Ecological Monitoring Studies Research Articles

Potential impacts of cable bacteria activity on hard-shelled benthic foraminifera: implications for their interpretation as bioindicators or paleoproxies

Abstract. Hard-shelled foraminifera are protists able to build a calcareous or agglutinated shell (called a “test”). Here we study the impact of sediment acidification on calcareous test preservation. For this study, sediment cores were sampled in the macrotidal Auray estuary located on the French Atlantic coast. Living and dead foraminifera were quantified until 5 cm depth and discriminated using the Cell-Tracker™ Green vital marker. The pH and oxygen profiles combined with quantitative polymerase chain reaction (qPCR) suggested that cable bacteria were most likely to cause the acidifying process. Cable bacteria (CB) are filamentous bacteria coupling sulfide oxidation to oxygen reduction over centimetre distances, generating a strong pH gradient within the first few centimetres of the sediment that could affect the microhabitats occupied by benthic foraminifera. On two different intertidal mudflats, volumetric filament densities have been estimated. They were comparable to those observed in the literature for coastal environments, with 7.4 ± 0.4 and 74.4 ± 5.0 m cm−3 per bulk sediment, respectively. Highly contrasting sediment acidification (from low to very intense) was described from 1.0 to 2.4 ΔpH. This seems to lead to various dissolution stages of the foraminiferal calcareous test from intact to fully dissolved tests revealing the organic lining. The dissolution scale is based on observations of living Ammonia spp. and Haynesina germanica specimens under a scanning electronic microscope. Furthermore, dead foraminiferal assemblages showed a strong calcareous test loss and an organic lining accumulation throughout depth under low pH, hampering the test preservation in deep sediment. These changes in both living and dead foraminiferal assemblages suggest that cable bacteria must be considered in ecological monitoring and historical studies using foraminifera as bioindicators and paleoenvironmental proxies.

A Recommended Monitoring Tool for the marine ecological status studies in the Western Moroccan Mediterranean coastal areas

This research provides general guidelines for monitoring the environmental quality state of the marine ecosystems using benthic microfauna as a bioindicator tool in the Western Moroccan Mediterranean coastal areas. The current faunistic composition of 18 superficial sediment samples collected in areas having a wild range of environmental conditions have been the subject of factorial correspondence and hierarchical classification analysis, allowing us to follow the distribution patterns of the benthic assemblages. Considering the influence of both hydrodynamic and sedimental conditions on the superficial sediment, recognized in this study as the main environmental factors affecting the distribution of species in this type of environment, we were able to delineate three environmental units, with specific faunistic response related to the corresponding environmental conditions. Leading us to identify the optimal sampling area for the biomonitoring surveys in this region. Shallow and high-energy coastal areas were found to limit data collection and the representation of the sampling area, while low-energy areas were identified as ideal for environmental surveys, showcasing strong faunistic response to stressful conditions. we recommend to conduct the ecological monitoring studies in the 10–30-meter depth range, where the environmental conditions favor the assessment of the current environmental quality state by the benthic microfauna.

A Machine Learning Perspective on Daisy and Dandelion Classification: Gaussian Naive Bayes with Sobel

This study explores the classification of Daisy and Dandelion flowers using a Gaussian Naive Bayes classifier, enhanced by Sobel segmentation and Hu moment feature extraction. The research adopted a quantitative approach, utilizing a balanced dataset of Daisy and Dandelion images. The Sobel operator was employed for image segmentation, accentuating the floral features crucial for classification. Hu moments, known for their invariance to image transformations, were extracted as features. The Gaussian Naive Bayes algorithm was then applied, with its performance evaluated through a 5-fold cross-validation process. The results exhibited moderate accuracy, with the highest recorded at 60%, and precision peaking at 62.60%. These findings indicate a reasonable level of effectiveness in distinguishing between the two species, though variations in performance metrics suggested room for improvement. The study contributes to the field of botanical image classification by demonstrating the potential of integrating image processing techniques with machine learning for flower classification. However, it also highlights the limitations of the Gaussian Naive Bayes approach in handling complex image data. Future research directions include exploring more advanced machine learning algorithms and expanding the feature set to enhance classification accuracy. The practical implications of this research extend to ecological monitoring and agricultural studies, where efficient and accurate plant classification is vital

Multi-Scale Validation and Uncertainty Analysis of GEOV3 and MuSyQ FVC Products: A Case Study of an Alpine Grassland Ecosystem

Fractional vegetation cover (FVC) products provide essential data support for ecological environmental monitoring and simulation studies. However, the lack of validation efforts of FVC products limits their applications. Based on Sentinel-2 data and intensive multi-scale measured FVC data, the accuracies of two FVC products (GEOV3 and MuSyQ) in alpine grassland ecosystems were validated through direct validation and multi-scale validation. Based on the heterogeneity of the underlying surface (HUS) of the monitoring plots, the impact of the HUS of the monitoring plots on the product validation was analyzed. The results showed that: (1) the measured data directly validated that the GEOV3 FVC product performed better than the MuSyQ FVC product; (2) the multi-scale validation method based on high-resolution reference FVC map of Sentienl-2 satellite images validated the accuracy of these two FVC products, which was higher than the accuracy directly validated by FVC measured data, leading to overestimation of the validation results; and (3) the HUS of the monitored plots has a significant impact on the FVC product validation. By quantifying the HUS of the monitored plots and removing the heterogeneous monitoring plots, the uncertainty of the validation results can be reduced. It is necessary to consider the impact of validation methods and the HUS on the validation results in future product validation.

Ecological Monitoring and Omics: A Comprehensive Comparison of Workflows for Mass Spectrometry-Based Quantitative Proteomics of Fish (Labeo rohita) Liver Tissue.

Introduction: The liver is highly sensitive to the environmental factors. Liver tissue, particularly from fish, is often used as a biological target in ecological monitoring, disease research, and stress response studies. Labeo rohita (rohu) is a fish with a significant role in the global aquaculture economy. Methods: Bottom-up proteomics relies on efficient sample preparation for performing mass spectrometric analysis of the liver tissue. Optimization of protein solubilization and digestion strategies is the key step to obtain reliable data for a successful proteomics experiment. Because the goal of extraction is to acquire the optimum protein quality and yield, the first step should be to choose an appropriate extraction method based on the type of sample. Solubilization buffers containing sodium dodecyl sulfate (SDS) or urea, and digestion methods such as filter-aided sample preparation (FASP), suspension trap (S-Trap) and in-solution are often used in proteomics but are in need of comparative evaluation with an eye to protocol optimization. Experiment: We applied two different solubilization buffers (one containing SDS, and other containing urea) and three digestion methods (FASP, S-Trap, and in-solution) to the proteomic analysis of the fish (L. rohita) liver tissue. Label-free quantification analysis was performed to analyze the similarities and differences in the results with each method. Gene ontology-based functional analysis was performed for the identified proteome across the experimental conditions to overview their protein classes, molecular functions, and biological processes. Results: SDS lysis followed by S-Trap digestion outperformed the other combinations of lysis and digestion in terms of higher protein coverage, consistency in the results and repeatability. Filter-based methods provided comparatively better results than in-solution digestion. Discussion: This protocol presents new insights on ways to optimize discovery and targeted proteomic analyses of liver tissue using the fish L. rohita as a case study. Other tissues can also be evaluated in the future drawing from the results in this study. This would help the scientific community with hypothesis-driven studies on topics ranging from basic biology to applied aquaculture research and ecological monitoring. This is particularly relevant in the current era of ecological crises and environmental pollution, where advances and optimization in research protocols can contribute to in-depth studies of ecosystems and planetary health.

ЭКОЛОГО–ГЕОХИМИЧЕСКАЯ ОЦЕНКА СОДЕРЖАНИЯ НЕФТЯНЫХ УГЛЕВОДОРОДОВ В ПОЧВАХ ТАЕЖНОЙ ЗОНЫ НИЖНЕГО ПРИАМУРЬЯ И СЕВЕРНОГО САХАЛИНА (ДАЛЬНИЙ ВОСТОК)

The background content of total petroleum hydrocarbons (TPH) in the most common soils of the Lower Amur region and Northern Sakhalin was determined. About 300 samples taken from the surface layers and horizons of 8 typical soil pedons were analyzed. The accumulative nature of TPH distribution in the soil profile was established, and their highest content was revealed in the organogenic horizons. The soils of eluvial landscapes (Podzols, Spodic Cambisols, Fulvic Cambisols) contain a smaller amount of TPH compared to the soils of accumulative landscapes (Histosols, Fluvisols). The maximum content of TPH was found in the Spodic Hyperalbic Technosols. The content of TPH in the anthropogenic abrasives of the Lower Amur region is estimated as acceptable, the level of pollution in the anthropogenic abrasives in Northern Sakhalin varies from low to very high. The results obtained on the background content of TPH can used for assessing of soils pollution and in conducting ecological monitoring studies.

Retrieval of Land Surface Temperature With Topographic Effect Correction From Landsat 8 Thermal Infrared Data in Mountainous Areas

Accurate estimation of land surface temperature (LST) is crucial for ecological environment monitoring and climate change studies in mountainous areas. The current LST retrieval algorithms were developed without accounting for the topographic effect, which can only be used to retrieve LST over relatively flat surfaces. Due to the impact of 3-D structure of mountainous surfaces, rugged terrain makes the processes of thermal radiation more complex. In this study, a radiative transfer equation (RTE)-based single-channel algorithm was proposed to retrieve LST with topographic effect correction from the Landsat 8 thermal infrared (TIR) data in mountainous areas. This algorithm accounts for the changes in the thermal radiation components in the TIR RTE caused by the topographic effect. According to the analysis of simulation data, sky-view factor (SVF), atmospheric water vapor content, surface emissivity of target pixel, and average LST of the surrounding terrain have significant influence on the magnitude of the topographic effect. The differences between the LST retrieved without/with topographic effect correction from the Landsat 8 TIR data are related to SVF. The topographic effect should be taken into account in the LST retrieval algorithm when SVF is smaller than 0.7. The largest LST difference of approximately 1 K occurs in the deep valley. The results indicate that LST without topographic effect correction could be overestimated to be as high as 1 K. Due to a lack of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> LST measurements, the performance of the LST retrieval algorithm in mountainous areas was only evaluated by comparing the brightness temperature (BT) at the top of the atmosphere (TOA) simulated by the DART+MODTRAN model and the TIR RTE over mountainous surfaces at three subregions. There is a good consistency between BT at the TOA simulated by the DART+MODTRAN model and the TIR RTE over mountainous surfaces at the three subregions, with a root-mean-squared error (RMSE) of less than 0.23 K.

If you build it, they will come: Restoration positively influences free-living and parasite diversity in a restored tidal marsh

Ecological monitoring studies have shown that surrogate species can provide good predictive power for the community diversity of other taxa. In our study, we sampled for resident and transient fauna in several newly created oyster reefs. We also sampled for common multi-host parasites in these organisms, as parasite abundance can act as a surrogate for trophic complexity in structured habitat. The restoration consisted of three treatments: control plots (no restoration), stacked bags of oyster shell, and reefs constructed from a novel design made of concrete and burlap. We also included three previously restored loose-shell reefs for comparison. Over 16 months, we quantified parasite diversity in mudsnails, crustaceans, and benthic fishes, as well as crustacean and fish free-living diversity. Taxa richness increased post-restoration for most free-living and parasite groups, regardless of restoration design, and communities shifted toward reef-resident species assemblages. Shell bags showed the greatest positive change in richness one-year post-restoration—at 2× that of control plots on average. The relative abundance of trematodes also increased with time, particularly those using fish as final hosts, and nematodes, cestodes, and entoniscid isopods were also more abundant post-restoration. Habitat complexity and abiotic factors (e.g., temperature and dissolved oxygen) were also positively correlated with shifts in host and parasite diversity. Our study demonstrates that free-living and parasite responses to restoration can occur rapidly and are sensitive to restoration design and site-specific environmental characteristics. Parasites are thus a promising tool for quantifying biodiversity and ecosystem health, particularly in systems subject to frequent monitoring.

Monitoring for the abundance and distribution of phytoplankton along the hypersaline Bardawil Lagoon, in Northern Sinai, Egypt (Multivariate Analysis Approach)

Bardawil Lagoon is a source of wildlife and high-quality fish, so, it is imperative that it should be subject to continuous monitoring of both water quality and the phytoplankton composition. Samples were collected from ten sites representing different habitats of the lagoon, from summer 2017 to spring 2018. The water properties were determined; noticeable low concentrations of dissolved inorganic nutrients were recorded. A total of 106 species belonging to six groups were recorded, among them Bacillariophyta (69 species) and Dinophyta (26 species). The obtained results clarify that Bacillariophytes prevailed in the eastern sites of Bardawil; on the contrary, Dinophytes occupied the sovereignty in the western sites of the lagoon. The most abundant Bacillariophytes were Licmophora gracilis, Gyrosigma acuminatum, Fragilaria construens, and Nitzschia sigmoidea; which formed more than 50% of total abounded diatoms. While, Protoperidinium leonis, Prorocentrum gracile and Protoperidinium granii were the dominant Dinophytes, giving it maximum at El-Rewak. From reviewing previous studies on the lagoon, it becomes clear that the phytoplankton composition varied widely from previously recorded, including the dominant species and their rates of sovereignty, which reflected economically on its fish productivity. Besides, the water quality in Bardawil fluctuated from slightly-polluted to moderately-polluted according to the diversity index, as a result of the recent, noticeable increase in human activities, especially fishing, which will be in turn reflected in the environment. Therefore, continuous follow-up through ecological assessment and monitoring studies of Bardawil became an urgent necessity.

Changes in abundance of fish-parasitic gnathiid isopods associated with warm-water bleaching events on the northern Great Barrier Reef

Mass coral bleaching events due to rising seawater temperatures are occurring with increasing frequency and are among the most conspicuous consequences of human-induced climate change. While bleaching events have clear impacts on the corals themselves, the impacts on other organisms and on the overall reef community are more difficult to assess. This is particularly true for parasitic organisms, which in spite of their high diversity and biomass are typically ignored in ecological monitoring studies. Here, we take advantage of long-term monitoring of host–parasite–cleaner interactions on experimental patch reefs to assess the effects of mass bleaching events on gnathiid isopod populations around Lizard Island, Great Barrier Reef. Compared with non-bleaching years, gnathiid abundance was consistently low during the warm-water period in bleaching years, but rebounded during the cooler months. This pattern is likely due to the interaction between the short-term negative impacts of thermal stress and declines in hosts on gnathiids, combined with the longer-term positive impacts of declines in cleaner wrasses and of increased dead coral on gnathiid abundance.

Are litterfall and litter decomposition processes indicators of forest regeneration in the neotropics? Insights from a case study in the Brazilian Amazon

Litterfall plays an important role in nutrient cycling and maintenance of soil fertility in terrestrial ecosystems. We gauged the effects of anthropogenic impacts on the production, decomposition and seasonality of litterfall in primary and secondary forests within a tropical landscape of the Brazilian Amazon. We hypothesized that leaf litter quantity and quality would differ in line with forest disturbance and that these changes would translate into dissimilar decomposition rates. If proved, these processes could be used as surrogates for indentifying the ecological status of forest habitats. The obtained results have shown that, in the study area litterfall is reduced and litter decomposition is braked in disturbed habitats when compared with primary and recovered secondary forests. Also, within similar climatic conditions, the litter production and decomposition rates begin to stabilize in mature secondary forests. Our results represent a useful contribution to understand the dynamics of the litterfall and litter decomposition processes in the neotropics. Both processes were correlated and sensitive to disturbance gradients and should used as forest recovery indicators in ecological monitoring and ecological restoration studies.

Climate Change in Remote Mountain Regions: A Throughfall-Exclusion Experiment to Simulate Monsoon Failure in the Himalayas

The Himalayas are predicted to experience more than 3 times the mean global rise in temperature, as well as erratic rainfall patterns and an increased likelihood of total monsoon failures. While many ecosystem manipulation experiments aiming at understanding the effects of altered precipitation, temperature, and carbon dioxide are conducted globally, such experiments are rare in Asia, particularly in the Himalayas. To fill this gap, we simulated late onset of monsoon precipitation, as well as total monsoon failure, in a multiyear drought stress experiment in Bhutan. Two treatments, 100% throughfall exclusion and ambient control plots, were applied to 725 m2 plots (25 m × 29 m), each with 2 replicates in a hemlock-dominated (Tsuga dumosa) and oak-dominated (Quercus lanata and Quercus griffithii) ecosystem at 3260 and 2460 m elevations, respectively. Roof application reduced the volumetric soil water content in the upper (0–20 cm) soil layer by ∼ 20% in coniferous and ∼ 31% in broadleaved forest; the deeper soil layers were less affected. We demonstrate that large-scale throughfall-exclusion experiments can be successfully conducted even in a remote Bhutan Himalayan setting. The experiences gathered could be utilized for future long-term ecological monitoring studies in the Himalayan region.

Image subsampling and point scoring approaches for large-scale marine benthic monitoring programs

Benthic imagery is an effective tool for quantitative description of ecologically and economically important benthic habitats and biota. The recent development of autonomous underwater vehicles (AUVs) allows surveying of spatial scales that were previously unfeasible. However, an AUV collects a large number of images, the scoring of which is time and labour intensive. There is a need to optimise the way that subsamples of imagery are chosen and scored to gain meaningful inferences for ecological monitoring studies. We examine the trade-off between the number of images selected within transects and the number of random points scored within images on the percent cover of target biota, the typical output of such monitoring programs. We also investigate the efficacy of various image selection approaches, such as systematic or random, on the bias and precision of cover estimates. We use simulated biotas that have varying size, abundance and distributional patterns. We find that a relatively small sampling effort is required to minimise bias. An increased precision for groups that are likely to be the focus of monitoring programs is best gained through increasing the number of images sampled rather than the number of points scored within images. For rare species, sampling using point count approaches is unlikely to provide sufficient precision, and alternative sampling approaches may need to be employed. The approach by which images are selected (simple random sampling, regularly spaced etc.) had no discernible effect on mean and variance estimates, regardless of the distributional pattern of biota. Field validation of our findings is provided through Monte Carlo resampling analysis of a previously scored benthic survey from temperate waters. We show that point count sampling approaches are capable of providing relatively precise cover estimates for candidate groups that are not overly rare. The amount of sampling required, in terms of both the number of images and number of points, varies with the abundance, size and distributional pattern of target biota. Therefore, we advocate either the incorporation of prior knowledge or the use of baseline surveys to establish key properties of intended target biota in the initial stages of monitoring programs.

Evaluating the regional cumulative impact of wind farms on birds: how can spatially explicit dynamic modelling improve impact assessments and monitoring?

Summary The Eurasian skylark Alauda arvensis is very susceptible to the negative effects of wind farms. In northern Portugal, this evidence is particularly severe due to the skylark's preference for mountain breeding habitats where most wind farms are located. Facing the frequent failure of environmental impact assessments (EIA) to evaluate the cumulative impacts of wind farms on wildlife, this study aimed to develop and test a methodology to quantify local and regional consequences on birds, using skylarks as a test species, taking into account future predictable environmental changes. We propose a spatially explicit dynamic approach that combines the results from multiple modelling techniques under a common framework to assess the local and cumulative regional impacts of wind farms on skylark populations. This includes the following: (i) modelling the local impact of wind farms (in terms of collision mortality) on the skylark population dynamics by developing an index for quantitative assessments, (ii) determining the actual and future skylark breeding distribution across northern Portugal and (iii) integrating the above contributions in an emergent spatially explicit regional representation to capture the ecological cumulative consequences as a whole. The simulations show an increasing average local impact for the skylark breeding populations directly affected by wind farms, expressed in mean number of collision fatalities per UTM study unit (1 km2), representing 1·3% of the local breeders in 2006 and 4% in 2026. The distribution area of skylark breeding populations was predicted to decrease around 4·5% throughout a period of 15 years, as a result of the scenario of climate and land cover changes in the study area. When combined with a concomitant increase in skylark global mortality (c. 184%) induced by all wind farms in the study region, the above trend contributes to an intensification of the regional cumulative impact from 1·2% to 3·7% of the total estimated breeding individuals. Synthesis and applications. The proposed modelling framework represents a step forward in evaluating the multi‐scale cumulative consequences of wind farms on vulnerable birds, using skylarks as a test species. This could be used in the future to guide monitoring efforts and to improve the applicability of the data bases generated by long‐term ecological research and monitoring studies.

Bayesian binomial mixture models for estimating abundance in ecological monitoring studies

Investigation of species abundance has become a vital component of many ecological monitoring studies. The primary objective of these studies is to understand how specific species are distributed across the study domain, as well as quantification of the sampling efficiency for detecting these species. To achieve these goals, preselected locations are sampled during scheduled visits, in which the number of species observed at each location is recorded. This results in spatially referenced replicated count data that are often unbalanced in structure and exhibit overdispersion. Motivated by the Baltimore Ecosystem Study, we propose Bayesian hierarchical binomial mixture models, including Binomial Conway-Maxwell Poisson (Bin-CMP) mixture models, that formally account for varying levels of spatial dispersion. Our proposed models also allow for variable selection of model covariates and grouping of dispersion parameters through the implementation of reversible jump Markov chain Monte Carlo methodology. Finally, using demographic covariates from the American Community Survey, we demonstrate the effectiveness of our approach through estimation of abundance for the American Robin (Turdus migratorius) in the Baltimore Ecosystem Study.

Bee and wasp responses to a fragmented landscape in southern Brazil

The available studies on Hymenoptera assemblages in fragmented landscapes have shown that these insects are sensitive to fragmentation, besides some different conclusions which are possibly linked to different landscape attributes and sampling designs. The present objective is to determine the correlation among the descriptors of bees and wasps assemblages with fragment predictors (size, connectivity and edge effect) within a fragmented landscape of Semidecidual Seasonal Forest (Parana State, Brazil). For this purpose five forest fragments, from three to 484 hectares, were sampled during a year, summing up 480 samples of baited traps and 3,480 of bowl traps. We have found that abundance of Apinae and oligolectic bees increase and the richness of Augochlorini bees decreases with increasing fragment size. Connectivity has positively influenced bee richness and edge effect has positively influenced the abundance of oligoletic bees. Orchid bees also respond to the site predictors, especially for the Eufriesea violacea, which abundance was positively correlated with fragment size and connectivity, however negatively with edge effect, and Eufriesea nigrita which abundance was negatively correlated with fragment size, but positively with edge effect. Composition of bees, Crabronidae and Pompilidae wasps were influenced by fragment size. Plebeia droryana and Tetrapedia diversipes could be considered as indicators, according to their sensitiveness to habitat predictors. Our results are congruent with previous studies which found that bees are sensitive to landscape fragmentation, we suggest that the group be used in ecological indicator and monitoring studies.

Bioaccumulation of cadmium and lead and its effects on hepatopancreas morphology in three terrestrial isopod crustacean species

This study was designed to compare cadmium (Cd) and lead (Pb) bioaccumulation in three species of oniscidean isopods – Armadillidium granulatum Brandt, Armadillidium vulgare (Latreille) and Porcellio laevis Latreille which were exposed for three weeks to a contaminated diet, and to determine the morphological and ultrastructural changes in hepatopancreas. Metal accumulation, determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), was linearly associated with the exposed concentration and was a function of the metal and the species tested. All three species accumulated lower levels of Pb than Cd. A. vulgare accumulated the largest concentration of Pb, especially at the higher doses, whereas P. laevis showed the greatest Cd accumulation, and the highest Cd concentration was lethal for all exposed species. The highest concentrations of Pb and Cd induced significant changes both in the general morphology of tubules and in the ultrastructural organization of epithelial cells in hepatopancreas. Some Pb/Cd induced alterations include: brush border disorganization; reduction of the basal labyrinth formed by the plasma membrane; condensation of some cytoplasm areas and of chromatin; rough endoplasmic reticulum and mitochondrial alterations; increase of secondary lysosomes and of type B granules in S cells. Some of the ultrastructural changes observed overlap with those induced by prolonged starvation, whereas others can be useful biomarkers of heavy metal toxicity. This study has confirmed that in terrestrial isopods, the accumulation of the different metals occurs in a species-specific manner; therefore ecological monitoring and assessment studies should consider each species individually. The research has confirmed that in the terrestrial isopods the accumulation of the different metals occurs in a species-specific way; therefore each species should first be evaluated in view of its employ in biomonitoring programs.

Consequence of altered nitrogen cycles in the coupled human and ecological system under changing climate: The need for long-term and site-based research.

Anthropogenically derived nitrogen (N) has a central role in global environmental changes, including climate change, biodiversity loss, air pollution, greenhouse gas emission, water pollution, as well as food production and human health. Current understanding of the biogeochemical processes that govern the N cycle in coupled human-ecological systems around the globe is drawn largely from the long-term ecological monitoring and experimental studies. Here, we review spatial and temporal patterns and trends in reactive N emissions, and the interactions between N and other important elements that dictate their delivery from terrestrial to aquatic ecosystems, and the impacts of N on biodiversity and human society. Integrated international and long-term collaborative studies covering research gaps will reduce uncertainties and promote further understanding of the nitrogen cycle in various ecosystems.

Detecting a population decline of woodland caribou (Rangifer tarandus caribou) from non‐standardized monitoring data in Pukaskwa National Park, Ontario

ABSTRACTObservation bias from methodological inconsistencies plague many long‐term ecological monitoring studies, leaving land managers to question the validity of apparent population trends over time. Furthermore, some species are cryptic and have low detectability, so assessments are naturally imprecise. We assessed the utility of aerial surveys for woodland caribou from 1972 to 2009 at a Canadian national park in detecting a reliable population trend for this threatened species. The surveys varied in flight patterns, total distance flown, observer experience, speed, altitude, timing, temperature, and snow depth. Of these, distance and the speed/altitude index influenced the population estimates, whereas no variables influenced the calf:female ratio or winter range size. Year was included in all plausible models for population estimates, and the majority of plausible models for calf:female ratio and winter range size. Population size, recruitment and winter range size all declined over time in the respective models with the lowest AICc. Switching methodologies mid‐way through a long‐term aerial survey monitoring program creates greater complexity for trend analysis over time; however, this study suggests that reliable conclusions can still be drawn from long‐term monitoring data if confounding factors are accounted for in the analysis. © 2014 The Wildlife Society.

Using Conceptual Models to Understand Ecosystem Function and Impacts of Human Activities in Tropical Peat-swamp Forests

Increased resource investment in conservation is generating greater appreciation of the importance of ecolog- ical monitoring programmes to assess the effectiveness of conservation interventions in achieving their stated goals. A key component for developing such a programme is an appropriate conceptual model of ecosystem function and the effects of human activities on this. Tropical peat- swamp forests are a particularly important ecosystem for reducing carbon emissions and biodiversity conservation. This is leading to increased investment in their protection and, consequently, an increased need for effective ecological monitoring programmes and conceptual models of ecosys- tem function on which to base these. Here, I adapt previous conceptual models of ecosystem function developed for terrestrial forests and other wetland ecosystems, to create a habitat-specific model for tropical peat-swamp forests. This provides a tool to guide thinking in developing ecological monitoring studies in this habitat and understanding (i) ecosystem processes and function, (ii) the impact of human activities on these, and (iii) subsequent impacts on ecosys- tem services. This is relevant for monitoring the effective- ness of conservation interventions with varying goals in tropical peat-swamp forest, including emission reductions; and highlights considerations relevant for conservation management and ecological monitoring in other wetland habitats.