Mangroves are one of the most carbon‐dense forests on the Earth and have been highlighted as key ecosystems for climate change mitigation and adaptation. Hundreds of studies have investigated how ...mangroves fix, transform, store, and export carbon. Here, we review and synthesize the previously known and emerging carbon pathways in mangroves, including gains (woody biomass accumulation, deadwood accumulation, soil carbon sequestration, root and litterfall production), transformations (food web transfer through herbivory, decomposition), and losses (respiration as CO2 and CH4, litterfall export, particulate and dissolved carbon export). We then review the technologies available to measure carbon fluxes in mangroves, their potential, and their limitations. We also synthesize and compare mangrove net ecosystem productivity (NEP) with terrestrial forests. Finally, we update global estimates of carbon fluxes with the most current values of fluxes and global mangrove area. We found that the contributions of recently investigated fluxes, such as soil respiration as CH4, are minor (<1 Tg C year−1), while the contributions of deadwood accumulation, herbivory, and lateral export are significant (>35 Tg C year−1). Dissolved inorganic carbon exports are an order of magnitude higher than the other processes investigated and were highly variable, highlighting the need for further studies. Gross primary productivity (GPP) and ecosystem respiration (ER) per area of mangroves were within the same order of magnitude as terrestrial forests. However, ER/GPP was lower in mangroves, explaining their higher carbon sequestration. We estimate the global mean mangrove NEP of 109.1 Tg C year−1 (7.4 Mg C ha−1 year−1) or through a budget balance, accounting for lateral losses, a global mean of 66.6 Tg C year−1 (4.5 Mg C ha−1 year−1). Overall, mangroves are highly productive, and despite losses due to respiration and tidal exchange, they are significant carbon sinks.
The status and potential degradation of an ecosystem is often difficult to identify, quantify, and characterize. Multiple, concurrent drivers of degradation may interact and have cumulative and ...confounding effects, making mitigation and rehabilitation actions challenging to achieve. Ecosystem status assessments generally emphasize areal change (gains/losses) as a primary indicator; however, this over-simplifies complex ecosystem dynamics and ignores metrics that would better assess ecosystem quality. Consideration of multiple indicators is necessary to characterize and/or anticipate ecosystem degradation and appropriately identify factors causing changes. We utilize mangrove forests as a model system due to their distribution across a wide range of geographic settings, their position in the inherently dynamic coastal zone, and the multiple natural and anthropogenic pressures they face. We present a conceptual framework to: i) examine drivers of ecosystem degradation and characterize system status, and ii) delineate the roles of biogeographic and geomorphic variability, site history and typology, and references. A complementary workflow is proposed for implementing the conceptual framework. We demonstrate the universal applicability of our conceptual framework through a series of case studies that represent locations with differing drivers of degradation and biogeographic and geomorphic conditions. Our conceptual framework facilitates scientists, conservation practitioners, and other stakeholders in considering multiple aspects of ecosystems to better assess system status and holistically evaluate degradation. This is achieved by critically evaluating suitable comparisons and relevant elements in assessing a site to understand potential actions or the outcome of previously implemented management strategies.
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•Assessing degradation can be improved by understanding both drivers of degradation and overall system status•We provide a framework that compares indicators of degradation and system status using mangrove forests as a model system•The framework was applied to six global locations showcasing it’s flexibility to utilize existing data from varied sources•The conceptual framework can inform scientists, practitioners, and other stakeholders as they monitor and manage their system
Climate change is altering species’ range limits and transforming ecosystems. For example, warming temperatures are leading to the range expansion of tropical, cold-sensitive species at the expense ...of their cold-tolerant counterparts. In some temperate and subtropical coastal wetlands, warming winters are enabling mangrove forest encroachment into salt marsh, which is a major regime shift that has significant ecological and societal ramifications. Here, we synthesized existing data and expert knowledge to assess the distribution of mangroves near rapidly changing range limits in the southeastern USA. We used expert elicitation to identify data limitations and highlight knowledge gaps for advancing understanding of past, current, and future range dynamics. Mangroves near poleward range limits are often shorter, wider, and more shrublike compared to their tropical counterparts that grow as tall forests in freeze-free, resource-rich environments. The northern range limits of mangroves in the southeastern USA are particularly dynamic and climate sensitive due to abundance of suitable coastal wetland habitat and the exposure of mangroves to winter temperature extremes that are much colder than comparable range limits on other continents. Thus, there is need for methodological refinements and improved spatiotemporal data regarding changes in mangrove structure and abundance near northern range limits in the southeastern USA. Advancing understanding of rapidly changing range limits is critical for foundation plant species such as mangroves, as it provides a basis for anticipating and preparing for the cascading effects of climate-induced species redistribution on ecosystems and the human communities that depend on their ecosystem services.
Since the discovery of ammonia-oxidizing archaea (AOA), new questions have arisen about population and community dynamics and potential interactions between AOA and ammonia-oxidizing bacteria (AOB). ...We investigated the effects of long-term fertilization on AOA and AOB in the Great Sippewissett Marsh, Falmouth, MA, USA to address some of these questions. Sediment samples were collected from low and high marsh habitats in July 2009 from replicate plots that received low (LF), high (HF), and extra high (XF) levels of a mixed NPK fertilizer biweekly during the growing season since 1974. Additional untreated plots were included as controls (C). Terminal restriction fragment length polymorphism analysis of the amoA genes revealed distinct shifts in AOB communities related to fertilization treatment, but the response patterns of AOA were less consistent. Four AOB operational taxonomic units (OTUs) predictably and significantly responded to fertilization, but only one AOA OTU showed a significant pattern. Betaproteobacterial amoA gene sequences within the Nitrosospira-like cluster dominated at C and LF sites, while sequences related to Nitrosomonas spp. dominated at HF and XF sites. We identified some clusters of AOA sequences recovered primarily from high fertilization regimes, but other clusters consisted of sequences recovered from all fertilization treatments, suggesting greater physiological diversity. Surprisingly, fertilization appeared to have little impact on abundance of AOA or AOB. In summary, our data reveal striking patterns for AOA and AOB in response to long-term fertilization, and also suggest a missing link between community composition and abundance and nitrogen processing in the marsh.
Based on interviews with 120 children ranging from age 3 to 12, legal interviewers rated the grade school and middle school age children as competent and as understanding the meaning of lying. The ...interviewers rated the grade school children as more credible 'witnesses in court' than either the preschool or the middle school age children. The cues they reported using most frequently were affect and eye contact.
Interaction coaching was given to 44 depressed mothers who had either a withdrawn or intrusive interaction style with their infants. The intrusive and withdrawn mothers were given instructions either ...to imitate their infants' behavior or to keep their infants' attention. The results suggested that the specific type of interaction coaching for the specific type of depressed mother (imitation for the intrusive mothers and attention‐getting for the withdrawn mothers) significantly improved their interaction behaviors with their infants.
Groups of noninstitutionalized organic and familial mentally retarded and borderline mentally retarded children at two CA levels were given tasks designed to assess imitation. In contrast to findings ...from studies of average IQ children, organic low IQ children showed as much imitativeness at the older as at the younger age levels. Consistent with expectations, etiology, independent of IQ, was found to be significant. Familial low IQ children showed more absolute imitation and recall, whereas organic children were more imitative and responsive to the irrelevant behaviors modeled. Findings are discussed in terms of the developmental approach to imitation.
8 groups of 24 children, institutionalized and noninstitutionalized, familial and organic retarded, and younger and older normal children, were given 2 measures of outerdirectedness. 1 was a 3-choice ...discrimination learning task in which a light was presented above 1 of the 2 incorrect stimuli; the 2nd was a task in which the child could imitate designs made by an adult or presented by a machine. The 4 retarded groups were found to be more outerdirected (i.e., selected the erroneous cued stimulus and imitated more often) than the 4 normalgroups. The younger noninstitutionalized normal Ss were found to be more imitative than the older normal Ss. Institutionalization for both normal and retarded Ss and the etiology of retardation were also found to be related to degree of outerdirectedness.
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CEKLJ, FFLJ, NUK, ODKLJ, PEFLJ
4 groups of 48 children, institutionalized and noninstitutionalized younger and older children of normal intelligence, were administered a measure of outerdirectedness. The task, which was designed ...to elicit imitative behavior, allowed for the comparison of performance under conditions where (a) the task was presented as a problem or no problem, and (b) cues were provided by an adult or by a machine. Younger children were found to be more imitative than older children. More imitation was found in the machine-cue than in the adult-cue condition. Younger noninstitutionalized children were found to be more imitative than younger institutionalized children, but only if the task did not require the solution of a problem. The relationship of these findings to reinforcement and contiguity-mediational theories of imitation was discussed.
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