scholarly journals Effect of the Long-Term Mean and the Temporal Stability of Water-Energy Dynamics on China’s Terrestrial Species Richness

2017 ◽  
Vol 6 (3) ◽  
pp. 58 ◽  
Author(s):  
Chunyan Zhang ◽  
Danlu Cai ◽  
Wang Li ◽  
Shan Guo ◽  
Yanning Guan ◽  
...  
2021 ◽  
pp. 089020702110173
Author(s):  
Nadin Beckmann ◽  
Damian P Birney ◽  
Amirali Minbashian ◽  
Jens F Beckmann

The study aimed to investigate the status of within-person state variability in neuroticism and conscientiousness as individual differences constructs by exploring their (a) temporal stability, (b) cross-context consistency, (c) empirical links to selected antecedents, and (d) empirical links to longer term trait variability. Employing a sample of professionals ( N = 346) from Australian organisations, personality state data together with situation appraisals were collected using experience sampling methodology in field and repeatedly in lab-like settings. Data on personality traits, cognitive ability, and motivational mindsets were collected at baseline and after two years. Contingent (situation contingencies) and non-contingent (relative SD) state variability indices were relatively stable over time and across contexts. Only a small number of predictive effects of state variability were observed, and these differed across contexts. Cognitive ability appeared to be associated with state variability under lab-like conditions. There was limited evidence of links between short-term state and long-term trait variability, except for a small effect for neuroticism. Some evidence of positive manifold was found for non-contingent variability. Systematic efforts are required to further elucidate the complex pattern of results regarding the antecedents, correlates and outcomes of individual differences in state variability.


Author(s):  
Katherine C Kral-O’Brien ◽  
Adrienne K Antonsen ◽  
Torre J Hovick ◽  
Ryan F Limb ◽  
Jason P Harmon

Abstract Many methods are used to survey butterfly populations, with line transect and area surveys being prominent. Observers are typically limited to search within 5 or 10 m from the line, while observers are unrestricted in larger specified search regions in area surveys. Although methods differ slightly, the selection is often based on producing defendable data for conservation, maximizing data quality, and minimizing effort. To guide method selection, we compared butterfly surveys using 1) line versus area methods and 2) varying width transects (5 m, 10 m, or unrestricted) using count data from surveys in North Dakota from 2015 to 2018. Between line and area surveys, we detected more individuals with area surveys, even when accounting for effort. However, both methods accumulated new species at similar rates. When comparing transect methodology, we detected nearly 60% more individuals and nine more species when transect width increased from 5 m to unrestricted, despite similar effort across methodology. Overall, we found line surveys slightly less efficient at detecting individuals, but they collected similar species richness to area surveys when accounting for effort. Additionally, line surveys allow the use of unrestricted-width transects with distance sampling procedures, which were more effective at detecting species and individuals while providing a means to correct count data over the same transect length. Methods that reduce effort and accurately depict communities are especially important for conservation when long-term datasets are unavailable.


2021 ◽  
Author(s):  
Christopher Jury ◽  
Keisha Bahr ◽  
Evan Barba ◽  
Russell Brainard ◽  
Annick Cros ◽  
...  

Abstract Coral reefs are among the most sensitive ecosystems affected by ocean acidification and warming, and are predicted to shift from net accreting calcifier-dominated systems to net eroding algal-dominated systems over the coming decades. Here we present a long-term experimental study examining the responses of entire mesocosm coral reef communities to acidification (-0.2 pH units), warming (+ 2°C), and combined future ocean (-0.2 pH, + 2°C) treatments. We show that under future ocean conditions, net calcification rates declined yet remained positive, corals showed reduced abundance yet were not extirpated, and community composition shifted while species richness was maintained. Our results suggest that under Paris Climate Agreement targets, coral reefs could persist in an altered functional state rather than collapse.


2014 ◽  
Vol 11 (1) ◽  
pp. 331-390
Author(s):  
M. Lipizer ◽  
E. Partescano ◽  
A. Rabitti ◽  
A. Giorgetti ◽  
A. Crise

Abstract. An updated climatology, based on a comprehensive dataset (1911–2009) of temperature, salinity and dissolved oxygen, has been produced for the whole Adriatic Sea with the Variational Inverse Method using the DIVA software. Climatological maps were produced at 26 levels and validated with Ordinary Cross Validation and with real vs. synthetic Temperature–Salinity diagram intercomparison. The concept of Climatology–Observation Misfit (COM) has been introduced as an estimate of the physical variability associated with the climatological structures. In order to verify the temporal stability of the climatology, long-term variability has been investigated in the Mid Adriatic and the South Adriatic Pits, regarded as the most suitable records of possible long-term changes. Compared with previous climatologies, this study reveals a surface temperature rise (up to 2 °C), a clear deep dissolved oxygen minimum in the South Adriatic Gyre and a bottom summer oxygen minimum in the North Adriatic. Below 100 m all properties profoundly differ between the Middle and the South Adriatic. The South Adriatic Pit clearly shows the remote effects of the Eastern Mediterranean Transient, while no effect is observed in Middle Adriatic Pits. The deepest part of the South Adriatic seems now to be significantly saltier (+0.18 since the period 1911–1914, with an increase of +0.018 decade−1 since the late 1940s) and warmer (+0.54 °C since 1911–1914), even though a long-term temperature trend could not be statistically demonstrated. Conversely, the Middle Adriatic Pits present a long-term increase in apparent oxygen utilisation (+0.77 mL L−1 since 1911–1914, with a constant increase of +0.2 mL L−1 decade−1 after the 1970s).


2021 ◽  
Author(s):  
◽  
Sean David Cooper

<p>Ecosystem-based management (EBM) has become an increasingly popular concept for government agencies to incorporate into management planning strategies. The basic idea behind EBM is that an ecosystem remains intact, resilient and productive in the long-term, to provide for ecological, social, cultural and economic benefits. The problem that decision makers face is that there is often little information regarding the structure and functioning of ecosystems upon which to base meaningful decisions. A further complication is that governance of the environment is highly sectoral both across government and within agencies. This often leads to fractured management between the terrestrial, freshwater and marine environments, potentially risking biodiversity loss and the stability of ecosystems.  Small oceanic islands may potentially be model ecosystems for undertaking ecological studies, due to their constrained spatial extent and often unmodified condition. The New Zealand Subantarctic Islands, which are remote and largely unmodified, provide a natural laboratory to study the structure and functioning of ecosystems. I undertook stable isotope and water nutrient sampling to describe the trophic structure, trophic interactions and the drivers of the Antipodes and Bounty Islands, two of the islands in New Zealand’s Subantarctic region. These islands have high conservation value and are an important area for breeding seabirds and marine mammals, but there have been no studies at these islands to understand how they function and what the connections are between the terrestrial and marine environments.  Using the stable isotope signatures of nitrogen (δ¹⁵N) and carbon (δ¹³C) from a wide range of common marine and terrestrial species at both islands, I described the trophic structure of each island. I found that the islands had a similar number of trophic levels and that omnivory was present beyond secondary consumers and below top level predators. Antipodes Island had a more complex food web than the Bounty Islands, but both islands showed strong linkages between the terrestrial and marine environments at both a local scale and with habitats beyond the sovereignty area of New Zealand.  A basic two-source mixing model was used to determine the carbon sources that were important at each island. It was found that the Antipodes Island marine communities were influenced by phytoplankton, but that kelp was also an important contributor of carbon to consumers’ diets. In contrast, at the Bounty Islands, phytoplankton was the sole carbon source in marine communities. Terrestrial species at both islands had a marine-derived carbon component to their diets, with Antipodes Island terrestrial species incorporating a combination of terrestrial-derived and marine-derived carbon. The Bounty Islands’ terrestrial species were completely reliant on marine-derived carbon that was linked to phytoplankton. To further test the diets of species, Isosource was used to reconstruct the diets of the most common marine invertebrates and terrestrial species, again demonstrating strong marine-terrestrial links.  To determine if there was any correlation between the distance from shore, water nutrient concentrations and phytoplankton stable isotope signatures, samples were collected in open ocean sites across the Campbell Plateau and within 12 nautical miles of each island. It was found that the nitrate levels of Antipodes Island water samples decreased with distance towards the island and that nitrate and dissolved reactive phosphorous levels increased with distance towards the Bounty Islands.  This research has clearly demonstrated that there is a strong link between the marine and terrestrial realms at both islands and at spatial scales beyond the islands. The current management of the islands requires this new information to be taken into consideration in future management planning, so that trophic connections are maintained across realms. Further work is required across government and within agencies to bring legislation, policy and science into an integrated framework across sectors. This will allow environmental managers to reduce threats at the ecosystem level to minimise biodiversity loss and the risk of degradation of ecosystems, to protect New Zealand’s long-term biodiversity, social, cultural and economic prosperity.</p>


2016 ◽  
Author(s):  
Rosa Delia García ◽  
Emilio Cuevas ◽  
Omaira Elena García ◽  
Ramon Ramón ◽  
Pedro Miguel Romero-Campos ◽  
...  

Abstract. A 1-year intercomparison of classical and modern radiation and sunshine duration instruments has been performed at Izaña Atmospheric Observatory (IZO) located in Tenerife (Canary Islands, Spain) starting on July 17, 2014. We compare global solar radiation (GSR) records measured with a CM-21 pyranometer Kipp &amp; Zonen, taken in the framework of the Baseline Surface Radiation Network, with those measured with a Multifilter Rotating Shadowband Radiometer (MFRSR), and a bimetallic pyranometer (PYR), and GSR estimated from sunshine duration performed by a Campbell-Stokes sunshine recorder (CS) and a Kipp &amp; Zonen sunshine duration sensor (CSD). Given the GSR BSRN records are subject of strict quality controls (based on principles of physical limits and comparison with the LibRadtran model), they have been used as reference in the intercomparison study. We obtain an overall root mean square error (RMSE) of ~0.9 MJm2 (4 %) for GSR PYR and GSR MFRSR, 1.9 MJm2 (7 %) and 1.2 MJm2 (5 %) for GSR CS and GSR CSD, respectively. Factors such as temperature, fraction of the clear sky, relative humidity and the solar zenith angle have shown to moderately affect the GSR observations. As application of the methodology developed in this work, we have re-evaluated the GSR time series between 1977 and 1991 obtained with two PYRs at IZO. By comparing with coincident GSR estimates from SD observations, we probe the high consistency of those measurements and their temporal stability. These results demonstrate that 1) the continuous-basis intercomparison of different GSR techniques offers important diagnostics for identifying inconsistencies between GSR data records, and 2) the GSR measurements performed with classical and more simple instruments are consistent with more modern techniques and, thus, valid to recover GSR time series and complete worldwide distributed GSR data. The intercomparison and quality assessment of these different techniques have allowed to obtain a complete and consistent long-term global solar radiation series (1977–2015) at Izaña.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7330
Author(s):  
Teemu Saikkonen ◽  
Varpu Vahtera ◽  
Seppo Koponen ◽  
Otso Suominen

The effect of reindeer Rangifer tarandus L. grazing on the ground-dwelling spider assemblage in Northern Finland was studied. Changes in species richness, abundance and evenness of spider assemblages were analyzed in relation to changes in vegetation and environmental factors in long term grazed and ungrazed sites as well as sites that had recently switched from grazed to ungrazed and vice versa. Grazing was found to have a significant impact on height and biomass of lichens and other ground vegetation. However, it seemed not to have an impact on the total abundance of spiders. This is likely caused by opposing family and species level responses of spiders to the grazing regime. Lycosid numbers were highest in grazed and linyphiid numbers in ungrazed areas. Lycosidae species richness was highest in ungrazed areas whereas Linyphiidae richness showed no response to grazing. Four Linyphiidae, one Thomisidae and one Lycosidae species showed strong preference for specific treatments. Sites that had recovered from grazing for nine years and the sites that were grazed for the last nine years but were previously ungrazed resembled the long term grazed sites. The results emphasize the importance of reindeer as a modifier of boreal forest ecosystems but the impact of reindeer grazing on spiders seems to be family and species specific. The sites with reversed grazing treatment demonstrate that recovery from strong grazing pressure at these high latitudes is a slow process whereas reindeer can rapidly change the conditions in previously ungrazed sites similar to long term heavily grazed conditions.


1999 ◽  
Vol 29 (7) ◽  
pp. 1101-1111 ◽  
Author(s):  
Steven G Newmaster ◽  
F Wayne Bell ◽  
Dale H Vitt

The effects of two silvicultural herbicides (Vision®, Release®) on bryophytes and lichens were studied in a harvested boreal mixedwood ecosystem. A completely randomized design with 115 plots of 1 m2 allowed direct comparison between herbicides and their effects on community dynamics. Regression models were used to analyze the relationship between herbicide application rates (0.71-6.72 kg active ingredient/ha) and changes in bryophyte and lichen abundance and species richness for 2 years following herbicide application. Results showed that bryophyte and lichen abundance and species richness decreased after herbicide treatments. In general, herbicide applications reduced the diversity of forest mesophytes and weedy colonizers to an ecosystem with only a few species of colonizers. A combination of clustering techniques and ANOVA were used to divide bryophytes and lichens into three ecologically defined response groups: herbicide-tolerant colonizers, semi tolerant long-term stayers from dry open forest, and sensitive forest mesophytes.


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