The importance of long‐term social‐ecological research for the future of restoration ecology

In the face of rapid environmental and cultural change, long‐term ecological research (LTER) and social‐ecological research (LTSER) are more important than ever. LTER contributes disproportionately to ecology and policy, evidenced by the greater proportion of LTER in higher impact journals and the disproportionate representation of LTER in reports informing policymaking. Historical evidence has played a significant role in restoration projects and it will continue to guide restoration into the future, but its use is often hampered by lack of information, leading to considerable uncertainties. By facilitating the storage and retrieval of historical information, LTSER will prove valuable for future restoration.     

Long‐term ecological monitoring and institutional memories

Many important ecological management issues can only be addressed by long‐term monitoring or through studies carried out over extended periods. But such studies require institutional settings that ensure funding is sustained and that data arising from these studies are securely managed. Recent experience suggests both are difficult to achieve. This is because management agencies and research bodies are periodically restructured, especially in recent years. This has often led to long‐term work being terminated. But there is anecdotal evidence that the data collected in at least some of these studies are not always lost. Instead, it can remain stored in the back rooms of agencies or in the personal files of former staff. Such data are clearly at risk; with time fewer people remain aware of the work or of the existence of data that were collected, thereby increasing the likelihood that the information will eventually disappear. This seems a waste. Securing funds for any long‐term ecological study is always likely to be difficult, and many of these previous long‐term studies are likely to be relevant to some of our present management problems. One approach to taking advantage of these earlier studies would be to ask scientific and professional associations to survey their older members to identify relevant previous investigations. But any re‐establishment of former studies will require the creation of new institutional arrangements, more robust institutional memories and sufficient funds that are able to sustain any resurrected investigations into the future.     

Plastic pollution in croplands threatens long‐term food security

Plastic pollution is a global concern given its prevalence in aquatic and terrestrial ecosystems. Studies have been conducted on the distribution and impact of plastic pollution in marine ecosystems, but little is known on terrestrial ecosystems. Plastic mulch has been widely used to increase crop yields worldwide, yet the impact of plastic residues in cropland soils to soil health and crop production in the long term remained unclear. In this paper, using a global meta‐analysis, we found that the use of plastic mulch can indeed increase crop yields on average by 25%–42% in the immediate season due to the increase of soil temperature (+8%) and moisture (+17%). However, the unabated accumulation of film residues in the field negatively impacts its physicochemical properties linked to healthy soil and threatens food production in the long term. It has multiple negative impacts on plant growth including crop yield (at the mean rate of ?3% for every additional 100 kg/ha of film residue), plant height (?2%) and root weight (?5%), and soil properties including soil water evaporation capacity (?2%), soil water infiltration rate (?8%), soil organic matter (?0.8%) and soil available phosphorus (?5%) based on meta‐regression. Using a nationwide field survey of China, the largest user of plastic mulch worldwide, we found that plastic residue accumulation in cropland soils has reached 550,800 tonnes, with an estimated 6%–10% reduction in cotton yield in some polluted sites based on current level of plastic residue content. Immediate actions should be taken to ensure the recovery of plastic film mulch and limit further increase in film residue loading to maintain the sustainability of these croplands.     

Acclimation to ocean acidification during long‐term CO2 exposure in the cold‐water coral Lophelia pertusa

Ocean acidity has increased by 30% since preindustrial times due to the uptake of anthropogenic CO₂ and is projected to rise by another 120% before 2100 if CO₂ emissions continue at current rates. Ocean acidification is expected to have wide‐ranging impacts on marine life, including reduced growth and net erosion of coral reefs. Our present understanding of the impacts of ocean acidification on marine life, however, relies heavily on results from short‐term CO₂ perturbation studies. Here, we present results from the first long‐term CO₂ perturbation study on the dominant reef‐building cold‐water coral Lophelia pertusa and relate them to results from a short‐term study to compare the effect of exposure time on the coral's responses. Short‐term (1 week) high CO₂ exposure resulted in a decline of calcification by 26–29% for a pH decrease of 0.1 units and net dissolution of calcium carbonate. In contrast, L. pertusa was capable to acclimate to acidified conditions in long‐term (6 months) incubations, leading to even slightly enhanced rates of calcification. Net growth is sustained even in waters sub‐saturated with respect to aragonite. Acclimation to seawater acidification did not cause a measurable increase in metabolic rates. This is the first evidence of successful acclimation in a coral species to ocean acidification, emphasizing the general need for long‐term incubations in ocean acidification research. To conclude on the sensitivity of cold‐water coral reefs to future ocean acidification further ecophysiological studies are necessary which should also encompass the role of food availability and rising temperatures.     

Impacts of long‐term elevated atmospheric CO2 concentrations on communities of arbuscular mycorrhizal fungi

The ecological impacts of long‐term elevated atmospheric CO₂ (eCO₂) levels on soil microbiota remain largely unknown. This is particularly true for the arbuscular mycorrhizal (AM) fungi, which form mutualistic associations with over two‐thirds of terrestrial plant species and are entirely dependent on their plant hosts for carbon. Here, we use high‐resolution amplicon sequencing (Illumina, HiSeq) to quantify the response of AM fungal communities to the longest running (>15 years) free‐air carbon dioxide enrichment (FACE) experiment in the Northern Hemisphere (GiFACE); providing the first evaluation of these responses from old‐growth (>100 years) semi‐natural grasslands subjected to a 20% increase in atmospheric CO₂. eCO₂ significantly increased AM fungal richness but had a less‐pronounced impact on the composition of their communities. However, while broader changes in community composition were not observed, more subtle responses of specific AM fungal taxa were with populations both increasing and decreasing in abundance in response to eCO₂. Most population‐level responses to eCO₂ were not consistent through time, with a significant interaction between sampling time and eCO₂ treatment being observed. This suggests that the temporal dynamics of AM fungal populations may be disturbed by anthropogenic stressors. As AM fungi are functionally differentiated, with different taxa providing different benefits to host plants, changes in population densities in response to eCO₂ may significantly impact terrestrial plant communities and their productivity. Thus, predictions regarding future terrestrial ecosystems must consider changes both aboveground and belowground, but avoid relying on broad‐scale community‐level responses of soil microbes observed on single occasions.     

Long‐term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia): survey methods,data management,and long‐term population trends

Long‐term observational studies conducted at large (regional) spatial scales contribute to better understanding of landscape effects on population and evolutionary dynamics, including the conditions that affect long‐term viability of species, but large‐scale studies are expensive and logistically challenging to keep running for a long time. Here, we describe the long‐term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia) that has been conducted since 1991 in a large network of 4000 habitat patches (dry meadows) within a study area of 50 by 70 km in the Åland Islands in Finland. We explain how the landscape structure has been described, including definition, delimitation, and mapping of the habitat patches; methods of field survey, including the logistics, cost, and reliability of the survey; and data management using the EarthCape biodiversity platform. We describe the long‐term metapopulation dynamics of the Glanville fritillary based on the survey. There has been no long‐term change in the overall size of the metapopulation, but the level of spatial synchrony and hence the amplitude of fluctuations in year‐to‐year metapopulation dynamics have increased over the years, possibly due to increasing frequency of exceptional weather conditions. We discuss the added value of large‐scale and long‐term population studies, but also emphasize the need to integrate more targeted experimental studies in the context of long‐term observational studies. For instance, in the case of the Glanville fritillary project, the long‐term study has produced an opportunity to sample individuals for experiments from local populations with a known demographic history. These studies have demonstrated striking differences in dispersal rate and other life‐history traits of individuals from newly established local populations (the offspring of colonizers) versus individuals from old, established local populations. The long‐term observational study has stimulated the development of metapopulation models and provided an opportunity to test model predictions. This combination of empirical studies and modeling has facilitated the study of key phenomena in spatial dynamics, such as extinction threshold and extinction debt.     

Cell‐specific changes in expression of mRNAs encoding splice variants of Aplysia cell adhesion molecule accompany long‐term synaptic plasticity

Aplysia neurons express several splice variants of apCAM, a member of the Ig superfamily of cell adhesion molecules. The major transmembrane isoform is endocytosed in sensory neurons (SNs) during the early phases of long‐term facilitation (LTF) of SN synapses evoked by serotonin (5‐HT) or in the motor neuron L7 during the early phases of long‐term depression (LTD) of SN synapses evoked by Phe‐Met‐Arg‐Phe‐amide (FMRFa). We used single cell RT‐PCR to evaluate whether expression of mRNAs encoding for different apCAM isoforms in SNs and L7 is regulated during LTF produced by 5‐HT, and LTD produced by FMRFa. Single SNs and L7s express mRNAs encoding for all major isoforms, but the proportion of each isoform expressed differs for the two cells. SN expresses more mRNA encoding for GPI‐linked isoforms, while L7 expresses more mRNA encoding for the major transmembrane isoform. The neuromodulators produced significant changes in the proportional levels of mRNAs encoding for specific apCAM isoforms during the first 4 h after treatments without affecting overall levels of apCAM mRNA. 5‐HT evoked changes that exaggerated cell‐specific differences in isoform expression. FMRFa evoked changes that reduced cell‐specific differences in isoform expression. The effects of the neuromodulators on apCAM mRNA expression were not detected when cells were cultured alone or when SNs were cocultured with another motor cell that failed to induce synapse formation (L11). The results suggest that rapid cell‐specific regulation of splice variant expression may contribute to different forms of long‐term synaptic plasticity. © 2000 John Wiley & Sons, Inc. J Neurobiol 45: 152–161, 2000     

α8‐Integrins are required for hippocampal long‐term potentiation but not for hippocampal‐dependent learning

Integrins are heterodimeric transmembrane cell adhesion receptors that are essential for a wide range of biological functions via cell–matrix and cell–cell interactions. Recent studies have provided evidence that some of the subunits in the integrin family are involved in synaptic and behavioral plasticity. To further understand the role of integrins in the mammalian central nervous system, we generated a postnatal forebrain and excitatory neuron‐specific knockout of α8‐integrin in the mouse. Behavioral studies showed that the mutant mice are normal in multiple hippocampal‐dependent learning tasks, including a T‐maze, non‐match‐to‐place working memory task for which other integrin subunits like α3‐ and β1‐integrin are required. In contrast, mice mutant for α8‐integrin exhibited a specific impairment of long‐term potentiation (LTP) at Schaffer collateral–CA1 synapses, whereas basal synaptic transmission, paired‐pulse facilitation and long‐term depression (LTD) remained unaffected. Because LTP is also impaired in the absence of α3‐integrin, our results indicate that multiple integrin molecules are required for the normal expression of LTP, and different integrins display distinct roles in behavioral and neurophysiological processes like synaptic plasticity.     

Relating fitness to long‐term environmental variations in natura

Quantifying links between ecological processes and adaptation dynamics in natura remains a crucial challenge. Many studies have documented the strength, form and direction of selection, and its variations in space and time, but only a few managed to link these variations to their proximal causes. This step is, however, crucial, if we are to understand how the variation in selective pressure affects adaptive allele dynamics in natural settings. We used data from a long‐term survey (about 30 years) monitoring the adaptation to insecticides of Culex pipiens mosquitoes in Montpellier area (France), focusing on three resistance alleles of the Ester locus. We used a population genetics model taking temporal and spatial variations in selective pressure into account, to assess the quantitative relationships between variations in the proximal agent of selection (amounts of insecticide sprayed) and the fitness of resistance alleles. The response to variations in selective pressure was fast, and the alleles displayed different fitness‐to‐environment relationships: the analyses revealed that even slight changes in insecticide doses could induce changes in the strength and direction of selection, thus changing the fitness ranking of the adaptive alleles. They also revealed that selective pressures other than the insecticides used for mosquito control affected the resistance allele dynamics. These fitness‐to‐environment relationships, fast responses and continuous evolution limit our ability to predict the outcome of adaptive allele dynamics in a changing environment, but they clearly contribute to the maintenance of polymorphism in natural populations. Our study also emphasizes the necessity of long‐term surveys in evolutionary ecology.     

Rapid bidirectional modulation of mRNA expression and export accompany long‐term facilitation and depression of Aplysia synapses

Serotonin (5‐HT) and the neuropeptide Phe‐Met‐Arg‐Phe‐amide (FMRFa) modulate synaptic efficacy of sensory neurons (SNs) of Aplysia in opposite directions and for long duration. Both long‐term responses require changes in mRNA and protein synthesis. The SN‐specific neuropeptide, sensorin A, is a gene product that appears to be increased by 5‐HT and decreased by FMRFa. We examined whether changes in sensorin A mRNA levels in the cell body and neurites of SNs accompany long‐term facilitation and depression. Both 5‐HT and FMRFa evoked rapid changes in sensorin A mRNA levels in the SN cell bodies: an increase with 5‐HT and a decrease with FMRFa. Parallel changes in sensorin A mRNA levels in SN neurites were detected 2 h and 4 h later. These rapid changes in mRNA expression and net export required the presence of the appropriate target motor cell L7. The neuromodulators failed to produce changes in mRNA expression or export when SNs were cultured alone or with the inappropriate target cell L11. The changes in mRNA expression were transient because mRNA levels returned to control values 24 h after treatment, while synaptic efficacy remained altered by the respective treatments. These results indicate that two neuromodulators produce distinct, but transient, target‐dependent effects on expression and export of a cell‐specific mRNA that correlate with changes in synaptic plasticity. © 2000 John Wiley & Sons, Inc. J Neurobiol 46: 41–47, 2001     

Modeling and empirical validation of long‐term carbon sequestration in forests (France, 1850–2015)

The development of appropriate tools to quantify long‐term carbon (C) budgets following forest transitions, that is, shifts from deforestation to afforestation, and to identify their drivers are key issues for forging sustainable land‐based climate‐change mitigation strategies. Here, we develop a new modeling approach, CRAFT (CaRbon Accumulation in ForesTs) based on widely available input data to study the C dynamics in French forests at the regional scale from 1850 to 2015. The model is composed of two interconnected modules which integrate biomass stocks and flows (Module 1) with litter and soil organic C (Module 2) and build upon previously established coupled climate‐vegetation models. Our model allows to develop a comprehensive understanding of forest C dynamics by systematically depicting the integrated impact of environmental changes and land use. Model outputs were compared to empirical data of C stocks in forest biomass and soils, available for recent decades from inventories, and to a long‐term simulation using a bookkeeping model. The CRAFT model reliably simulates the C dynamics during France's forest transition and reproduces C‐fluxes and stocks reported in the forest and soil inventories, in contrast to a widely used bookkeeping model which strictly only depicts C‐fluxes due to wood extraction. Model results show that like in several other industrialized countries, a sharp increase in forest biomass and SOC stocks resulted from forest area expansion and, especially after 1960, from tree growth resulting in vegetation thickening (on average 7.8 Mt C/year over the whole period). The difference between the bookkeeping model, 0.3 Mt C/year in 1850 and 21 Mt C/year in 2015, can be attributed to environmental and land management changes. The CRAFT model opens new grounds for better quantifying long‐term forest C dynamics and investigating the relative effects of land use, land management, and environmental change.     

Strong “bottom‐up” influences on small mammal populations: State‐space model analyses from long‐term studies

“Bottom‐up” influences, that is, masting, plus population density and climate, commonly influence woodland rodent demography. However, “top‐down” influences (predation) also intervene. Here, we assess the impacts of masting, climate, and density on rodent populations placed in the context of what is known about “top‐down” influences. To explain between‐year variations in bank vole Myodes glareolus and wood mouse Apodemus sylvaticus population demography, we applied a state‐space model to 33 years of catch‐mark‐release live‐trapping, winter temperature, and precise mast‐collection data. Experimental mast additions aided interpretation. Rodent numbers in European ash Fraxinus excelsior woodland were estimated (May/June, November/December). December–March mean minimum daily temperature represented winter severity. Total marked adult mice/voles (and juveniles in May/June) provided density indices validated against a model‐generated population estimate; this allowed estimation of the structure of a time‐series model and the demographic impacts of the climatic/biological variables. During two winters of insignificant fruit‐fall, 6.79 g/m² sterilized ash seed (as fruit) was distributed over an equivalent woodland similarly live‐trapped. September–March fruit‐fall strongly increased bank vole spring reproductive rate and winter and summer population growth rates; colder winters weakly reduced winter population growth. September–March fruit‐fall and warmer winters marginally increased wood mouse spring reproductive rate and September–December fruit‐fall weakly elevated summer population growth. Density dependence significantly reduced both species' population growth. Fruit‐fall impacts on demography still appeared after a year. Experimental ash fruit addition confirmed its positive influence on bank vole winter population growth with probable moderation by colder temperatures. The models show the strong impact of masting as a “bottom‐up” influence on rodent demography, emphasizing independent masting and weather influences; delayed effects of masting; and the importance of density dependence and its interaction with masting. We conclude that these rodents show strong “bottom‐up” and density‐dependent influences on demography moderated by winter temperature. “Top‐down” influences appear weak and need further investigation.     

Rethinking tropical phenology: insights from long‐term monitoring and novel analytical methods

Here, we introduce the Special Section (SS) on long‐term monitoring and new analytical methods in tropical phenology. The SS puts together nine original papers plus a synthesis, bringing significant advances and new insights into our understanding of tropical phenology across Africa and tropical America. The papers address environmental cues, methodological shortcomings, and provide innovative analytical approaches, opening new pathways, perspective and applications of tropical phenology for forest management and environmental monitoring. The SS is a substantial step toward a more comprehensive overview of trends in tropical phenology, as seven of nine studies evaluate >10‐yr data sets applying new methods of analysis such as hierarchical Bayesian models, generalized additive models, and Fourier analysis. We argue that it is essential to maintain ongoing monitoring programs and build a tropical phenology network at least for long‐term (>10 yr) study sites, providing the means for national and international financial support. Cross‐continental comparisons are now a primary goal, as we work toward a global vision of trends and shifts in tropical phenology in the Anthropocene.     

Avian ecological succession in the Amazon: A long‐term case study following experimental deforestation

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Long‐term ecological data for conservation: Range change in the black‐billed capercaillie (Tetrao urogalloides) in northeast China (1970s–2070s)

Long‐term ecological data can be an effective tool to help ecologists integrate future projections with historical contexts and provide unique insights into the long‐term dynamics of endangered species. However, hampered by data limitations, including incomplete and spatially biased data, relatively few studies have used multidecadal datasets or have examined changes in biogeography from a historical perspective. The black‐billed capercaillie (Tetrao urogalloides) is a large capercaillie (classified as Least Concern [LC] on the IUCN red list) that has undergone a dramatic decline in population during the late 20th century and is considered endangered. Its conservation status is pessimistic, and the species requires immediate protection. Therefore, we supplemented a historical dataset to identify changes in this bird's range and population in northeast China over the long term. The study area spanned Heilongjiang Province, Jilin Province, and the northeast corner of Inner Mongolia in northeast China. We integrated an ecological niche model (BIOMOD2) with long‐term ecological data on this species to estimate the magnitude of change in distribution over time. Our results revealed a 35.25% reduction in the current distribution of this species compared to their potential distribution in the 1970s. This decline is expected to continue under climate change. For example, the future range loss was estimated to be 38.79 ± 0.22% (8.64–90.19%), and the actual state could be worse, because the baseline range of the model was greater than the real range in the 2000s, showing a 12.39% overestimation. To overcome this poor outlook, a conservation strategy should be established in sensitive areas, including the southwestern Greater Khingan Mountains and northern Lesser Khingan Mountains. Actions that should be considered include field investigations, establishing a monitor network, designing ecological corridors, and cooperating with local inhabitants, governments, and conservation biologists to improve the conservation of the black‐billed capercaillie.     

Oral health care in long‐term care facilities for elderly people in southern Brazil: a conceptual framework

doi:10.1111/j.1741‐2358.2009.00280.x
Oral health care in long‐term care facilities for elderly people in southern Brazil: a conceptual framework Objective: To present a theoretical model for understanding oral health care for the elderly in the context of long‐term care institutions (LTCI). Methods: Open‐ended individual interviews were conducted with the elderly residing in LTCI, their carers, nursing technicians and nurses, directors of care, dental surgeons and managers of public health services. A grounded theory methodological approach was adopted for data collection and analysis. Results: The emerging core category revealed a basic social process: ‘Promoting oral health care for the elderly based on the context of LTCI’. This process was composed of two contradicting yet correlated aspects: the oral health care does not minimise the poor oral epidemiological condition, and at the same time, there was a continued improvement in the oral care expressed by better care practices. These aspects were related to the: attribution of meaning to oral health, social determination of oral health, the ageing process, interactions established in the oral health care practices, oral health care management in LTCI, inclusion of oral health care into the political–organisational dimension and possibility of conjecturing better oral health care practices. Conclusion: The core concept of ‘Promotion of oral health care for elderly people based on the context of LTCI’ is capable of explaining the variations in the structure and process of LTCI, as well as in helping to understand the meaning of the oral health care practices for the institutionalised elderly.