Habitat protection for sensitive species: Balancing species requirements and human constraints using bioindicators as examples

Vertebrates have particular habitat needs as a function of life cycle and reproductive stage. This paper uses four species as examples to illustrate a paradigm of environmental assessment that includes physical, biological, toxicological and human dimensions. Species used include Chinook salmon (Oncorhynchus tshawytscha), northern leopard frog (Rana pipiens), northern pine snake (Pituophis m. melanoleucus), and red knot (Calidris canutus rufa, a sandpiper). The life cycles of these species include reliance on habitats that are aquatic, terrestrial, aerial, or combinations of these. Two species (frog, snake) are sedentary and two (salmon, sandpiper) are long-distance migrants. While some measurement endpoints are similar for all species (reproductive success, longevity, contaminant loads), others vary depending upon life cycle and habitat. Salmon have a restricted breeding habitat requiring coarse sand, moderate current, and high oxygen levels for adequate egg incubation. Leopard frogs require still water of appropriate temperature for development of eggs. Pine snakes require sand compaction sufficient to sustain a nest burrow without collapsing, and full sun penetration to the sand to allow their eggs in underground nests to incubate and hatch. Red knots migrate to high Arctic tundra, but incubate their own eggs, so temperature is less of a constraint, but feedinging habitat is. These habitat differences suggest the measurement endpoints that are essential to assess habitat suitability and to manage habitats to achieve stable and sustainable populations. Habitat use and population stability have implications for human activities for some, but not all species. Salmon are important economically, recreationally, and as part of Native American culture and diet. Red knots are of interest to people mainly because of their long, intercontinental migrations and declining populations. Other measurement endpoints for these four species illustrate the differences and similarities in metrics necessary to assess habitat needs. The implications of these differences are discussed.

Role of the Zinc Nutritional Status on Main Physiological Bioindicators of the Pecan Tree

The purpose of this study was to analyze the effect of Zn nutritional status on the content of pigments, nonstructural carbohydrates, foliage proteins and amino acids of the pecan tree, as possible bioindicators of Zn deficiency. The experimental design was completely random with three Zn nutritional statuses: Normal, Intermediate and Deficient, being selected considering visual symptomatology. On all three nutritional statuses, the concentration of photosynthetic pigments was determined as well as of total soluble proteins and amino acids. Obtained results indicate that Zn deficient nutritional status was characterized by minimum photosynthetic pigment, protein concentrations, maximum amino acid and nonstructural carbohydrate concentrations. While the normal Zn nutritional status presented maximum photosynthetic pigments, proteins concentrations, minimum amino acids and carbohydrate concentrations. On the other hand, intermediate Zn nutritional status was characterized by a medium level between the other two Zn nutritional statuses. Finally, we stress the fact that pigments, proteins, amino acids and nonstructural carbohydrates may be good physiological indicators related to Zn nutritional status on pecan trees.

Determining Environmental Impacts for Sensitive Species: Using Iconic Species as Bioindicators for Management and Policy

Environmental assessment of impacts, management, and policy are important aspects of protection of human health and the environment. Assessing the impacts of human activities requires selection of bioindicator species that can be used to assess, manage, and develop public policies that ensure ecosystem integrity, and therefore sustainability of social, cultural, and economic systems. With the use of Chinook Salmon (Oncorhynchus tshawytscha), Pacific Cod (Gadusmacrocephalus), Mallard (Anas platyrhynchos), and Red Knot (Calidris canutus rufa), we explore assessment and measurement endpoints, and their relationship to management and development of public policy. This combination of fish and birds provides a diversity of life histories, ecosystem roles, human values, and resource use to explore their use as bioindicators and endpoints. It also allows examination of 1) conservation and protection of species and biodiversity, 2) protection of ecosystems, 3) provision of goods and services, and 4) societal well-being.

Meiobenthos Assemblages as Bioindicators for Coastal Pollution Assessment

Coastal pollution assessment is a pressing matter as the anthropogenic pressure continues to increase worldwide. A leading approach to assess coastal pollution is using bioindicators. However, identifying species is time-consuming and demands profound morphological knowledge. Our goal was to find the meiobenthic composition in each pollution level. By utilizing the meiobenthic assemblage’s ratios, we will be able to indicate the pollution level. We examined the meiobenthos distribution at three sites exposed to a pollution gradient. We quantified the changes in the fauna assemblage in the community phylum level, focusing on nematodes and foraminifera (90% of the total population). Over 400 samples were examined, covering an annual seasonal cycle. Nematodes population dominated in the polluted coast. Nematodes density increased with the pollution level, up to seemingly harmful levels of pollution. In contradiction, the foraminifera flourished in the control site and exhibited an inverse relationship to the nematodes. We witnessed drastic changes in the entire meiobenthic population in the winter, which we speculate that originated from winter turbulences. We suggest that nematodes-foraminifers’ population ratios may be utilized as bioindicators for assessing coast intertidal zone pollution levels.

Inventory and Distribution of Benthic Macroinvertebrates, Indicators of Water Quality in Four Forested Watercourses in Centre Region of Cameroon

The inventory of benthic macroinvertebrate species was carried out in some streams of the Mefou catchment area, from August 2021 to August 2022, in order to determine the biological groups that make up the population and characterise these environments. The dataset acquired during this study made it possible to update the existing database and contribute to the knowledge of the biological groups associated in these environments, and to provide additional information on the existing ones in relation to bioindication. Overall 80 families were identified and, on the basis of frequencies of occurrence greater than 75%, 22 families were retained as potential biological indicators. The remarkable diversity of insects and the low abundance of Diptera reflect the low degradation of environments and the good quality of water. The high diversity indices obtained reflect the maintenance of the favourable ecological conditions that favours the development of a balanced and, integrated biological community capable of adapting to changes.

Air Quality Assessment of Ubeji Community near Petroleum-Related Activities

The escalating global concern over air pollution requires rigorous investigations. This study assesses air quality near residential areas affected by petroleum-related activities in Ubeji Community, utilizing Aeroqual handheld mobile multi-gas monitors and air quality multi-meters. Air sampling occurred on three distinct days using multi-gas monitors and meters, covering parameters such as CO, NO2, CH4, NH3, VOCs, Particulate Matter, Temperature, Relative Humidity, and Air Quality Index. Soil and plant samples were collected and analyzed for physicochemical and organic components. Air pollutant concentrations showed significant fluctuations. Carbon monoxide (CO) ranged from 0.00 to 3.22 ppm, NO2 from 0.00 to 0.10 ppm, CH4 from 4.00 to 2083 ppm, NH3 from 371 to 5086 ppm, and VOCs from 414 to 6135 ppm. Soil analysis revealed low total nitrogen, and undetected BTEX levels. Plant samples displayed a pH range of 7.72 to 9.45. CO concentrations, although below WHO limits, indicated potential vehicular and industrial influences. Fluctuations in NO2 and CH4 were linked to traffic, industrial activities, and gas flaring. NH3 levels suggested diverse pollution sources. The result in this study highlights the dynamic nature of air pollution in Ubeji community, emphasizing the urgent need for effective pollution control measures. Although CO concentrations were within limits, continuous monitoring is essential. Elevated NO2 levels gave information on the impact of industrial activities, while high CH4 concentrations may be associated with gas flaring and illegal refining. The study recommends comprehensive measures and collaborative efforts to address these complex issues, safeguarding both the environment and public health. This study shows the potential synergy between air quality sensors and plants for holistic environmental health assessments, offering valuable insights for environmental assessments and remediation endeavours. The findings call for stringent regulations and collaborative efforts to address air pollution in Ubeji community comprehensively.

A summary of Copepoda:synthesis,trends,and ecological impacts

Copepoda are one of the most significant animal groups present in aquatic ecosystems.Ecologists,evolutionary biologists,and biotechnologists continue to test new methods to study the application of Copepoda as model organisms in various fields of pure and applied science,from evolution and ecology to aquaculture as live feed,as biological control of mosquito larvae,as biological indicators of water and sediment quality,in environmental monitoring and as a source of protein in the food industry.This paper reviews the current progress and trends within copepod research from a number of different perspectives.We emphasize the importance of Copepoda and the necessity of strengthening research on various topics related to copepod biology,some of which are of great significance to local sustainable development.

Macroinvertebrates as Bio Indicators of Water Quality in Pinyinyi River, Arusha Tanzania

Rivers are important for aquatic biodiversity. Anthropogenic activities degrade rivers and decrease their capacity to offer ecosystem services. This study used macroinvertebrates to assess the impact of anthropogenic activities on the Pinyinyi River during dry and wet season. Abundance of macroinvertebrates, average score per taxon and Shannon Weiner Species Diversity Index were used to state the ecological status of Pinyinyi River. Because the abundance of macroinvertebrates can be affected by change in water quality, some of the physicochemical parameters were also measured. A macroinvertebrates hand net is used to collect the macroinvertebrates per sampling point. DO, temperature, pH, turbidity and TDS were measured in-situ using HI-9829 Multiparameter and BOD was measured in the laboratory using Oxydirect levibond method. A total of 164 macroinvertebrates were collected and identified from Pinyinyi River during dry and wet season. They belong to 13 families. The most abundant taxa were mosquito larva, Diptera (41.07%) and aquatic caterpillar, Lepidoptera (23.21%) during dry season representing about 64.28% of the total macroinvertebrates whereas the least abundant taxa were pouch snail (16.07%) and dragonflies, Odonata (19.64%) during dry season representing about 35.72% of the total macroinvertebrates. The most abundant taxa collected during wet season were aquatic earthworm, haplotaxida (19.44%), midges, Diptera (17.59%), black flies, Diptera (15.74%) and creeping water bugs, hemiptera (12.96%) whereas the least abundant were pigmy back swimmers, hemiptera (2.78%), snail (3.7%), predacious dividing beetle (4.63%) and coleopteran (4.63%). Average Score per taxon of Pinyinyi River during dry season was 5.25 and 3.6 during wet season. The Shannon Weiner Species Diversity Index was 1.318 during dry season and 2.138 during wet season. Based on the score, Pinyinyi River is moderately polluted during dry season and seriously polluted during wet season. Based on index, Pinyinyi River has low diversity of macroinvertebrates during dry season and highly in diversity of macroinvertebrates during wet season. Moreover, it was found that, agricultural activities, livestock keeping, bathing and washing alter physicochemical parameters of Pinyinyi River and hence change the abundance of macroinvertebrates as well as the quality of water. The study, therefore, recommends that the source of pollutants should be controlled and the river regularly monitored by the relevant authorities.

Artificial Night Lighting Reduces Firefly (Coleoptera: Lampyridae) Occurrence in Sorocaba, Brazil

Artificial night lighting is gaining attention as a new type of pollution;however, studies of its impacts are scarce. Fireflies provide good models to investigate its effects on nocturnal wildlife, since they depend on their bioluminescence for reproduction. This study investigated the impact of artificial illumination on firefly activity at the new campus of the Federal University of S&atildeo Carlos (Sorocaba, Brazil). The flashing activity of different firefly species, especially Photinus sp1 (82% of all occurrences), was investigated during 3 years, before and after the installation of multi metal vapor spotlights. Quantitative and qualitative analysis, performed in transects at different distances from the artificial light sources, showed significant negative effects on Photinus sp1 occurrence. This study proposes fireflies as potential flagship species and bioindicators for artificial night lighting and for the first time quantifies its effects, providing subsidies for future conservationist legislations regarding photopollution.

Preliminary Assessment of Anthropogenic Impact on Some Ecological Components of Abesan River, Lagos, Nigeria

The impact of anthropogenic disturbances on water quality parameters, diversity of macrophytes and benthic macro fauna of Abesan River, Lagos, Nigeria is reported. Some Physico-chemical and biological assessment were carried out at three sampling stations located at downstream (AR-1), midstream (AR-2) and upstream (AR-3) with different levels of disturbance. Results of measured physico-chemical parameters showed that there was no significant difference (P > 0.05) in temperature, total acidity and chloride values between the sampling stations. Although, Total solids, conductivity, DO, Sulphate, BOD and COD were significantly higher (P < 0.05) at Stn.AR-1 than at Stns. AR-2 and AR-3, all physico-chemical parameters measured were within the limits of the Lagos State Environmental Protection Agency (LASEPA) and the World Health Organization (WHO) regulatory standards except for high COD concentration in downstream station. Aquatic vegetation (macrophyte) diversity was relatively abundant at upstream and downstream stations, suggesting possible impact of human activities on macrophyte diversity at midstream station where highest level of disturbance occurred. Chironomid larvae were the most abundant invertebrate fauna found in all three sampling stations but more abundant at sampling station AR-2 which corresponds to point of effluent entry to river where human activities is most intense. There is evidence that anthropogenic activities impact on the water quality of Abesan River. Biotic indices such as Sorensenen’s Index of Similarity and Margalef Index show that Abesan River is lightly polluted. The implications of these results and the need to monitor the water quality of Abesan River are highlighted.

Responses of <i>Marsilea minuta</i>L. to Cadmium Stress and Assessment of Some Oxidative Biomarkers

In a hydroponic based experiment, the Cd toxicity is monitored with some cellular responses of Marsilea plant. Initially, plants were grown under varying concentrations (0, 50, 100 and 200 μM of Cd) of cadmium (Cd) with supplementation of 2 mM spermidine (Spd). The oxidative stress developed by Cd overaccumulation was measured with fall in Relative Growth Rate (RGR) by 27.11% to 59.83% growth reduction over control under varying Cd treatments. The retrieval of RGR was recovered by 1.59 folds as compared to the highest concentration of Cd (200 μM) when plants were fed with Spd. A concomitant degradation of chlorophyll was recorded in dose-dependant manner, however, the retrieval was not much pronounced with Spd. On the contrary, the non-oxidant thiol had borne more clarity with ongoing Cd concentration and appeared to be 40.51% increase maximally for GSH: GSSG at the highest concentration of Cd. Spd has minimized the ratio by 27.4%. The recovery of osmotic turgidity was indexed with a sharp rise in glycine betaine by 3.86 folds maximum at the highest concentration of Cd over control which declined by 30.9% with Spd. Another cellular response of treated plants was more evident from their isozymic profiles with regard to superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX). The intensity of protein expression was significantly variable but not in band numbers as evident from Cd treated plants. In vitro enzyme assay of catalase showed as declining trend within the limit of 33.13% to 43.22% which was reported by 1.45 folds when Spd was applied. Therefore, from the present study, the cellular responses of Marsilea plant which showed compatibility for their expression with Cd toxicity could be hypothesized as a case of bioindication.

The Saproxylic Activity Index: A New Tool for the Rapid Assessment of Deadwood Species during Forest Restoration

Restoring deadwood habitat is vital in order to recreate fully functioning forest ecosystems. Letting this process occur naturally can take in excess of one hundred years, thus management practises typically try to accelerate this via the artificial addition of deadwood. Since the species which rely on deadwood often have poor dispersal abilities, restoring deadwood habitat rarely results in the full restoration of the saproxylic fauna. Furthermore, standard deadwood monitoring protocol only records the amount and type of substrate available and is not capable of determining whether saproxylic insects have been restored. Full species inventories are time-consuming, costly and require great expertise. We present a rapid biodiversity assessment tool which we believe is the first protocol for measuring saproxylic activity which is accessible to non-specialists. Utilising the exit bore holes which saproxylics create on deadwood can provide an indication of the density, richness and diversity of species present;we call this the Saproxylic Activity Index. We show that this index can detect differences in the activity of insects between substrates. As saproxylic insects provide important ecosystem functions, such as aiding in the decay of deadwood and recycling nutrients, a measure of their activity levels may indicate the rate of restoration of these ecosystem processes. We believe that further exploration of this method provides an exciting opportunity for the functional restoration of saproxylic fauna to become incorporated into mainstream forest management.

Floral Species as Environmental Quality Indicators in Jordan: High Salinity and Alkalinity Environments

In this study the occurrence and ecology of plant assemblages are investigated, mainly for use as indicator plants of saline grounds in several locations in Jordan. High alkalinity and H2S-rich water tolerant species of plants are also discussed. Plants growing on salty grounds have distinct composition regarding their place in the taxonomic system. Plant assemblages and their degree of tolerance to salinity as in Karama area in the Jordan Valley are found to be distinct from that of Azraq Sabkha (Cental Jordan) with salt-tolerant flora. Karama area provides the living space for Mesembryanthemum on the saltiest ground, Suaeda further up on wetter surrounding and Salicornia succeeding on moist and less salty grounds. Drier places with rather salty grounds have bushes of Arthrocnemum, while slightly less salty places are preferred by Tamarix tetragyna. When Prosopis bushes appear, salt is only present periodically in the ground, as is also the case with Atriplex halimus and Capparis. In Azraq the former beach of a temporal lake is characterized by two species of Spergularia in its saltier parts and by Tamarix passerinoides. It was recognized that Tamarix, Phragmites, Chenopodium, and Inula represented alkaline water tolerant plants. The study concludes that the salt concentration in the ground is reflected in the composition of the flora growing on it. On the other hand, plants are also found vulnerable to fluctuation in the salt concentration of their environments with different resistance degrees. This makes them excellent bioindicators of salty environments.

Nematodes for Soil Quality Monitoring: Results from the RMQS BioDiv Programme

A French programme, “Réseau de mesure de la qualité des sols: biodiversité des organismes” (RMQS BioDiv) was developed in Brittany (27,000 km2 in the western part of France) as an initial assessment of soil biodiversity on a regional scale in relation to land use and pedoclimatic parameters. The nematode community assemblages were compared among the land use categories. Crops were characterised by a high abundance of bacterial-feeders, particularly opportunistic bacterial-feeders belonging to Rhabditidae. Meadows presented a higher total abundance of nematodes than did crops (20.6 ind·g-1 dry soil vs. 13.1 ind·g-1 dry soil), and they were mainly linked to the great abundance of plant-parasitic nematodes, particularly Meloidogyne, but with a very high heterogeneity between sampled plots. The nematodes were most abundant in forests (23.7 ind·g-1 dry soil) and presented the most structured community (SI = 82.2 in forests vs. 58.6 and 55.5 in crops and meadows, respectively). Forests had also the higher fungal component (fungal-feeders and facultative plant-feeders belonging to the Tylenchidae) leading to a significant higher part of the fungal decomposition pathway in forests than in crops. The ability of different taxonomic levels of nematode identifica- tion to discriminate among different cropping systems (i.e., continuous cropping system, crop with meadow in the rota- tion, meadow with crop in the rotation and permanent meadow) was also tested. The family level (48 families identified in these samples) was more efficient than the other taxonomic levels (86 taxa, 17 functional guilds and 6 trophic groups): best statistical significant discrimination for time spent in identification. The relation between the nematode ecological indices, the abundance of nematode trophic groups and the crop management practices were studied. The effects of fertilization, ploughing frequency, use of pesticides and management systems on ecological indices, particu- larly on the Maturity Indices, were observed.

Is maturity index an efficient tool to assess the effects of the physical disturbance on the marine nematode assemblages?—A critical interpretation of disturbance-induced maturity successions in some study cases in Maldives

Maturity index（MI）, based on nematode life strategies, has been proposed in 1990 to assess the possible variations of the terrestrial and freshwater nematode assemblages induced by anthropogenic activities. It was subsequently applied also to marine ecosystems and, even if comparatively not yet very popular, it offers a good method to assess the ecological quality in relation to a wide range of anthropogenic drivers. However, few data are available on its response to physical stress, a key factor especially in the coastal areas. In this study, marine nematode genera from two study cases carried out in Maldives are used to test both MI and life strategy traits（i.e.,c-p classes） for detecting the effects of physical disturbance. The results confirm that nematodes are well adapted to physical stress showing a general high rate of recovery. C-p scaling and MI did not seem to be appropriate for revealing this disturbance type probably because there are no empirical evidences on the life strategy of several genera, and a possible differential response to various disturbance types may be hypothesized.

Soil Seed Banks in Two Environments of Forest Restoration Post Bauxite Mining:Native Tree Plantation and Natural Regeneration

The objective of this study was to compare the soil seed bank in an area under natural regeneration(F1)and another reforested through seedling planting(F2),seven years after bauxite mining,in Southeast,Brazil.In each area,10 sampling points were randomly distributed,using three samples of topsoil to represent each point.The samples were transported to a shade house and evaluated for six months,where emerging individuals were identified every two weeks.Floristic similarity was evaluated with cluster analysis based on the Jaccard index(SJ).Species richness and abundance of individuals were compared using Student's t test.In F1,2,114.94 propagules m-2 were registered,belonging to 51 species and 24 botanical families,Shannon-Wiener diversity index H’=2.770 and Pielou evenness index J’=0.705.In F2,1,168.62 propagules m-2 were registered,belonging to 42 species and 22 families,H’=2.618 and J’=0.700.The(SJ)between F1 and F2 was 0.61,indicating a high similarity.The results showed high density of propagules,good diversity and absence of ecological dominance.The high number of individuals and diversity of tree species with zoochoric dispersion found in the areas indicates that both natural regeneration and reforestation were efficient in the ecological restoration of bauxite mined areas.

Determination of Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAH) Contents Using the Lichen<i>Dirinaria picta </i>in Universiti Kebangsaan Malaysia

A biomonitoring study on lichens was conducted to assess the levels of atmospheric heavy metal and polycyclic aromatic hydrocarbon (PAH) at ten sites at the Universiti Kebangsaan Malaysia Campus, Bangi, Selangor, Malaysia. Dirinaria picta, epiphytic lichen which commonly found at lowland areas was used as the bioindicator in this study where samples were collected from the bark of palm trees at sites ranging from areas with high volume of traffic to isolated areas in the campus. Eight metals (Cr, Fe, Co, Ni, Cu, Zn , Al, Pb), and ten PAH;naphthalene (PAH1), acenaphtylene (PAH2), acenaphthene (PAH3), fluorine (PAH4), anthracene (PAH5), phenanthrene (PAH6), fluoranthene (PAH7), pyrene (PAH8), benzo (b) anthracene (PAH9) and chrysene (PAH10) were analyzed in the naturally growing thallus of Dirinaria picta. The average concentration of the metals was observed to be in the range of 230.6 ppm (Fe) to 0.3 ppm (Co) and for PAH, it was observed in the range of 612 ppm (PAH1) to 79.5 ppm (PAH10). The One-way ANOVA analysis for both the heavy metals and the PAHs showed Ho was rejected. There are significant differences in heavy metals and PAHs concentrations between sites. The selectivity sequence of heavy metals were Fe > Cr > Ni > Al > Zn > Pb > Cu. Meanwhile for PAH, the sequence is PAH1 > PAH3 > PAH2 > PAH6 > PAH5 > PAH7 > PAH4 > PAH8 > PAH9 > PAH10.

Knowledge to Ecological Preferences in a Tropical Epiphytic Algae to Use with Eutrophication Indicators

In Ayapel floodplain periphyton associated to macrophyte roots on the basis of material was collected in fourteen sampling sites in nine moments of compilation. From the analysis of the samples were recorded 550 algal species, of which 56% were diatoms. Furthermore it was valued relative abundances of taxa and the average physicochemical variables to identify the optimal values and tolerance ranges of species. In the case of nitrates optimal value was below 2 mg/L for all algae except for Actinella sp. and Euastrum sinuosum which optimal values were close to zero with low variability. Regarding all species the algal nitrite concentration showed optimum values below 2 mg/L except Encyonema minutum and E. sinuosum whose optimum were 0.4 and 0.5 mg/L respectively. About nitrogen as ammonia was repeated the above situation, i.e. optimum values below 2 mg/L except for E. minutum and E. sinuosum. Respect to phosphorus the species with optimum greater than 0.6 mg/L are the diatoms, in contrast, the lowest values were optimal for E. sinuosum and Actinella sp. From the viewpoint of bioindication high abundance of Synedra goulardii indicates high transparency, Ulnaria ulna and Planothidium lanceolatum indicate lower concentration of dissolved oxygen and water temperature between 29°C - 30°C, Actinella aff. robusta, E. minutum, Cylindrospermopsis raciborski, Lyngbya cf. limnetica, Eunotia naegueli, Navicula cryptocephala, Diadesmis confervaceae, Frustulia rhomboides and Aulacoseira granulata.(For more information,please refer to the PDF.)

Drivers of coastal bacterioplankton community diversity and structure along a nutrient gradient in the East China Sea

Anthropogenic nutrient discharge poses widespread threats to coastal ecosystems and has increased environmental gradients from coast to sea. Bacterioplankton play crucial roles in coastal biogeochemical cycling, and a variety of factors af fect bacterial community diversity and structure. We used 16 S r RNA gene pyrosequencing to investigate the spatial variation in bacterial community composition(BCC) across five sites on a coast-of fshore gradient in the East China Sea. Overall, bacterial alpha-diversity did not diff er across sites, except that richness and phylogenetic diversity were lower in the of fshore sites, and the highest alpha-diversity was found in the most landward site, with Chl-abeing the main factor. BCCs generally clustered into coastal and of fshore groups. Chl-a explained 12.3% of the variation in BCCs, more than that explained by either the physicochemical(5.7%) or spatial(8.5%) variables. Nutrients(particularly nitrate and phosphate), along with phytoplankton abundance, were more important than other physicochemical factors, co-explaining 20.0% of the variation in BCCs. Additionally, a series of discriminant families(primarily affiliated with Gammaproteobacteria and Alphaproteobacteria), whose relative abundances correlated with Chl-a, DIN, and phosphate concentrations, were identified, implying their potential to indicate phytoplankton blooms and nutrient enrichment in this marine ecosystem. This study provides insight into bacterioplankton response patterns along a coast-of fshore gradient, with phytoplankton abundance increasing in the of fshore sites. Time-series sampling across multiple transects should be performed to determine the seasonal and spatial patterns in bacterial diversity and community structure along this gradient.

Responses of terrestrial bryophytes to simulated climate change in a secondary evergreen broad-leaved forest in southern China

Tropical regions are biodiversity hotspots and are well-suited to explore the potential influence of global climate change on forest ecosystems. Bryophytes have essential ecological functions in tropical forest ecosystems, but knowledge of the potential impact of global warming and possible changes in water availability patterns on terrestrial bryophytes is limited. We transplanted eight terres- trial moss species from two elevations (900 and 500 m) to warmer and drier elevations (500 and 100 m) during a halfyear observation period on Tai Mo Shan, southern China. The simulated climate change resulted in severely declined health status and marked decrease in growth of the trans- planted species when compared with their performance at the original elevations. Five of the eight selected species survived for six months after being transplanted to the warmer and drier lowlands, though their health status deteriorated severely. Sematophyllum subhumile , Pseudotaxiphyllum pohliaecarpum and Brachythecium buchananii were highly susceptible to changes in temperature and rainfall patterns and might be used as suitable bioindicators. As the tropics are expected to become hotter and drier, terrestrial mosses might be negatively affected or even be at risk of extinction. Bryophytes in the tropics could represent one of the best biological communities to reflect the direct adverse impact of climate change and provide early warning of the biological outcomes induced by ongoing climate crisis.