1 had 260 trees. Cluster 2 had 321 trees, and Cluster 3 had 193 trees. The highest value of mangrove species richness was at the sapling level of 1,003. Meanwhile, the species diversity was classified as low at only 0.701 at the seedling level. The highest density of the Sonneratia alba species was 4,290, the species dominance of the Sonneratia alba was 22,240, and the highest importance index occupied by the Sonneratia alba was 160.95. Considering the low level of mangrove forest biodiversity on Ambon Island, rehabilitation and reforestation efforts are needed to maintain the quality and health of the ecosystem, especially in facing the impact of climate change on small islands.

Restoring a dry tropical forest through assisted natural regeneration: enhancing tree diversity, structure, and carbon stock

Deforestation is a key factor in global climate change, severely impacting ecosystem services. Effective implementation of reducing emissions from deforestation and forest degradation (REDD+) initiatives is essential for mitigating this change. Reforestation is a sustainable way to mitigate deforestation effects. We studied the impact of assisted natural regeneration (ANR) on restoring dry forest land, increasing biodiversity, structure, and carbon stock. Reforestation units were established at a multiple row planting system in a dry tropic region. We selected 63 plots, each 20 m × 20 m, categorized into multiple row–mixed plantation (MRMP) and multiple row–unmixed plantation (MRUP). We measured tree height and diameter at breast height (DBH) and evaluated biodiversity indices, including the Shannon–Weiner Index (SWI), species richness, evenness, and Important Value Index (IVI). Carbon stock was estimated using allometric equations. We identified 931 individual trees representing 27 species, 24 genera, and 14 families. MRMP showed significantly higher biodiversity, species richness, and evenness than MRUP. Terminalia arjuna was the most dominant species (IVI=124.45), followed by Khaya senegalensis (53.84). Survival rates exceeded 90 % for T. arjuna, K. senegalensis, Madhuca longifolia, and Pongamia pinnata (p<0.001). No significant differences were observed in tree DBH, tree height, tree density, basal area, and carbon stock among the plantation categories. The species Albizia saman exhibited a high diameter increment rate (4.07 ± 1.55 cm/year), followed by K. senegalensis (3.83 ± 0.43 cm/year). A mean value of 5.63 ± 1.13 MgC/ha of carbon stock was stored, while 20.66 ± 4.13 Mg/ha of atmospheric CO2 was sequestered. The results highlight that promoting mixed tree species in multiple rows to enhance biodiversity and optimize carbon regulation. This technique should be popularized to restore the dry forest landscape across the region.

Impacts and status of Invasion by Lantana camara in natural forests of an Indo-Burma biodiversity hotspot region- A case study in Mizoram, India

Invasion by Lantana camara represent a major threat for biodiversity and ecosystems functioning on a global scale. In this study, we investigated the ecological impact of Lantana camara invasion in natural forests of Mizoram. The sampling plots were implemented within six sites spread across the state and Lantana camara invasion were investigated along altitudinal gradient. In addition to the associated floristic inventory, we gathered the socio-economic utilization data. The results revealed that Lantana camara invasion cause adverse effects where it may result into suppression of various native plant species of invaded communities. The floristic and phytosociological assessment from Lantana camara invaded natural forests revealed a total of 74 species belonging to 68 genera and 30 families. Herbs were the dominant habit (60%) followed by shrubs (26.67%) and climbers (13.33%). The most dominant family was represented by Asteraceae with 18 species belonging to 16 genera. The general plant species diversity, density, richness and importance value index were reduced by the invasion of Lantana camara. Hence, based on the associated species present in the invaded study areas, forest management activities may be followed for the sustainable control measures to eliminate the spread of the invasive Lantana camara. This study recommends the imperative nature of effective Lantana camara management, particularly during the initial stages of invasion.

Potential distribution and ecological impacts of Acmella radicans (Jacquin) R.K. Jansen (a new Yunnan invasive species record) in China

Background Acmella radicans(Jacquin) R.K. Jansen is a new invasive species record for Yunnan Province, China. Native to Central America, it has also been recently recorded invading other parts of Asia. To prevent this weed from becoming a serious issue, an assessment of its ecological impacts and potential distribution is needed. We predicted the potential distribution of A. radicans in China using the MaxEnt model and its ecological impacts on local plant communities and soil nutrients were explored.ResultsSimulated training using model parameters produced an area under curve value of 0.974, providing a high degree of confidence in model predictions. Environmental variables with the greatest predictive power were precipitation of wettest month, isothermality, topsoil TEB (total exchangeable bases), and precipitation seasonality, with a cumulative contribution of more than 72.70% and a cumulative permutation importance of more than 69.20%. The predicted potential suitable area of A. radicans in China is concentrated in the southern region. Projected areas of A. radicans ranked as high and moderately suitable comprised 5425 and 26,338 km2, accounting for 0.06 and 0.27% of the Chinese mainland area, respectively. Over the 5 years of monitoring, the population density of A. radicans increased while at the same time the population density and importance values of most other plant species declined markedly. Community species richness, diversity, and evenness values significantly declined. Soil organic matter, total N, total P, available N, and available P concentrations decreased significantly with increasing plant cover of A. radicans, whereas pH, total K and available K increased.ConclusionOur study was the first to show that A. radicans is predicted to expand its range in China and may profoundly affect plant communities, species diversity, and the soil environment. Early warning and monitoring of A. radicans must be pursued with greater vigilance in southern China to prevent its further spread.

Insights on Evaluating Commercially Important Macroinvertebrate Species in Danjugan Island Marine Reserve, Philippines

The commercial importance of benthic macroinvertebrates like echinoderms and molluscs has led to the overexploitation of wild stocks in many areas around the Philippines. Despite their ecological and economic importance, studies on the status of wild populations of commercial macroinvertebrates in unexploited habitats such as marine protected areas (MPAs) are very scarce. The diversity and abundance of commercially valuable echinoderms and molluscs in the seagrass and reefs of Danjugan Island Marine Reserve were assessed. Shallow areas (1-3 m depth) around the island were surveyed both during the day and after dusk using belt transects. A total of 226 individuals belonging to 21 different taxa were recorded during the surveys, of which 71% were molluscs and 29% were echinoderms. In the seagrass habitat, Cypraeidae, Toxopneustidae, and Conidae were the dominant families, while molluscs from the Cardiidae family comprised more than half of the total assemblage in the reef flat. The most diverse commercial macroinvertebrate group was Holothuriidae with five different species. The densities of the families were higher during dusk than during the day in both habitats, except for Cardiidae in the seagrass. The highest values of species richness and H´ index were observed during dusk surveys in the reef habitat (H´= 1.57), while the lowest was observed in seagrass areas during morning surveys (H´= 1.37). This is the first study that assessed commercially valuable macroinvertebrates during day and night in two connected habitats within a protected area. The differences in diversity and abundance in each habitat depending on the time of day highlight the importance of considering these factors when evaluating macroinvertebrate populations in unexploited areas.

Helminth community of Nectomys squamipes naturally infected by Schistosoma mansoni in an endemic area in Brazil: A comparison of 22 years apart

The municipality of Sumidouro in the state of Rio de Janeiro, southeastern Brazil, is considered an area with low endemicity of Schistosoma mansoni. In this municipality, the wild water rat Nectomys squamipes is a wild reservoir of S. mansoni. A helminth community survey was carried out on N. squamipes populations in Sumidouro from 1997 to 1999. In the present study, we compared the helminth fauna and the helminth community structure of N. squamipes with a recent survey after a 22-year time interval, considering that the prevalence of S. mansoni infection in humans remained stable and that the area showed the same environmental characteristics. Seventy-three host specimens of N. squamipes collected between 1997 and 1999 and 21 specimens collected in 2021 were analyzed in this study. Seven helminth species were found in each collection period. The nematode Syphacia evaginata was recorded for the first time in N. squamipes in 2021. Syphacia venteli was the most abundant species in both periods and the most prevalent in 2021. During the period from 1997 to 1999, the most prevalent species was Hassalstrongylus epsilon. Significant differences in prevalence and abundance in relation to host sex were observed only for S. mansoni in 1997–1999. Significant differences in the abundance of the helminth species over time were observed only in Physaloptera bispiculata. Hassalstrongylus epsilon, S. venteli and S. mansoni were the dominant species in both periods. Litomosoides chagasfilhoi, Echinostoma paraensei paraensei and P. bispiculata became dominant, codominant and subordinate, respectively, over time. In conclusion, the helminth community of N. squamipes remained stable, with similar species richness, prevalence and abundance values and low beta-diversity over time. The occurrence of S. mansoni in the water rat has remained stable for decades, highlighting its importance for schistosomiasis control.

Red‐deer dung increases species diversity but does not influence species composition of open grasslands

AbstractQuestionsFree‐ranging herbivores are often seen as important endozoochorous dispersal vectors for plant propagules. Dispersal by free‐ranging animals, in contrast to domestic animals, and its effects on vegetation have rarely been studied. We ask what are the effects of deposition of dung on open landscape vegetation, how does it influence vegetation development after disturbance by soil removal, and does it change species richness or composition?LocationThe Doupov Mountains, Czech Republic.MethodsWe established a six‐year experiment in 2015 to study the effects of dung deposition on vegetation of an open grassland landscape. The experiment comprised 300 plots distributed across five fenced site locations and treatments were implemented in partially crossed design, with soil removed (disturbance) and dung pellets deposited; treatments were applied once to five replicates, from June to October 2015. We recorded plant species cover at the beginning of the vegetation seasons of 2016, 2017 and 2021.ResultsDung deposition increased species richness and Ellenberg Indicator Values for nutrients, and these effects were stronger in disturbed plots; however, these effects diminished with time. There were no effects of dung deposition on species composition. In contrast, disturbance affected species diversity, composition, Ellenberg Indicator Values for nutrients, proportion of dung‐dispersed species, but not species richness. Surprisingly, there were no effects of timing of dung deposition.ConclusionsOur results indicate that endozoochorous seed dispersal by red deer impacts vegetation dynamics of this open grassland landscape, but effects are weak and diminish with time. Considering the large seed load in dung, it is possible that endozoochorous seeds from wild herbivores are incorporated into the soil seed bank, where they persist until appropriate ecological conditions for germination arise.

Tropical gastropod density and diversity in the mangrove forest of Totobo Village, Southeast Sulawesi, Indonesia

Abstract. Purnama MF, Prayitno SB, Muskananfola MR, Suryanti. 2024. Tropical gastropod density and diversity in the mangrove forest of Totobo Village, Southeast Sulawesi, Indonesia. Biodiversitas 25: 1663-1675. The mangrove ecosystem of Totobo Village, Southeast Sulawesi, is a habitat for various species of edible and economically important gastropods. This research aims to determine mangrove gastropods' density and ecological index (diversity). This research was carried out from June to September 2023 in the mangrove ecosystem of Totobo. This research adopts purposive sampling and systematic random sampling techniques to determine stations and place the distribution of sampling points (sub-stations). The gastropod sample collection was done using the handpicking method or manually. More than 34 species of gastropods (14 families and 24 genera) were found in the mangrove ecosystem of Totobo. The diversity index (H' = 3.07) of gastropods in the Totobo mangrove ecosystem is directly proportional to the species richness value (R = 4.43), which is in the high category. The evenness index is in the medium category (E = 0.89), and the dominance index (C) has a value of 0.01, meaning no dominance of a particular species. The condition described is a representation of a system of homeostasis or environmental balance that is currently being maintained. This directly impacts the optimal biological activity (physiology) of the gastropod community and other aquatic organisms in the mangrove ecosystem (estuary) of Totobo Village.

The southernmost Errina antarctica hydrocoral savannah in Patagonian waters

Marine animal forest (MAF) are animal-dominated megabenthic communities that support high biodiversity levels and play key roles in ecosystem functioning. However, there is limited data available in Patagonian waters related to the presence of these vulnerable benthic communities. We report a monospecific MAF of Errina antartica in Angostura Tomms, which represents the southernmost known living MAF of this species. With coverages reaching up to 28.5% of the substrate from 1.23 m to, at least, 33 m depth is the shallowest stylasterid assemblage described worldwide to date. The size of the colonies ranged from 0.14 to 15.8 cm, with small colonies (< 10 cm) being the most abundant (99%). We hypothesize that this MAF might correspond to a recent colonization of a space, extending its distribution range towards shallower areas or it could be an assemblage formed at the limit of the species’ distribution in which the environmental conditions are not optimal for the major development of the colonies. Additionally, results showed that habitats structured by three-dimensional sessile invertebrate such as E. antarctica showed higher values of species richness and alpha diversity than non-biogenic habitats. Analyses were based on 297 photos taken at 22 different sites in the western Strait of Magellan, along vertical transects from 5 to 25 m depth. Our study highlights the importance of the benthic communities existing in Patagonian waters, evidencing the need to act actively to ensure their maintenance.

Long-term changes in water quality and structure of benthic animal communities in the Neva estuary under anthropogenic stress

In the Neva River estuary, 188 species and taxa of a higher rank of benthic animals were found, of which 129 were found in the eastern part of the Gulf of Finland. At present, the zoobenthos of the estuary is dominated by eurybiont species inhabiting polluted waters. We used integrated index IP' specially devised for water-bodies and rivers of the north-western Russia to assess the water quality and a state of ecosystems of the Neva estuary. It is based on structural parameters of zoobenthic communities and makes it possible to take into consideration the pollution by toxic and organic substances. On average the water quality of the Neva Bay assessed from IP′ values was relatively stable during 1994–2021. It was assessed as “polluted” with the exception of 2006 and 2015 caused by large-scale dredging works. In the period 1982–2021, the average number of zoobenthos species at one station in the Neva Bay almost doubled, from 12 ± 1 species in 1982 to 23±2 species in 2020. In the resort area of the eastern Gulf of Finland, the values of species richness and the Shannon index were much lower than in the Neva Bay, and on average for one station varied from 5±0.6 to 14±4 species and from 1.1±0.2 to 2.3±0.2 bit/ind. This is caused by the influence of salinity, eutrophication and pollution, and invasion of alien species. In addition to intense anthropogenic impact, the dynamics of the state of zoobenthos in this part of the estuary was determined by climate fluctuations.

Biodiversity and productivity in eastern US forests

Despite experimental and observational studies demonstrating that biodiversity enhances primary productivity, the best metric for predicting productivity at broad geographic extents-functional trait diversity, phylogenetic diversity, or species richness-remains unknown. Using >1.8 million tree measurements from across eastern US forests, we quantified relationships among functional trait diversity, phylogenetic diversity, species richness, and productivity. Surprisingly, functional trait and phylogenetic diversity explained little variation in productivity that could not be explained by tree species richness. This result was consistent across the entire eastern United States, within ecoprovinces, and within data subsets that controlled for biomass or stand age. Metrics of functional trait and phylogenetic diversity that were independent of species richness were negatively correlated with productivity. This last result suggests that processes that determine species sorting and packing are likely important for the relationships between productivity and biodiversity. This result also demonstrates the potential confusion that can arise when interdependencies among different diversity metrics are ignored. Our findings show the value of species richness as a predictive tool and highlight gaps in knowledge about linkages between functional diversity and ecosystem functioning.

Agriculturally Improved and Semi-Natural Permanent Grasslands Provide Complementary Ecosystem Services in Swedish Boreal Landscapes

Permanent grasslands cover more than a third of European agricultural land and are important for a number of ecosystem services. Permanent grasslands used for agriculture are broadly separated into agriculturally improved and semi-natural grasslands. High cultural and natural values linked to semi-natural grasslands are well documented. However, in boreal and hemi-boreal agricultural landscapes, less information is available about the areal coverage of improved permanent grasslands and their role for ecosystem service provision and biodiversity. In Sweden, grasslands are administratively separated into semi-natural (i.e., land that cannot be ploughed) or arable (i.e., improved temporary or permanent grassland on land that can be ploughed). We used data from a large-scale environmental monitoring program to show that improved permanent grassland (i.e., permanent grasslands on arable fields) may be a previously unrecognised large area of the agricultural land use in Sweden. We show that improved permanent grasslands together with semi-natural grasslands are both comparable but also complementary providers of a range of ecosystem services (plant species richness, plant resources for pollinators and forage amount for livestock production). However, as expected, semi-natural grasslands with the highest-level AESs (special values) show high species richness values for vascular plants, plants indicating traditional semi-natural management conditions and red-listed species. Improved permanent grasslands on arable fields are likely an underestimated but integral part of the agricultural economy and ecological function in boreal landscapes that together with high nature value semi-natural grasslands provide a broad range of ecosystem services.