Large-scale Decline Research Articles

Damage to regeneration in the area after large-scale decline of Norway spruce Picea abies (L.) H. Karst. stands in the mountains

The paper presents harmful factors relevant to the health of regeneration on decline forest areas in the Sudetes and the Carpathian Mountains. It was found, that adverse atmospheric conditions and deer were the main reasons of damages occurring in most stands. Pest insects were only of marginal consequence, although they eliminated the large parts of regeneration. On decline forest areas there were distinguished three zones with different intensity of damages caused by atmospheric factors. These zones are linked to altitudinal gradient. The intensity of damages increase on higher elevations. In distinguished zones, there were specified forest management objectives and general rules for their implementation.

Growth of Western Australian Corals in the Anthropocene

Anthropogenic increases of atmospheric carbon dioxide lead to warmer sea surface temperatures and altered ocean chemistry. Experimental evidence suggests that coral calcification decreases as aragonite saturation drops but increases as temperatures rise toward thresholds optimal for coral growth. In situ studies have documented alarming recent declines in calcification rates on several tropical coral reef ecosystems. We show there is no widespread pattern of consistent decline in calcification rates of massive Porites during the 20th century on reefs spanning an 11° latitudinal range in the southeast Indian Ocean off Western Australia. Increasing calcification rates on the high-latitude reefs contrast with the downward trajectory reported for corals on Australia's Great Barrier Reef and provide additional evidence that recent changes in coral calcification are responses to temperature rather than ocean acidification.

The effect of investigator disturbance on egg laying, chick survival and fledging mass of short-tailed shearwaters (Puffinus tenuirostris) and little penguins (Eudyptula minor)

AbstractField-based animal researchers need to balance the potential adverse effects of their research activities against the benefits of research outcomes, but the data required to do this are often lacking. Assessing, and subsequently reporting the effects of researcher activities on wild animal populations can be difficult, so that studies to detect these effects sometimes lack rigour or fail to encompass sufficient time to ensure that the effects are tested under a range of environmental stresses. We monitored the effect of investigators working in colonies of two seabirds, the short-tailed shearwater (Puffinus tenuirostris) and the little penguin (Eudyptula minor). Disturbance of breeding birds while checking nests or the weighing of chicks to monitor growth are very common activities for demographic and ecological studies, but how these activities may influence the birds is rarely measured. We investigated differing levels of disturbance during both activities between 2002-03 and 2008-09 to assess their effect on egg laying, chick survival and growth rate and observed no effect for nest checking or handling of short-tailed shearwaters and indeterminate effects for handling in little penguins. Over a period of several years the study has observed a large-scale decline in the number of breeding shearwaters and includes years when control nests had above and below average breeding success.

Is the large-scale decline of the starling related to local changes in demography?

The decline of one farmland bird, the migratory European starling, has been attributed to both agricultural intensification and farmland abandonment and to factors operating both during the winter and during the breeding season. We analysed population data from thirty-three Swedish nestbox colonies over more than two decades to determine if the national decline was caused by a common factor affecting all colonies or by local changes in the breeding grounds affecting starling colonies. We found that numbers of breeding starling had declined significantly, but at different rates in different colonies. The local population sizes were affected by previous years productivity at both national and local scales, suggesting that changes in habitat quality at both scales could affect local population trends. There were no long-term trends in reproductive output, but fledgling production was lowest at intermediate years. The local population changes were positively related to local changes in reproductive output, but only when including complete nest-failures. A relationship between population declines and low mean local productivity was the result of the association between population sizes and reproductive success over time, since decline rates of starlings were not related to the average success during the first part of the study, but to the average success during the later part of the study. The relationship between population change and changes in reproductive output was evident, but fledgling production showed negative density-dependence. In conclusion this study suggests that the decline of the starling population in Sweden has been affected by processes at small spatial scales during the breeding season affecting reproductive success, but does not exclude an additional role for processes at large spatial scales or outside the breeding season.

Usefulness of volunteer data to measure the large scale decline of “common” toad populations

Measuring a species decline is pivotal to evaluate their conservation status, but an accurate assessment of demographic trends requires observations collected across broad spatial and temporal scales. Volunteers can help to collect information over large scales, but their data may be affected by heterogeneity for sampling efforts and protocols, which may influence detection probability. Ignoring this issue may conduct to misleading conclusions. Here we show that data collected by different volunteer groups can be integrated with measures of sampling efforts, to obtain information on large scale demographic trends. We collected data on 33 common toad ( Bufo bufo) populations across Italy for the period 1993–2010. We used two approaches (meta-analysis; analysis of average change in population size) to evaluate the overall demographic trend. We incorporated measures of volunteer sampling efforts into analyses, to take into account changes in detection probability. Toad abundance significantly declined in the last decade. From 2000 to 2010, 70% of populations showed a strong decline, and only 10% increased. Trends were heterogeneous among populations, but taking into account sampling effort reduced heterogeneity by 40%. We detected a 76% cumulative average decline of toad populations, despite an increasing mean sampling effort. The widespread toad decline rises concern for its future, also because the causes remain unclear. Volunteer data can be extremely useful to identify large scale population trends, if information on sampling effort are recorded and used to adjust counts.

The 10 Australian ecosystems most vulnerable to tipping points

We identify the 10 major terrestrial and marine ecosystems in Australia most vulnerable to tipping points, in which modest environmental changes can cause disproportionately large changes in ecosystem properties. To accomplish this we independently surveyed the coauthors of this paper to produce a list of candidate ecosystems, and then refined this list during a 2-day workshop. The list includes (1) elevationally restricted mountain ecosystems, (2) tropical savannas, (3) coastal floodplains and wetlands, (4) coral reefs, (5) drier rainforests, (6) wetlands and floodplains in the Murray-Darling Basin, (7) the Mediterranean ecosystems of southwestern Australia, (8) offshore islands, (9) temperate eucalypt forests, and (10) salt marshes and mangroves. Some of these ecosystems are vulnerable to widespread phase-changes that could fundamentally alter ecosystem properties such as habitat structure, species composition, fire regimes, or carbon storage. Others appear susceptible to major changes across only part of their geographic range, whereas yet others are susceptible to a large-scale decline of key biotic components, such as small mammals or stream-dwelling amphibians. For each ecosystem we consider the intrinsic features and external drivers that render it susceptible to tipping points, and identify subtypes of the ecosystem that we deem to be especially vulnerable.

Drought alters timing, quantity, and quality of wood formation in Scots pine

Drought has been frequently discussed as a trigger for forest decline. Today, large-scale Scots pine decline is observed in many dry inner-Alpine valleys, with drought discussed as the main causative factor. This study aimed to analyse the impact of drought on wood formation and wood structure. To study tree growth under contrasting water supply, an irrigation experiment was installed in a mature Scots pine (Pinus sylvestris L.) forest at a xeric site in a dry inner-Alpine valley. Inter- and intra-annual radial increments as well as intra-annual variations in wood structure of pine trees were studied. It was found that non-irrigated trees had a noticeably shorter period of wood formation and showed a significantly lower increment. The water conduction cells were significantly enlarged and had significantly thinner cell walls compared with irrigated trees. It is concluded that pine trees under drought stress build a more effective water-conducting system (larger tracheids) at the cost of a probably higher vulnerability to cavitation (larger tracheids with thinner cell walls) but without losing their capability to recover. The significant shortening of the growth period in control trees indicated that the period where wood formation actually takes place can be much shorter under drought than the 'potential' period, meaning the phenological growth period.

Introduction to Aging, Cancer, and Age‐related Diseases

A rising tide of chronic age-dependent diseases, co-morbidities, and geriatric syndromes--a veritable Silver Tsunami--will soon present serious challenges for North America, Europe, Japan, and other industrialized nations. Meanwhile, a growing number of scientists, led by biogerontologists, maintain that the key to blunting the societal impact of large-scale decline and disability among older populations lies with better understanding and potential manipulation of biological mechanisms of aging itself. Well-characterized interventions that slow aging and extend health and vigor in animal models may be forerunners of technologies that preserve additional years of healthy productive life in humans. What will it take to validate these momentous insights from biogerontology and their potential applications for human populations? What are the points of resistance for key opinion leaders and policy makers? And how can biogerontologists make common cause with those outside the discipline to inform larger and more politically powerful audiences?

The role of seedlings and seed bank viability in the recovery of Chesapeake Bay, USA, Zostera marina populations following a large-scale decline

The objective of this study was to quantify the spatial and temporal recolonization characteristics of Zostera marina beds in the lower Chesapeake Bay following large scale declines in the late summer of 2005. Transects were established and monitored monthly for changes in eelgrass abundance at three sites (two downriver, one upriver) in the York River from April–October 2006 and 2007. Measurements included percent bottom cover, above ground biomass, shoot density, shoot origin (seedling or vegetative), seed bank abundance and seed viability. During 2006, the eelgrass beds at all sites recovered with seedlings providing the largest proportion of the total shoot abundance. This trend shifted in 2007 and surviving vegetative shoots were the dominant component of shoot standing crop. A second consecutive decline related to low light conditions occurred during the summer of 2006 in the upriver site and recovery there was minimal in 2007. These results highlight that after a single die off event, seed germination with subsequent seedling growth is the principal method for revegetation in lower Chesapeake Bay Z. marina beds. However, no viable seeds remain in the seed bank during this first year of recovery and shoots produced by the seedling growth do not flower and produce seeds until their second year of growth. Therefore the seed-bank density is low and is not immediately replenished. This suggests that the resiliency of perennial Chesapeake Bay Z. marina populations to repeated disturbances is restricted and repeated annual stress may result in much longer term bed loss.

Effects of forest landscape change and management on the range expansion of forest bird species in the Mediterranean region

In the western Mediterranean region of Catalonia (NE Spain), during the last 20 years of the 20th century, the range of many forest bird species has expanded. Our objective was to characterize the roles of (a) spatial population processes (related to dispersal), (b) changes in forest structure (due to forest maturation and management), and (c) landscape composition (resulting from afforestation and fires) in the range expansion of these bird species at the landscape scale (10 × 10 km). After correcting for the differences in sampling effort, colonizations appeared to be more likely near areas in which the species had been present in the 1980s. Patterns of the range expansion were also strongly associated with forest maturation, which seems to affect the spatial arrangement of birds at multiple scales. Changes in forest landscape composition due to afforestation and fires were minor determinants of range changes, and forest management did not seem to prevent range expansion at the spatial scale studied. Colonization events appeared to be driven primarily by landscape changes occurring in nearby localities rather than within the colonized locations themselves, presumably because of source–sink dynamics and connectivity patterns. Our results showed that in Catalonia, at a landscape scale, the impact of forest management on forest bird communities is much smaller than the impact of the widespread maturation of forests following a large-scale decline in traditional uses.

A Study of Turf: Historic Rural Settlements in Scotland and Iceland

The ruins of abandoned settlements remain visible throughout much of rural Scotland. These represent former townships, farmsteads and shielings which were widespread until relatively recently and began their fall into large-scale decline and abandonment during the eighteenth century. Despite being such a common feature in the landscape relatively few of these abandoned settlements have been recorded in any detail. Since October 2006 the Scotland's Rural Past Project at the Royal Commission on the Ancient and Historical Monuments of Scotland (RCAHMS) has been working with community groups to discover, survey, and record a small fraction of the thousands of these sites that have the potential to tell a story of rural settlement from the medieval period onwards.1

North American arthropods at risk due to widespread Fraxinus mortality caused by the Alien Emerald ash borer

Emerald ash borer (Agrilus planipennis Fairmaire) (EAB), an alien invasive wood-boring buprestid beetle, is causing large-scale decline and mortality of the most widely distributed species of ash (Fraxinus spp.) trees endemic to eastern North America. We determined which arthropod species that are associated with ash may become threatened, endangered, and co-extinct with the demise of ash as a dominant tree species. A literature survey revealed that 43 native arthropod species in six taxonomic groups (Arachnida: Acari; Hexapoda: Coleoptera, Diptera, Hemiptera, Hymenoptera, and Lepidoptera) are known to be associated only with ash trees for either feeding or breeding purposes, and thus face high risk of endangerment. Most of these species are gall-formers followed by folivores, subcortical phloem/xylem feeders, sap feeders, and seed predators. Another 30 arthropod species are associated with 1-2 host plants in addition to ash, and herbivory on these hosts may increase as these arthropods shift from declining ash trees. Extirpation of arthropods depen- dent upon ash may unleash multiple extinctions of affiliated species with which they may be inextricably linked. The demise of North American ash species due to EAB is expected to lead to biotic loss with cascading ecological impacts and altered processes within forested ecosystems.

Polar firn air reveals large-scale impact of anthropogenic mercury emissions during the 1970s

Mercury (Hg) is an extremely toxic pollutant, and its biogeochemical cycle has been perturbed by anthropogenic emissions during recent centuries. In the atmosphere, gaseous elemental mercury (GEM; Hg degrees ) is the predominant form of mercury (up to 95%). Here we report the evolution of atmospheric levels of GEM in mid- to high-northern latitudes inferred from the interstitial air of firn (perennial snowpack) at Summit, Greenland. GEM concentrations increased rapidly after World War II from approximately 1.5 ng m(-3) reaching a maximum of approximately 3 ng m(-3) around 1970 and decreased until stabilizing at approximately 1.7 ng m(-3) around 1995. This reconstruction reproduces real-time measurements available from the Arctic since 1995 and exhibits the same general trend observed in Europe since 1990. Anthropogenic emissions caused a two-fold rise in boreal atmospheric GEM concentrations before the 1970s, which likely contributed to higher deposition of mercury in both industrialized and remotes areas. Once deposited, this toxin becomes available for methylation and, subsequently, the contamination of ecosystems. Implementation of air pollution regulations, however, enabled a large-scale decline in atmospheric mercury levels during the 1980s. The results shown here suggest that potential increases in emissions in the coming decades could have a similar large-scale impact on atmospheric Hg levels.

Human Factors and the Nuclear Renaissance

Following the Three Mile Island incident and the Chernobyl accident, there was a general decline in public acceptance of nuclear power plants. Consequently, there was a heavy push to ensure the safety of existing plants coupled with a large-scale decline in the development of new plants. This situation has posed unique challenges to human factors within the nuclear industry. The emphasis of research came in the form of ensuring the safety of as-built systems. This approach clashed with broader human factors work, which used a variety of innovative approaches to design novel or incrementally improved interfaces. The situation is changing now. As current plants near the end of their operational life, there is an urgent need to develop new plants and modernize aging plants to sustain current energy production levels and, in many countries, to meet growing power demands. The resurgence of interest in nuclear energy has been called the “nuclear renaissance.” The challenge for human factors is now to go beyond as-built safety requirements and provide innovative interface concepts that maximize human performance in new plants. The purpose of this panel is to bring together established and new human factors professionals in nuclear energy to discuss the opportunities and challenges for research, practice, and regulation of this nuclear renaissance.

Response of the Norway spruce (Picea abies [L.] Karst.) root system to changing humidity and temperature conditions of the site

The Bohemian-Moravian Upland shows a large-scale decline and dieback of Norway spruce up to the forest altitudinal vegetation zone (FAVZ) 5. This phenomenon has been observed in the last 7 years and its progress is rapid. Healthy, declining and standing dry trees of equal height were mutually compared in nine forest stands (aged 3–73 years). These parameters were measured: increment dynamics, root system architecture, biomass, fine root vitality and mycorrhiza, infestation by biotic and abiotic agents. Analyses were done for 414 trees, soil characteristics and weather course data covered the period 1961–2004. Warming and precipitation deficit are the predisposition factors. Weakened trees are aggressively infested by the honey fungus (<I>Armillaria mellea</I>), and they die from root rots. In this paper we describe the mechanism of damage to and dieback of the spruce trees concerned.

Large-scale decline in offshore seagrass meadows in Bermuda

Bermuda is an isolated 5560 ha chain of limestone islands on a 150 000 ha seamount located near 32° N, 64° W. Meadows of tropical and subtropical seagrasses, dominated by Thalassia testudinum and Syringodium filiforme, are found from inshore bays out to the inner edge of the rim reef that encircles the platform. Fine-scale computerized mapping and subsequent broad-scaled field assessment of seagrass meadows in Bermuda show that (1) meadows representing nearly one-quar- ter of the territory's total seagrass area in 1997 had declined by 2004, (2) net loss of seagrass mead- ows occurred at rim reef and lagoonal locations that are far-removed from anthropogenic distur- bances, (3) the decline appears to have been in progress as early as 1996, and (4) both T. testudinum and S. filiforme meadows declined. Nearly 2100 ha of meadows were visible in a 1997 geo- referenced mosaic of aerial photographs of the Bermuda platform. In 2004, 22 meadows that repre- sented about 475 of the 900 ha of offshore seagrass identified in 1997 and earlier were absent or in obvious decline. The size and location of inshore and nearshore meadows, which are exposed to intense anthropogenic stresses and physical damage, varied over the same 7 yr but their total area has either remained unchanged or even increased. Processes contributing to the decline in offshore meadows have yet to be determined, but may include herbivory by juvenile green turtles and parrot- fishes and below-normal productivity owing to a winter cold-water event correlated with a change in the North Atlantic Oscillation (NAO) in 1996. The potential consequences to Bermuda of the loss of nearly 500 ha of critical marine habitat are of extreme concern.

Perimenopausal Mental Disorders: Epidemiology and Phenomenology

Perimenopause, the interval of irregular menstrual activity which directly precedes menopause, is characterized by widely fluctuating hormone levels amidst a large-scale decline in circulating estrogen. This phase in a woman's life is typically accompanied by physical discomforts including vasomotor symptoms, such as headaches, insomnia, and hot flushes, as well as genital atrophy. Not surprisingly, studies suggest a significant increase in mood lability for women during this time. While some evidence points toward an exacerbation of bipolar mood symptoms and an increase in schizophrenic psychosis during perimenopause, the majority of research conducted on perimenopausal mental disorders has focused on unipolar depression. Studies vary widely in methodology, definitions of menopausal status, and degrees of depression among subjects; however, the majority of findings indicate an increased susceptibility to depression during the perimenopausal transition. This greater susceptibility may be due to neuroendocrine effects of declining estrogen levels, the subjective experience of somatic symptoms resulting from this hormonal decline, and/or the more frequent occurrence of "exit" or "loss" events for women during this stage of life. At this time, more research is needed to address questions of prevalence, risk, and etiology for depression and other major mental disorders as related to the physiological and psychosocial changes associated with perimenopause.

Mining, migration and immobility: towards an understanding of the relationship between migration and occupation in the context of the UK mining industry

AbstractThe large‐scale decline of the UK mining industry in recent years has led to significant job losses, unemployment and inactivity throughout the coalfields. This paper aims to examine the role of migration as a response to these closures during the last 30 years. In neo‐classical economic theory, migration is traditionally seen as an equilibrating force in areas of labour‐market imbalance. However, this paper argues that migration is more closely associated with occupation than with imbalances in the demand and supply of labour, with professional workers displaying far higher rates of migration than manual workers. While migration is often seen as an integral part of many professional careers, by contrast it has little to do with the nature of manual occupations. Consequently, it is argued that the labour‐market problems faced by manual workers, such as miners, are unlikely to be alleviated by labour migration. In order to illustrate these arguments, the paper uses data from the Sample of Anonymised Records and the ONS Longitudinal Study. The migration rates of miners are compared with other occupational groups; migration rates over time are considered; and transitions in employment are examined. Copyright © 2002 John Wiley & Sons, Ltd.

Density, spatial distribution and size structure of sea urchins in Florida Keys coral reef and hard-bottom habitats

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 235:117-126 (2002) - doi:10.3354/meps235117 Density, spatial distribution and size structure of sea urchins in Florida Keys coral reef and hard-bottom habitats Mark Chiappone1,*, Dione W. Swanson2, Steven L. Miller1 1Center for Marine Science Research and NOAA¹s National Undersea Research Center, University of North Carolina at Wilmington, 515 Caribbean Drive, Key Largo, Florida 33037, USA 2Division of Marine Biology and Fisheries, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA *E-mail: chiapponem@uncwil.edu ABSTRACT: The 1983-84 Caribbean-wide mortality of the long-spined sea urchin Diadema antillarum Philippi was followed by a 2nd mortality event during 1991 in the Florida Keys. Pre-mortality sea urchin densities were up to 5 ind. m-2 and the large scale decline of D. antillarum is considered to be 1 factor affecting community dynamics of Florida Keys reefs. During 1999-2000, we surveyed 125 sites using a stratified random sampling design in shallow-water coral reef and hard-bottom habitats. Strip transects were sampled to assess density, habitat utilization and size structure patterns among habitat types, regional sectors and between fished and protected areas. Nearly 17 yr after the mass mortality, D. antillarum has not recovered to pre-1983 levels, with current densities no greater than 0.05 ind. m-2, and small test sizes (1 to 2 cm) dominate. Other sea urchins such as Eucidaris tribuloides (Lamarck) and Echinometra viridis Agassiz show density and habitat distribution patterns similar to historical observations. KEY WORDS: Coral reefs · Florida Keys · Herbivory · Marine reserves · Population density · Recruitment · Sea urchins · Size structure Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 235. Online publication date: June 19, 2002 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2002 Inter-Research.

Recolonization pattern of the polychaete Lanice conchilega on an intertidal sand flat following the severe winter of 1995/96

The recolonization process of Lanice conchilega was studied on an intertidal sand flat in the northern Wadden Sea after an intertidal population had been wiped out during the severe winter of 1995/96. After very low recruitment in the first two years, the population fully recovered in the third year after its destruction. By then, the distribution pattern closely resembled the pattern before the severe winter with >95% of all Lanice occurring below –0.5 m mean tidal level and dominance of the density categories 6–50 individuals (ind) m–2 and 51–200 ind m–2. Lanice larvae have been observed to attach preferentially on the tubes of adults. However, the high recruitment in the third year was also seen in areas devoid of adult Lanice, indicating that settlement facilitation by adults was of little importance for the recolonization process. Instead, we suggest that the observed recruitment pattern was a consequence of a large-scale decline in the metapopulation in the tidal basin and the onshore coastal subtidal which resulted in insufficient larval supply onto the tidal flats and low recruitment in the first two years following the severe winter.