scholarly journals Covariation in population trends and demography reveals targets for conservation action

2021 ◽  
Vol 288 (1946) ◽  
pp. 20202955
Author(s):  
Catriona A. Morrison ◽  
Simon J. Butler ◽  
Robert A. Robinson ◽  
Jacquie A. Clark ◽  
Juan Arizaga ◽  
...  
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
Local Population ◽  
Survival Rates ◽  
Population Trends ◽  
Population Declines ◽  
Conservation Action ◽  
Local Conditions ◽  
Widespread Species ◽  
Wide Range

Wildlife conservation policies directed at common and widespread, but declining, species are difficult to design and implement effectively, as multiple environmental changes are likely to contribute to population declines. Conservation actions ultimately aim to influence demographic rates, but targeting actions towards feasible improvements in these is challenging in widespread species with ranges that encompass a wide range of environmental conditions. Across Europe, sharp declines in the abundance of migratory landbirds have driven international calls for action, but actions that could feasibly contribute to population recovery have yet to be identified. Targeted actions to improve conditions on poor-quality sites could be an effective approach, but only if local conditions consistently influence local demography and hence population trends. Using long-term measures of abundance and demography of breeding birds at survey sites across Europe, we show that co-occurring species with differing migration behaviours have similar directions of local population trends and magnitudes of productivity, but not survival rates. Targeted actions to boost local productivity within Europe, alongside large-scale (non-targeted) environmental protection across non-breeding ranges, could therefore help address the urgent need to halt migrant landbird declines. Such demographic routes to recovery are likely to be increasingly needed to address global wildlife declines.

scholarly journals New kid on the block: Research of alpine-lake macroinvertebrates in the Tatra Mountains enhanced by DNA barcoding and metabarcoding

2021 ◽  
Vol 4 ◽  
Author(s):  
Ondrej Vargovčík ◽  
Zuzana Čiamporová-Zaťovičová ◽  
Fedor Čiampor Jr
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
Human Impacts ◽  
Sampling Error ◽  
Alpine Lakes ◽  
Alpine Lake ◽  
Tatra Mountains ◽  
Aquatic Communities ◽  
Wide Range ◽  
The Tatra Mountains

State of ecosystems and biodiversity protection are becoming the key interests for modern society due to climate change and negative human impacts (Leese 2018). Environmental changes in freshwaters are indicated also by benthic communities, especially in sensitive ecosystems like alpine lakes (Fjellheim 2009). Moreover, remoteness and isolation of alpine lakes make them a source of biodiversity, which is worth conserving (Hamerlík 2014). A promising tool for efficient large-scale monitoring of aquatic communities is DNA metabarcoding (Leese 2018). In this study, we applied metabarcoding to analyse macrozoobenthos of 12 lakes in the Tatra Mountains, using benthic bulk samples and eDNA filtered from water (Fig. 1). In compliance with recent publications, eDNA amplified with BF3/BR2 primers resulted in high percentage of non-invertebrate reads (Leese 2021). Based on in silico tests with the obtained sequences, we confirm that the recently developed EPTDr2n primer enables minimizing non-target amplification even with eDNA filtered from alpine-lake water (Elbrecht and Leese 2017). This ability is facilitated by 3’ end of the primer and we observed the two important mismatches in non-target sequences from our study (Leese 2021). Thus, our future analyses of eDNA (and bulk-sample fixative) will benefit from the new primer. Concerning bulk samples, a wide range of invertebrate taxa was assigned to the OTUs and they showed good congruence with previous studies using morphological determination (e.g. Krno 2006). Certain differences with (and among) the previous records per lake were observed, which could suggest ecological changes, but at the moment the influence of sampling error cannot be excluded. In eDNA, several taxa were congruent with the previous records, but their amount and read abundance was considerably lower due to non-target amplification. Apart from that, filling gaps in barcoding databases remains one of our priorities, as identification to species or genus level was not yet possible for some invertebrate OTUs. In addition, we subjected the NGS data to denoising and abundance-filtering in order to explore haplotype-level diversity (Andújar 2021). Although more comprehensive conclusions will be possible only after obtaining data from more lakes and years, already the two metabarcoding experiments presented here enabled us to efficiently detect within-species genetic diversity and identify a large variety of taxa, including groups that would otherwise be omitted or very challenging to identify. This underlines the potential of DNA methods to provide valuable ecological and biodiversity data across the tree of life for modern biomonitoring. This study was realized with support from VEGA 2/0030/17 and VEGA 2/0084/21.

scholarly journals Xylem anatomy needs to change, so that conductivity can stay the same: xylem adjustments across elevation and latitude in Nothofagus pumilio

2020 ◽  
Vol 125 (7) ◽  
pp. 1101-1112
Author(s):  
Ana I García-Cervigón ◽  
Alex Fajardo ◽  
Cristina Caetano-Sánchez ◽  
J Julio Camarero ◽  
José Miguel Olano
Keyword(s):  
Hydraulic Conductivity ◽  
Individual Variation ◽  
Environmental Changes ◽  
Vessel Diameter ◽  
Vessel Density ◽  
Nothofagus Pumilio ◽  
Widespread Species ◽  
Climatic Fluctuations ◽  
Wide Range ◽  
Diameter Distributions

Abstract Background and Aims Plants have the potential to adjust the configuration of their hydraulic system to maintain its function across spatial and temporal gradients. Species with wide environmental niches provide an ideal framework to assess intraspecific xylem adjustments to contrasting climates. We aimed to assess how xylem structure in the widespread species Nothofagus pumilio varies across combined gradients of temperature and moisture, and to what extent within-individual variation contributes to population responses across environmental gradients. Methods We characterized xylem configuration in branches of N. pumilio trees at five sites across an 18° latitudinal gradient in the Chilean Andes, sampling at four elevations per site. We measured vessel area, vessel density and the degree of vessel grouping. We also obtained vessel diameter distributions and estimated the xylem-specific hydraulic conductivity. Xylem traits were studied in the last five growth rings to account for within-individual variation. Key Results Xylem traits responded to changes in temperature and moisture, but also to their combination. Reductions in vessel diameter and increases in vessel density suggested increased safety levels with lower temperatures at higher elevation. Vessel grouping also increased under cold and dry conditions, but changes in vessel diameter distributions across the elevational gradient were site-specific. Interestingly, the estimated xylem-specific hydraulic conductivity remained constant across elevation and latitude, and an overwhelming proportion of the variance of xylem traits was due to within-individual responses to year-to-year climatic fluctuations, rather than to site conditions. Conclusions Despite conspicuous adjustments, xylem traits were coordinated to maintain a constant hydraulic function under a wide range of conditions. This, combined with the within-individual capacity for responding to year-to-year climatic variations, may have the potential to increase forest resilience against future environmental changes.

scholarly journals Common species link global ecosystems to climate change

2016 ◽  
Author(s):  
Bjarte Hannisdal ◽  
Kristian A. Haaga ◽  
Trond Reitan ◽  
David Diego ◽  
Lee Hsiang Liow
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
Planktonic Foraminifera ◽  
Species Abundance ◽  
Direct Interaction ◽  
Deep Ocean ◽  
Common Species ◽  
Global Changes ◽  
Ecosystem Structure ◽  
Widespread Species

Common species shape the world around us, and changes in their commonness signify large-scale shifts in ecosystem structure and function. Dominant taxa drive productivity and biogeochemical cycling, in direct interaction with abiotic components of the Earth system. However, our understanding of the dynamic response of ecosystems to global environmental changes in the past is limited by our ability to robustly estimate fossil taxonomic richness, and by our neglect of the importance of common species. To rectify this, we use observations of the most common and widespread species to track global changes in their distribution in the deep geological past. Our simple approach is robust to factors that bias richness estimators, including widely used sampling-standardization methods, which we show are highly sensitive to variability in the species-abundance distribution. Causal analyses of common species frequency in the deep-sea sedimentary record detect a lagged response in the ecological prominence of planktonic foraminifera to oceanographic changes captured by deep-ocean temperature records over the last 65 million years, encompassing one of Earth's major climate transitions. Our results demonstrate that common species can act as tracers of a past global ecosystem and its response to physical changes in Earth's dynamic history.

Large-scale variation in life history traits of the widespread diadromous fish, Galaxias maculatus, reflects geographic differences in local environmental conditions

2011 ◽  
Vol 62 (7) ◽  
pp. 790 ◽  
Author(s):  
Nicole C. Barbee ◽  
Robin Hale ◽  
John Morrongiello ◽  
Andy Hicks ◽  
David Semmens ◽  
...  
Keyword(s):  
Life History ◽  
South America ◽  
Environmental Conditions ◽  
Life Histories ◽  
Large Scale ◽  
Life History Traits ◽  
Spatial Scales ◽  
Local Conditions ◽  
Widespread Species ◽  
Galaxias Maculatus

Applying uniform population models and management strategies to widespread species can be ineffective if populations exhibit variable life histories in response to local conditions. Galaxias maculatus, one of the world’s most widely distributed fish species, occurs in a broad range of habitats and is highly adaptable, making it an ideal species for examining variation in life history traits across large geographic scales. Here, we examine the spawning biology and early life history of diadromous G. maculatus in coastal rivers in Victoria, Australia, and compare them to other populations throughout its range. We predicted that traits associated with these critical life stages, especially those that respond to environmental conditions that vary geographically, such as seasonal cues and temperature, are likely to vary across large spatial scales. We found that spawning occurs later in Victoria than in New Zealand (NZ) and South America, but migration back to rivers occurs at the same time in Victoria and NZ, but not South America. G. maculatus returning to rivers are also smaller and younger in Victoria than those in NZ. Other traits, like some attributes of spawning schools and spawning habitats, did not vary across large scales. Researchers and managers should be cautious when making broad assumptions about the biology of widely distributed species.

scholarly journals Survival Rates of Cassin's and Rhinoceros Auklets at Triangle Island, British Columbia

The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 155-162 ◽  
Author(s):  
Douglas F. Bertram ◽  
Ian L. Jones ◽  
Evan G. Cooch ◽  
Hugh A. Knechtel ◽  
Fred Cooke
Keyword(s):  
Large Scale ◽  
North Pacific Ocean ◽  
Survival Rates ◽  
Adult Survival ◽  
Population Declines ◽  
The North ◽  
Cassin's Auklet ◽  
Cerorhinca Monocerata ◽  
Ptychoramphus Aleuticus ◽  
Rhinoceros Auklet

Abstract We estimated survival of Cassin's Auklet (Ptychoramphus aleuticus) and Rhinoceros Auklet (Cerorhinca monocerata) from recapture rates during 1994–1997. For both species, a two “age”-class model provided the best fit. Estimates of local adult survival were significantly lower for Cassin's Auklet (0.672 ± 0.047) than for Rhinoceros Auklet (0.829 ± 0.095). Our estimate of survival appears lower than that required for the maintenance of a stable population of Cassin's Auklets. The available information indicates that a low survival rate and a declining population at Triangle Island are plausible, particularly given the recent large scale oceanographic changes which have occurred in the North Pacific Ocean. Nevertheless, additional mark-recapture data and indexes of population size are required to rigorously demonstrate population declines at the world's largest Cassin's Auklet colony.

scholarly journals Colony size-frequency distributions among different populations of the scleractinan coral Siderastrea stellata in Southwestern Atlantic: implications for life history patterns

2006 ◽  
Vol 54 (4) ◽  
pp. 213-223 ◽  
Author(s):  
Monica Moraes Lins de Barros ◽  
Débora de Oliveira Pires
Keyword(s):  
Life History ◽  
Colony Size ◽  
Large Scale ◽  
Environmental Changes ◽  
Size Structure ◽  
Growth Potential ◽  
Local Conditions ◽  
Frequency Distributions ◽  
Size Frequency ◽  
Siderastrea Stellata

Colony size-frequency distributions of reef corals may be used to infer growth potential and population responses upon environmental changes. The present paper compares the size structure of colonies of Siderastrea stellata Verrill, 1868,among 11 sites, six of them distributed along a gradient of sediment deposition in Abrolhos, Bahia, Brazil (18º S). Results indicated that the population structure is likely to be influenced by local conditions, rather than large scale factors, such as latitude. The 11 distributions, however, showed higher frequencies of small size classes. Class 1 (up to 2.5 cm diameter) was always present and the frequency of colonies from size class 3 (10 cm diameter) tended to decrease in all sites. Comparison among the six Abrolhos sites showed that S. stellata has advantages at sites with intermediate sedimentation, where colonies attain larger sizes, probably, reflecting a higher survivorship over time. The present study showed that, despite the influence of environmental conditions on parameters of the populations such as size of colony, the life history strategy of S. stellata reflects a local adaptation that allows its development and survivorship in shallow waters and horizontal substrates, sites characterized by high mortality rates.

scholarly journals Integrating structured and unstructured citizen science data to improve wildlife population monitoring

2021 ◽  
Author(s):  
Philipp H Boersch-Supan ◽  
Robert A Robinson
Keyword(s):  
Data Integration ◽  
Citizen Science ◽  
Large Scale ◽  
Population Monitoring ◽  
Analytical Framework ◽  
Good Evidence ◽  
Population Trends ◽  
Data Sources ◽  
Science Data ◽  
Widespread Species

Accurate and robust population trend assessments are key to successful biodiversity conservation. Citizen science surveys have provided good evidence of biodiversity declines whilst engaging people with them. Citizen scientists are also collecting opportunistic biodiversity records at unprecedented scales, vastly outnumbering records gathered through structured surveys. Opportunistic records exhibit spatio-temporal biases and heterogeneity in observer effort and skill, but their quantity offers a rich source of information. Data integration, the combination of multiple information sources in a common analytical framework, can potentially improve inferences about populations compared to analysing either in isolation. We combine count data from a structured citizen science survey and detection-nondetection data from an opportunistic citizen science programme. Population trends were modelled using dynamic N-mixture models to integrate both data sources. We applied this approach to two different inferential challenges arising from sparse data: (i) the estimation of population trends for an area smaller than a structured survey stratum, and (ii) the estimation of national population trends for a rare but widespread species. In both cases, data integration yielded population trajectories similar to those estimated from structured survey data alone but had higher precision when the density of opportunistic records was high. In some cases this allowed inferences about population trends where indices derived from single data sources were too uncertain to assess change. However, there were differences in the trend magnitude between the integrated and the standard survey model. We show that data integration of large-scale structured and unstructured data is feasible and offers potential to improve national and regional wildlife trend estimates, although a need to independently validate trends remains. Smaller gains are achieved in areas where uptake of opportunistic recording is low. The integration of opportunistic records from volunteer-selected locations alone may therefore not adequately address monitoring gaps for management and policy applications. To achieve the latter, scheme organisers should consider providing incentives for achieving representative coverage of target areas in both structured and unstructured recording schemes.

scholarly journals Shoreline Displacement, Coastal Environments and Human Subsistence in the Hanö Bay Region during The Mesolithic

Quaternary ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 14 ◽  
Author(s):  
Anton Hansson ◽  
Adam Boethius ◽  
Dan Hammarlund ◽  
Per Lagerås ◽  
Ola Magnell ◽  
...  
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
Extended Period ◽  
Coastal Environments ◽  
Coastal Lake ◽  
Coastal Landscape ◽  
Settlement Development ◽  
Wide Range ◽  
Shoreline Displacement ◽  
Human Subsistence

Southern Scandinavia experienced significant environmental changes during the early Holocene. Shoreline displacement reconstructions and results from several zooarchaeological studies were used to describe the environmental changes and the associated human subsistence and settlement development in the Hanö Bay region of southern Sweden during the Mesolithic. GIS-based palaeogeographic reconstructions building on shoreline displacement records from eastern Skåne and western Blekinge together with a sediment sequence from an infilled coastal lake were used to describe the environmental changes during five key periods. The results show a rapid transformation of the coastal landscape during the Mesolithic. During this time, the investigated coastal settlements indicate a shift towards a more sedentary lifestyle and a subsistence focused on large-scale freshwater fishing. The development of permanent settlements coincided with an extended period of coastline stability and the development of rich coastal environments in a more closed forest vegetation. This study provides a regional synthesis of the shoreline displacement, coastal landscape dynamics and settlement development during the Mesolithic. It also demonstrates a new way of combining zooarchaeological and palaeoecological approaches, which can produce multi-faceted and highly resolved palaeoenvironmental reconstructions in a wide range of settings.

scholarly journals When can we trust population trends? Quantifying the effects of sampling interval and duration

2018 ◽  
Author(s):  
Hannah Wauchope ◽  
Alison Johnston ◽  
Tatsuya Amano ◽  
William Sutherland
Keyword(s):  
Time Series ◽  
Large Scale ◽  
Sampling Interval ◽  
Significant Trend ◽  
Population Trends ◽  
Small Subset ◽  
Conservation Action ◽  
Scale Population ◽  
Species Population ◽  
Trend Data

AbstractSpecies’ population trends are fundamental to conservation, underpinning lUCN red-list classifications, many national lists of threatened species and are also used globally to convey to policy makers the state of nature. Clearly, it’s crucial to quantify how much we can trust population trend data. Yet many studies analyzing large numbers of population time series lack a straightforward way to estimate confidence in each trend. Here we artificially degrade 27,930 waterbird population time series to see how often subsets of the data correctly estimate the direction and magnitude of each population’s true trend. We find you need to sample many years to be confident that there is no significant trend in a population. Conversely, if a significant trend is detected, even from only a small subset of years, this is likely to be representative of the population’s true trend. This means that if a significant decline is detected in a population, it is likely to be correct and conservation action should be taken immediately, but if the trend is insignificant, confidence in this can only be high with many samples. Our full results provide a clear and quantitative way to assign confidence to species trends, and lays the foundation for similar studies of other taxa that can help to add rigor to large-scale population analyses.

Sign in / Sign up

Export Citation Format

Share Document