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1.
iScience ; 27(3): 109036, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38361612

RESUMO

Among the most important impacts of biological invasions on biodiversity is biotic homogenization, which may further compromise key ecosystem processes. However, the extent to which they homogenize functional diversity and shift dominant ecological strategies of invaded communities remains uncertain. Here, we investigated changes in plant communities in a northern North American forest in response to invasive earthworms, by examining the taxonomic and functional diversity of the plant community and soil ecosystem functions. We found that although plant taxonomic diversity did not change in response to invasive earthworms, they modified the dominance structure of plant functional groups. Invasive earthworms promoted the dominance of fast-growing plants at the expense of slow-growing ones. Moreover, earthworms decreased plant functional diversity, which coincided with changes in abiotic and biotic soil properties. Our study reveals that invasive earthworms erode multiple biodiversity facets of invaded forests, with potential cascading effects on ecosystem functioning.

2.
Addict Behav Rep ; 16: 100437, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35694108

RESUMO

Given prevalent alcohol misuse-emotional comorbidities among young adults, we developed an internet-based integrated treatment called Take Care of Me. Although the treatment had an impact on several secondary outcomes, effects were not observed for the primary outcome. Therefore, the goal of the current study was to examine heterogeneity in treatment responses. The initial RCT randomized participants to either a treatment or psychoeducational control condition. We conducted an exploratory latent class analysis to distinguish individuals based on pre-treatment risk and then used moderated regressions to examine differential treatment responses based on class membership. We found evidence for three distinct groups. Most participants fell in the "low severity" group (n = 123), followed by the "moderate severity" group (n = 57) who had a higher likelihood of endorsing a previous mental health diagnosis and treatment and higher symptom severity than the low group. The "high severity" group (n = 42) endorsed a family history of alcoholism, and the highest symptom severity and executive dysfunction. Moderated regressions revealed significant class differences in treatment responses. In the treatment condition, high severity (relative to low) participants reported higher alcohol consumption and hazardous drinking and lower quality of life at follow-up, whereas moderate severity (relative to low) individuals had lower alcohol consumption at follow-up, and lower hazardous drinking at end-of-treatment. No class differences were found for participants in the control group. Higher risk individuals in the treatment condition had poorer responses to the program. Tailoring interventions to severity may be important to examine in future research.

3.
Biol Lett ; 18(3): 20210636, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35350876

RESUMO

Declining arthropod communities have recently gained a lot of attention, with climate and land-use change among the most frequently discussed drivers. Here, we focus on a seemingly underrepresented driver of arthropod community decline: biological invasions. For approximately 12 000 years, earthworms have been absent from wide parts of northern North America, but they have been re-introduced with dramatic consequences. Most studies investigating earthworm-invasion impacts focus on the belowground world, resulting in limited knowledge on aboveground-community changes. We present observational data on earthworm, plant and aboveground arthropod communities in 60 plots, distributed across areas with increasing invasion status (low, medium and high) in a Canadian forest. We analysed how earthworm-invasion status and biomass impact aboveground arthropod community abundance, biomass and species richness, and how earthworm impacts cascade across trophic levels. We sampled approximately 13 000 arthropods, dominated by Hemiptera, Diptera, Araneae, Thysanoptera and Hymenoptera. Total arthropod abundance, biomass and species richness declined significantly from areas of low to those with high invasion status, with reductions of 61, 27 and 18%, respectively. Structural equation models suggest that earthworms directly and indirectly impact arthropods across trophic levels. We show that earthworm invasion can alter aboveground multi-trophic arthropod communities and suggest that belowground invasions might be underappreciated drivers of aboveground arthropod decline.


Assuntos
Artrópodes , Oligoquetos , Animais , Canadá , Florestas , Plantas
4.
Subst Use Misuse ; 57(1): 96-104, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34753393

RESUMO

Background: Emerging adulthood is associated with heavy drinking. Despite overall heavy use, studies show considerable heterogeneity in emerging adult drinking habits. Lau-Barraco and colleagues (2016 b) identified three subtypes (high, moderate, low) of emerging adult heavy drinkers based on patterns of use across common drinking situations. Heavy situational drinkers had more alcohol problems, mental health symptoms, and coping/conformity motives for alcohol use.Objective: Our goal was to replicate and extend the aforementioned study, expecting to find the same subgroups, then examining whether certain risk factors predicted subgroup membership.Methods/Results: Undergraduates (N = 497) completed online self-report measures and a latent profile analysis (LPA) found support for three similar subtypes; low, "moderate" (higher endorsement of pleasant emotion/social pressure situations, relative to the low group), and high. Univariate ANOVAs, followed by pairwise comparisons, found that heavy situational drinkers scored highest on measures of alcohol problems, problem gambling, drug use, depression, and anxiety compared to the other two groups, and consistent with previous findings.Conclusions: This study showed that emerging adults who drink heavily across various situations are likely to engage in other addictive behaviors and struggle with mental health symptoms. Identifying one's personal risk factors and their riskiest drinking situations is critical for developing targeted intervention programs and increasing the understanding of the heterogeneous nature of drinking behaviors in emerging adults in Canada.


Assuntos
Consumo de Bebidas Alcoólicas , Transtornos Relacionados ao Uso de Álcool , Adaptação Psicológica , Adulto , Consumo de Bebidas Alcoólicas/psicologia , Humanos , Motivação , Comportamento Social , Estudantes/psicologia
5.
Addict Behav Rep ; 14: 100390, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34938848

RESUMO

Many young adults struggle with comorbid alcohol misuse and emotional problems (i.e., depression and anxiety). However, there is currently a paucity of evidence-based, integrated, accessible treatment options for individuals with these comorbidities. The main goal of this study was to examine efficacy of a novel online, minimally guided, integrated program for comorbid alcohol misuse and emotional problems in young adults. Method: The study was an open-label two-arm RCT. Participants (N = 222, M age = 24.6, 67.6% female) were randomized to one of two conditions: the Take Care of Me program (an 8-week, online integrated treatment condition consisting of 12 modules), or an online psychoeducational control condition. Intervention modules incorporated content based on principles of cognitive behavioral therapy and motivational interviewing. Participants completed assessment data at baseline, at the end of treatment (i.e., 8 weeks), and at follow-up (i.e., 24 weeks). Data were analyzed using generalized linear mixed models. Results: We observed that participants in the treatment condition showed larger reductions in depression, hazardous drinking, as well as increases in psychological quality of life and confidence at the end of treatment. We did not find group differences on total alcohol use at follow-up, but participants in the treatment group reduced their hazardous drinking and improved their quality of life at 24-week follow-up. Conclusions: Our study provides promising initial evidence for the first iteration of the comorbid alcohol misuse and emotional problems online program.

6.
Pediatr Qual Saf ; 6(5): e473, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34589647

RESUMO

Improving the discharge process is an area of focus throughout healthcare organizations. Capacity constraints, efficiency improvement, patient safety, and quality care are driving forces for many discharge process workgroups. METHODS: Following the Pareto principle, we focused on improving the discharge process on the medical-surgical units that received the most patients admitted from the emergency department. Increased demand for medical-surgical beds, renovations, and diminished bed capacity made it imperative to improve efficiency using quality improvement techniques. A core team of frontline staff decreased the time between computer entry of discharge orders and patient's departure from the unit to less than 60 minutes, with 80% compliance. The team developed a daily dashboard that detailed the process and outcome measures to create situational awareness and daily visual management. Additional observations of staff workflow uncovered excessive walking for printer use. Printers were placed at the point of use to reduce transport times. Next, using survey results provided by patients on discharge quality, a Treasure Map that aided with teach-back and Team Discharge were implemented to level the staff's workload. Finally, physicians discharged patients earlier in the day. They standardized their discharge criteria to remove subjectivity from the discharge process and enable better team involvement. RESULTS: After implementing 4 interventions, the average time between computer entry of discharge orders and patient's departure from the unit decreased (94.26 versus 65.98 minutes; P < 0.001), simultaneously reducing our average length of stay from 5.62 to 4.81 days (P < 0.001). CONCLUSIONS: In conclusion, hardwiring proven interventions and complementing them with daily visual management led to significant, sustained results.

7.
Subst Use Misuse ; 56(11): 1715-1725, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34253147

RESUMO

INTRODUCTION: Depression and problem drinking are comorbid in emerging adulthood, yet the processes that link them are not well understood. Research has argued that shame has a unique influence on the experience of problematic drinking, but this has rarely been assessed at the state level. Using ecological momentary assessments (EMAs), we assessed whether shame, and not guilt, mediated the association between baseline depression and alcohol use and problems. METHODS: One hundred and eighty-four emerging adults (Mage= 19.27) completed a 12-day EMA study. Multilevel models were used to test hypotheses. RESULTS: In a model with alcohol use as the outcome, there were no significant associations between shame or guilt and alcohol use at the within- or between-subjects level. In a model with alcohol problems as the outcome, guilt was positively associated with alcohol problems but only at the daily level. At the between-subjects level and after controlling for guilt, there was a significant association between depression, shame, and alcohol problems; average levels of shame mediated the association between depression and alcohol problems. In post-hoc reverse directionality models, average alcohol problems mediated the relationship between depression and shame and guilt at the between-person level. No mediation was present for alcohol use. CONCLUSION: After controlling for guilt, shame is an emotion that helps explain risk for alcohol problems among depressed emerging adults, which has implications for targeted interventions. Reciprocal associations between shame, guilt, and alcohol problems emerged highlighting the need for more fulsome assessments of shame and guilt in future EMA research.


Assuntos
Alcoolismo , Depressão , Adulto , Depressão/epidemiologia , Emoções , Culpa , Humanos , Vergonha , Adulto Jovem
9.
Alcohol Alcohol ; 55(5): 540-546, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32599612

RESUMO

AIMS: Comorbid alcohol use and depression have the highest prevalence among emerging adults and are associated with a number of consequences. Self-medication theory posits individuals with depression use alcohol to cope with their negative emotions. Preliminary work has investigated the social context of depression-related drinking and found that solitary drinking is a risky, atypical behaviour in emerging adulthood that is associated with alcohol misuse. However, it is unknown about what is unfolding in the moment that is driving depression-related drinking in solitary contexts. Accordingly, we used an experimental study to examine if shame mediated the association between depression and in-lab alcohol craving. METHODS: Emerging adults (N = 80) completed a shame induction followed by an alcohol cue exposure in either a solitary or social condition. We used moderated mediation to test hypotheses. RESULTS: Consistent with hypotheses, conditional indirect effects supported the mediation of depression and alcohol craving through shame among those in the solitary condition, but not in the social condition. There was no support for guilt as a mediator. CONCLUSION: Our study demonstrates that shame is a specific emotional experience that contributes to solitary drinking among depressed emerging adults. It is important to use these results to inform interventions that directly target solitary contexts and shame.


Assuntos
Consumo de Bebidas Alcoólicas/psicologia , Fissura , Depressão/complicações , Depressão/psicologia , Solidão , Vergonha , Adolescente , Adulto , Feminino , Culpa , Humanos , Masculino , Fatores de Risco , Interação Social , Estudantes , Inquéritos e Questionários , Adulto Jovem
10.
Ecol Evol ; 10(3): 1510-1525, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32076530

RESUMO

The leaf economic traits such as leaf area, maximum carbon assimilation rate, and venation are all correlated and related to water availability. Furthermore, leaves are often broad and large in humid areas and narrower in arid/semiarid and hot and cold areas. We use optimization theory to explain these patterns. We have created a constrained optimization leaf model linking leaf shape to vein structure that is integrated into coupled transpiration and carbon assimilation processes. The model maximizes net leaf carbon gain (NPPleaf) over the loss of xylem water potential. Modeled relations between leaf traits are consistent with empirically observed patterns. As the results of the leaf shape-venation relation, our model further predicts that a broadleaf has overall higher NPPleaf compared to a narrowleaf. In addition, a broadleaf has a lower stomatal resistance compared to a narrowleaf under the same level of constraint. With the same leaf area, a broadleaf will have, on average, larger conduits and lower total leaf xylem resistance and thus be more efficient in water transportation but less resistant to cavitation. By linking venation structure to leaf shape and using water potential as the constraint, our model provides a physical explanation for the general pattern of the covariance of leaf traits through the safety-efficiency trade-off of leaf hydraulic design.

11.
Addict Behav ; 92: 115-121, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30612020

RESUMO

Problem drinking and gambling are addictive behaviours experienced by young adults and commonly occur with narcissism. Research has acknowledged two distinct forms of narcissism: grandiose and vulnerable. There has been work that has examined the relationship between grandiose and vulnerable narcissism and addictive behaviours, but it has been limited, particularly with vulnerable narcissism. Evidence suggests vulnerable narcissism, but not grandiose narcissism, is associated with greater negative affect. Accordingly, shame, a potent social emotion could be a mediator in the narcissism-addiction pathway. Shame has been implicated in both vulnerable narcissism and problem drinking and gambling. Thus, we hypothesized that shame would mediate the relationship between vulnerable narcissism and addictive behaviours. Young adults (N = 210) completed self-report baseline (Time 1) and 1-month follow-up (Time 2) assessments of shame, narcissism, problem drinking, and gambling. As predicted, those with elevated vulnerable narcissism at Time 1 had increased shame at Time 2, which predicted problem drinking and gambling at Time 2. This relationship was not observed for grandiose narcissism. Overall, our results suggest that feelings of shame are essential to understanding the vulnerable narcissism-addiction pathway, and an important consideration when designing clinical interventions for at-risk young adults.


Assuntos
Alcoolismo/epidemiologia , Comportamento Aditivo/epidemiologia , Comportamento Aditivo/psicologia , Jogo de Azar/epidemiologia , Narcisismo , Vergonha , Adulto , Alcoolismo/psicologia , Comorbidade , Feminino , Seguimentos , Jogo de Azar/psicologia , Humanos , Estudos Longitudinais , Masculino , Manitoba/epidemiologia , Autorrelato , Estudantes/psicologia , Universidades , Adulto Jovem
12.
JMIR Res Protoc ; 7(11): e11298, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30389649

RESUMO

BACKGROUND: Alcohol misuse and emotional problems (ie, depression and anxiety) are highly comorbid among Canadian young adults. However, there is a lack of integrated, accessible, and evidence-based treatment options for these young adults. OBJECTIVE: The main goal of this study is to develop and test the efficacy of an integrated, online self-help program designed to target both alcohol misuse and emotional problems. METHODS: A two-arm randomized controlled trial design will be used to compare the efficacy of the online integrated treatment to a psychoeducational control group. A target sample of 214 participants will be recruited and randomly assigned to either condition. The integrated treatment will last 8 weeks, and participants will work through 12 modules. Modules will incorporate content based on principles of cognitive behavioral therapy and motivational interviewing. Participants in the control group will receive links to psychoeducational resources and will have access to the full treatment after follow-up. The primary outcome will be the number of Canadian standard drinks consumed in the week leading up the assessment. Secondary outcomes of interest include symptoms of depression, anxiety, alcohol-related problems, quality of life, and use of other drugs. Assessments will be completed at 3 time-points: at baseline, at the end of treatment (ie, 8 weeks), and at follow-up (ie, 24 weeks). Upon completion, data will be analyzed using generalized linear mixed models. RESULTS: Data collection began in June 2018 and will continue until January 2020. Final study results will be submitted for publication by July 2020. CONCLUSIONS: Currently, there are no integrated treatments designed to target alcohol misuse and the range of emotional problems experienced by young adults. This research stands to provide an effective, accessible (ie, Web-based), and feasible option to treat the many struggling young adults in this country. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT03406039; https://clinicaltrials.gov/ct2/show/NCT03406039 (Archived by WebCite at http://www.webcitation.org/72fDefnrh). REGISTERED REPORT IDENTIFIER: PRR1-10.2196/11298.

13.
Addict Behav ; 82: 94-100, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29505986

RESUMO

BACKGROUND: Alcohol and gambling problems are common in young adults. Self-medication theory states that young adults with depression drink and/or gamble to escape negative emotions. Research shows that depression is a risk factor for drinking/gambling problems, but more work is needed to examine mediators underlying these associations. One potential mediator is shame. Shame is a self-directed emotion that follows a negative life event and is characterized by intense feelings of inferiority, worthlessness, and embarrassment. Depressed individuals are especially susceptible to shame (and associated emotions). Shame has also been implicated in risk for addiction. Accordingly, we predicted that elevated shame would explain why depression is associated with both alcohol and gambling problems. METHODS: A longitudinal design was used to examine this hypothesis. Undergraduates (N = 210) completed self-reports of depression at baseline (Time 1) and then completed self-reports of shame, alcohol misuse, gambling problems one month later (Time 2). RESULTS: Results showed that individuals with elevated depression at Time 1 endorsed high levels of shame at Time 2, which in turn predicted more gambling (ß = .038, 95% CI [.010, .087]) and alcohol problems (ß = .249, 95% CI [.123, .435]) at Time 2. We found that increased levels of shame explained the effects of depression on problem drinking and gambling. CONCLUSIONS: Study findings improve our understanding of the depressive pathway to addiction by providing evidence for shame as a potential mechanism of this pathway. IMPACT: Reducing shame can be a target of clinical interventions for young adults with depression and alcohol/gambling problems.


Assuntos
Comportamento Aditivo/psicologia , Transtorno Depressivo/psicologia , Vergonha , Alcoolismo/psicologia , Correlação de Dados , Feminino , Jogo de Azar/psicologia , Humanos , Estudos Longitudinais , Masculino , Manitoba , Autorrelato , Adulto Jovem
14.
J Pers ; 84(5): 685-96, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26179679

RESUMO

Research on narcissism and envy suggests a variable relationship that may reflect differences between how vulnerable and grandiose narcissism relate to precursors of envy. Accordingly, we proposed a model in which dispositional envy and relative deprivation differentially mediate envy's association with narcissistic vulnerability, grandiosity, and entitlement. To test the model, 330 young adults completed dispositional measures of narcissism, entitlement, and envy; one week later, participants reported on deprivation and envy feelings toward a peer who outperformed others on an intelligence test for a cash prize (Study 1) or earned higher monetary payouts in a betting game (Study 2). In both studies, structural equation modeling broadly supported the proposed model. Vulnerable narcissism robustly predicted episodic envy via dispositional envy. Entitlement-a narcissistic facet common to grandiosity and vulnerability-was a significant indirect predictor via relative deprivation. Study 2 also found that (a) the grandiose leadership/authority facet indirectly curbed envy feelings via dispositional envy, and (b) episodic envy contributed to schadenfreude feelings, which promoted efforts to sabotage a successful rival. Whereas vulnerable narcissists appear dispositionally envy-prone, grandiose narcissists may be dispositionally protected. Both, however, are susceptible to envy through entitlement when relative deprivation is encountered.


Assuntos
Relações Interpessoais , Narcisismo , Personalidade , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
15.
Arch Suicide Res ; 19(2): 202-17, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25559346

RESUMO

The purpose of this study is to investigate whether the type and number of stressful life events (SLEs) will be associated with suicidal behavior in a 3-year follow-up period in persons with major depressive disorder (MDD). Data came from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a nationally representative longitudinal survey of mental health in non-institutionalized adults in the United States. The survey consisted of two waves: Wave 1 (2001--2002) and Wave 2 (2004-2005), n = 34,653. Twelve past-year SLEs were assessed at baseline. These SLEs were categorized into the following groups based on previous research: Loss or victimization; Relationship, friendship, or interpersonal stress; Financial stress; and Legal problems. Only respondents with MDD at Wave 1 were included (n = 6,004). Several SLEs were strongly associated with suicide attempts, among which, "serious problems with neighbor, friend, or relative" (adjusted odds ratio [AOR] = 2.21; 95% confidence interval [95% CI]: 1.41, 3.45) and "major financial crisis, bankruptcy, or unable to pay bills" (AOR = 2.31; 95% CI: 1.45, 3.66) were the most robust predictors of suicide attempts even after adjusting for sociodemographic variables and any anxiety, substance use, or personality disorder. People with MDD who had been exposed to certain SLEs are at elevated risk for future suicide attempts, even after accounting for the demographic factors and psychiatric comorbidity.


Assuntos
Acontecimentos que Mudam a Vida , Saúde Mental/estatística & dados numéricos , Transtornos Relacionados ao Uso de Substâncias , Tentativa de Suicídio , Adulto , Canadá/epidemiologia , Comorbidade , Transtorno Depressivo Maior/epidemiologia , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Fatores Socioeconômicos , Estatística como Assunto , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Ideação Suicida , Tentativa de Suicídio/prevenção & controle , Tentativa de Suicídio/psicologia , Tentativa de Suicídio/estatística & dados numéricos , Inquéritos e Questionários
16.
Proc Natl Acad Sci U S A ; 110(20): 8117-22, 2013 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-23569221

RESUMO

Forests are expected to expand into alpine areas because of climate warming, causing land-cover change and fragmentation of alpine habitats. However, this expansion will only occur if the present upper treeline is limited by low-growing season temperatures that reduce plant growth. This temperature limitation has not been quantified at a landscape scale. Here, we show that temperature alone cannot realistically explain high-elevation tree cover over a >100-km(2) area in the Canadian Rockies and that geologic/geomorphic processes are fundamental to understanding the heterogeneous landscape distribution of trees. Furthermore, upslope tree advance in a warmer scenario will be severely limited by availability of sites with adequate geomorphic/topographic characteristics. Our results imply that landscape-to-regional scale projections of warming-induced, high-elevation forest advance into alpine areas should not be based solely on temperature-sensitive, site-specific upper-treeline studies but also on geomorphic processes that control tree occurrence at long (centuries/millennia) timescales.


Assuntos
Geografia , Árvores/crescimento & desenvolvimento , Canadá , Clima , Mudança Climática , Ecologia , Ecossistema , Geologia , Modelos Teóricos , Estações do Ano , Temperatura
17.
Ann N Y Acad Sci ; 1249: 151-65, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22243366

RESUMO

Because of its generally low density of humans and few settlements, the circumpolar boreal forest is often viewed as an untouched wilderness. However, archeological evidence indicates that humans have inhabited the region since the continental glaciers disappeared 8,000-12,000 years ago. This paper discusses the ecological impacts that humans have had on the boreal forest ecosystem through their activities in prehistoric, historic, and recent times and argues that the boreal forest has always been a cultural landscape with a gradient of impacts both spatially and temporally. These activities include hunting, trapping, herding, agriculture, forestry, hydroelectric dam projects, oil and natural gas development, and mining. In prehistoric times, human impacts would generally have been more temporary and spatially localized. However, the megafaunal extinctions coincident with arrival of humans were very significant ecological impacts. In historic times, the spread of Europeans and their exploitation of the boreal's natural resources as well as agricultural expansion has altered the composition and continuity of the boreal forest ecosystem in North America, Fennoscandia, and Asia. Particularly over the last century, these impacts have increased significantly (e.g., some hydroelectric dams and tar sands developments that have altered and destroyed vast areas of the boreal forest). Although the atmospheric changes and resulting climatic changes due to human activities are causing the most significant changes to the high-latitude boreal forest ecosystem, any discussion of these impacts are beyond the limits of this paper and therefore are not included.


Assuntos
Ecossistema , Árvores , Agricultura/história , Criação de Animais Domésticos/história , Animais , Fontes Geradoras de Energia , Meio Ambiente , Agricultura Florestal/história , Geografia , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , História Antiga , História Medieval , Humanos , América do Norte
18.
Ecol Lett ; 11(5): 419-31, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18341585

RESUMO

Many introductory ecology textbooks illustrate succession, at least in part, by using certain classic studies (e.g. sand dunes, ponds/bogs, glacial till, and old fields) that substituted space for time (chronosequence) in determining the sequences of the succession. Despite past criticisms of this method, there is continued, often uncritical, use of chronosequences in current research on topics besides succession, including temporal changes in biodiversity, productivity, nutrient cycling, etc. To show the problem with chronosequence-based studies in general, we review evidence from studies that used non-chronosequence methods (such as long-term study of permanent plots, palynology, and stand reconstruction) to test the space-for-time substitution in four classic succession studies. In several cases, the tests have used the same locations and, in one case, the same plots as those in the original studies. We show that empirical evidence invalidates the chronosequence-based sequences inferred in these classic studies.


Assuntos
Ecossistema , Tempo
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