economically and ecologically valuable, are lowered and recovery is hampered (Hoegh- Guldberg et al. 2007).
Since a high spatial variability in reef condition on a regional scale was observed for the reefs of the Thousand Islands due to more localized rather than regional stressors, this has to be considered in future conservation and management plans. Marine spatial planning that is adjusted to local conditions and takes into consideration the different spatial scales on which stressors and resource uses interact with reef communities (Sale et al. 2014) is an alternative to current management strategies (i.e. marine protected- and no-take areas (MPA’s and NTA’s; see Hoegh-Guldberg et al. 2007, Douvere 2008, Wilson et al. 2010). In addition, monitoring key biological and environmental parameters continuously over several years and across seasons is crucial for the establishment of successful management and conservation plans. Besides these reef management strategies, the involvement of local communities into reef protection is needed (Inglehart 1995, Ferse et al. 2010). Marine awareness and local education campaigns could aid the enforcement of protection areas and, for instance, help to change the washing habits of local fishermen and reduce WAF-D and LAS pollution in the region. Any conservation and management plan, however, will only be successful if pollution in Jakarta is reduced, e.g. by implementing sewage treatment and waste disposal plans (Clara et al. 2007, Rebello et al. 2014). In Indonesia, as in most adjacent countries in South-East Asia, treatment of sewage is still largely missing (Burke et al. 2012). Reducing environmental exposure by anthropogenicstressors, i.e. the initial cause of vulnerability of costal communities, will improve livelihoods of people (Ferrol-Schulte et al. 2015). Nevertheless, without a better understanding of impacts of combined stressors on marine organisms and underlying mechanisms (Knowlton and Jackson 2008), these mitigation efforts and management strategies such as marine planning and conservation are however void in the end.
Low inferred avgVWHO for the 1850s may be attributed to increased settlement and human activities in the Lake Erie watershed at that time, which included anthropogenicstressors such as deforestation, wetland draining, increased farmland cover and population (Hatcher 1971; Burns 1985; Chapter 3). Fossil diatom records indicate that during this time period there were higher nutrient levels, as there was a shift towards more eutrophic diatom taxa, such as Stephanodiscus and Fragilaria (Harris and Vollenweider 1982; Stoermer et al. 1987; Stoermer et al. 1996; Allinger and Reavie 2013). However, while nutrient inputs and the associated shifts towards more eutrophic diatom continued between 1850s-1860s, there was an increase in inferred avgVWHO, a decline in anoxic-type Chironomus spp, and appearance of oxic-type Heterotrissocladius suggesting that hypolimnetic DO had returned to more oxic conditions. However, it is important to note that the central basin core did not extend to pre-
Better mitigation of anthropogenicstressors on marine ecosystems is urgently needed to address increasing biodiversity losses worldwide. We explore opportunities for stressor mitigation using whole-of-systems modelling of ecological resilience, accounting for complex interactions between stressors, their timing and duration, background environmental condi- tions and biological processes. We then search for ecological windows, times when stressors minimally impact ecological resilience, de ﬁ ned here as risk, recovery and resistance. We show for 28 globally distributed seagrass meadows that stressor scheduling that exploits ecological windows for dredging campaigns can achieve up to a fourfold reduction in recovery time and 35% reduction in extinction risk. Although the timing and length of windows vary among sites to some degree, global trends indicate favourable windows in autumn and winter. Our results demonstrate that resilience is dynamic with respect to space, time and stressors, varying most strongly with: (i) the life history of the seagrass genus and (ii) the duration and timing of the impacting stress.
Alteration to landscapes by humans can seriously impact dynamics of aquatic ecosystems. Examples of such alterations include urbanization and agriculture in which introduced effluent and materials are either directly or indirectly deposited into rivers. In large rivers, reservoirs alter natural flows creating lentic ecosystems susceptible to allochthonous inputs from up-river. In this investigation, phytoplankton community change over a multi-year period in a large shallow reservoir, Lake Seminole, Georgia, links primary producer change to environmental and anthropogenicstressors. Inflows into Lake Seminole differ in that one arm is primarily from urban/industrial areas and the other two are mainly from agricultural regions providing a unique natural experiment regarding land-use effects on phytoplankton dynamics. Phytoplankton community structure was estimated by measuring and analyzing photosynthetic pigments. Stressors to the system included precipitation, temperature, water flow, and the presence of the invasive macrophyte Hydrillci verticillata which is seasonally known to cover up to 50% o f the lake. Results show that average phytoplankton abundance is increased from up- reservoir to down-reservoir and in the presence of Hydrilla verticillata. The
Anthropogenicstressors may have large evolutionary consequences by inducing greater selection pressures than would occur naturally (Reznick and Ghalambor 2001). Thus, exposure to these stressors could potentially result in unprecedented rates of evolution. Traditionally, it was believed that an evolutionary response would take thousands of generations to occur (Darwin 1859). More recently, however, evolutionary biologists have recognized that evolution can also occur over much shorter temporal scales. In general, adaptive evolutionary events occurring over a relatively short time- frame are referred to as ‘contemporary’ or ‘rapid’ evolution (Hendry and Kinnison 1999). Perhaps the most notable example of rapid evolution comes from the medium ground finch (Geospiza fortis) on the Galápagos Island of Daphne Major, where individuals underwent a severe selection event and, consequently, showed signs of adaptive evolution in just one generation (Boag and Grant 1981; 1984; Grant and Grant 1995; 2003). Since this seminal research on G. fortis, interest in rapid evolution has grown considerably, especially over the last decade with the recent realization that most documented examples of rapid evolution are attributed, at least in part, to anthropogenic changes to the
The objective of this study is to evaluate the characteristics of the forest in an urbanised mangrove using vegetation structure and abiotic conditions to distinguish habitat heterogeneity/ quality. A total of 16 points in Vitória Bay were selected in the fringe and basin forests. The variables evaluated were height and diameter of the individual trees, basal area, density, dominance, interstitial water, litter mass, grain size, organic matter and anthropogenic influences. The results indicated that the mangrove area, due to suffering intensely from various anthropogenic effects, forests with varying degrees of maturity. Areas more distant from direct human effects had a higher degree of development and environmental quality relative to points closer to urban pressures. Intermediate development levels were also observed, which indicated pulses of environmental change. Human interventions caused alterations in the development of the forest which increased the mortality rate and reduced the diameter and height of the trees. The environmental variables of salinity, organic matter, litter mass, grain size and anthropogenicstressors contributed to the structural patterns. Our data suggest that an analysis of the vegetation structure and the abiotic factors are useful indicators to evaluate habitat quality, thus providing a basis for future management.
AET states that there is a signi ﬁ cant difference in the intensity of affective experience between individuals activated by affec- tive events. 30,32 As the affective activation embodies a process of cognitive evaluation, the locus of control representing the individual ’ s cognitive attribution tendency will play a moderating role between work stressors and affective experience. 37 Speci ﬁ cally, individuals with a high locus of control tend to attribute the development and results of events to internal factors such as their abilities and behaviors and believe that they can control the events. 37,38 They generally have a higher sense of responsibility and adaptability, 41 and are more willing to invest more effort and attention to get better results. Therefore, in the face of affective events with high work demands such as challenge stressors (dif ﬁ cult work, heavy workload, etc.), individuals with a high locus of control tend to believe that they can control and manipulate challenge stressors, and turn the stressors into factors favourable to self- growth, bringing them more positive affection, such as enthu- siasm, attention and pride. 42 – 44 That is, for supervisors with a high locus of control, challenge stressors have a stronger posi- tive effect on positive affection. Conversely, supervisors with a low locus of control tend to take lower con ﬁ dence in the control and manipulation of challenge stressors, with a much lower possibility of transforming them into self-growth drivers so that they can experience less positive affective experience. In other words, for supervisors with a low locus of control, the positive relationship between challenge stressors and the posi- tive affective experience was weaker. In terms of negative emotional events like hindrance stressors, supervisors with a high locus of control think of hindrance stressors solvable. They can effectively control their detriments despite obstacles
1.5 Expected Findings
The results of this research are expected in helping all the participants especially in construction industry to recognize the stressors and the impact of stressors so that they can consider this issue to improve in the future. On the other hand, this research could encourage in proposing solution to reduce the impact of stressors thus could help in reducing the number of accidents in construction.
Recent research in higher education has provided insights into the environ- mental demands that teachers and lecturers encounter in their workplace (Gillespie, Walsh, Wineield, Dua, & Stough, 2001; Tytherleigh, Webb, Cooper, & Ricketts, 2005; Wineield et al., 2003). For example, longitudinal focus groups conducted at 15 Australian universities revealed that academic staff reported a signiicant increase in occupational stress over a ive year period (Gillespie et al., 2001). The ive main types of organizational stressors they encountered were: insuficient funding and resources, work overload, poor management practice, job insecurity, and insuficient recognition and reward. These indings were supported and extended by Wineield et al. (2003) in their survey of academic staff across 17 Australian universities. The participants identiied a wide variety of stressors pertaining to university manage- ment, hours of work and chances of promotion, industrial relations between man- agement and staff, and rates of pay. Similar indings were reported by Tytherleigh et al. (2005) in their study of academic and nonacademic staff from 14 universities and colleges in the United Kingdom. They highlighted stressors that related to work overload (e.g., insuficient time to complete job), work relationships (e.g., people not fulilling their duties), job insecurity, resources and communication (e.g., not being informed about decisions in the organization), and pay.
country and 69 of these are available through institutions in the province of Sindh and especially Karachi city (Pakistan Nursing Council 2016a). Staying away from family means that these students have to take care of their domestic needs such as cooking, cleaning and clean laundry. Males, in Pakistan culture, are not really expected to have these skills as the female members of the family perform all these tasks. Staying away from family, therefore, can create extra pressures and stressors for the male nursing students in this regard. This m
In the present study, the organizational stressors were examined based on the Occupational Role Stress Scale (ORS) developed by Pareek. The responses against each factor was collected by using five statements on Likert‟s 1 – 5 scale with each response being anchored to numerical value assigned to it from a total of 482IT professionals‟ samples. Thus, calculated mean value of the organizational stressors ranges from a minimum of 1 – Strongly disagree, 2 – Disagree, 3 – Neutral, 4 – Agree and 5 – Strongly agree. Each factor was examined with five statements. The following section deals with the frequency tables of all the ten stressors of occupational stress. All the following tables display the serial number of the statement that was used in the final questionnaire in the first column. The succeeding columns gives the details of the statement, frequencies recorded, calculated mean and standard deviations in sequence.
Invertebrates that transmit far-field sounds in noisy environments have multiple ways of overcoming the challenges associated with anthropogenic noise. First, they can avoid noise spatially by moving away from areas heavily impacted by human activities. Although there is no direct evidence of this in invertebrates, Bunkley et al. (2017) found that grasshoppers and camel crickets were less abundant at gas drilling sites with noise than those without. Second, animals may avoid anthropogenic noise temporally, by calling at times when noise is absent or reduced. However, one source of noise, road traffic, is predictably most intense during dawn and dusk (rush hour), times when many invertebrates concentrate their calling activity (Luther and Gentry, 2013). Researchers have suggested that it is unlikely that invertebrates will be able to temporally shift calling because there are increased costs to calling at other times of day, owing to suboptimal atmospheric conditions, particularly at sunset (Van Staaden and Römer, 1997). In addition, short-term temporal activities for some invertebrates might be constrained by phylogenetic history (Shieh et al., 2015). Third, like some vertebrates, invertebrates could increase the amplitude of their calls (Lombard effect) (Nemeth and Brumm, 2010). However, to
Since the 1950s, small tremors created by human actions have been catalogued and recorded by the USGS. However, there is no academic explanation of the mechanism involved in these quakes. The aim of this work is to show that the propagation of mechanical fractures created in certain areas is one factor re- sponsible for triggering earthquakes. Technically, this fracturing process de- pends on the ratio between pressure and tension, i . e ., Young’s modulus, and locally depends on the specific material under pressure. Examining the entire territory of the U.S., we were able to identify certain states where Griffith’s theory was applied to explain the results found in those states. This study works with public records available from USGS. Therefore, any classified event or information is outside of the scope of this paper. We also investigate mid-continent or intraplate earthquakes during the period 2000-2016 with magnitudes M2 to M3.8 in shallow depths that appear to be amplified in con- sonance with development by companies in fracking, oil-gas assessment, mining, quarry blasting, experimental explosions, and collapses. Of particular interest was the enhancement of earthquakes during 2000-2016 for events M ≥ 4 surrounding the Mississippi Lime near the Oklahoma/Kansas border. Overall, all the anthropogenic events could be elucidated by Griffith theory.
The importance of anthropogenic burning in local and regional environmental histories of has been controversial. The difficulties of identifying anthropogenic influences in empirical fire histories has encouraged a speculative polemic, with some scholars arguing for continental-scale transformation by widespread anthropogenic burning [1,2] and others claiming that human activities were virtually irrelevant prior to the modern era [3–5]. The top-down influences of climate on fuel abundance and flammability coupled with the regularity of natural ignitions in many fire-prone continental environments has led some scholars to conclude that anthropogenic ignitions are of minor consequence historically, particularly when compared to the magnitude of change caused by fuel alterations in recent decades, including the effects of fire suppression [4,6,7]. These debates largely consider human influence with respect to the cumulative area burned per unit of time, in which only area burned and landscape-scale fire frequency matter.
In addition to its significance with regards to anthropogenic climate change, soil carbon influences a whole host of soil biochemical and physical properties. Increased soil carbon is known to improve soil aggregate stability and thus increase water infiltration rate and soil water retention. Soil organic carbon, like soil colloids, has active charge sites where soil cations and anions can be adsorbed. While soil clays tend to have just negatively charged sites, organic carbon also has positively charged sites. Organic carbon also has functional groups that interact with soil minerals and ions in solution. Despite being a small fraction of the soil, organic carbon is significant in soil chemical processes Soil organic carbon, through decomposition, is also a source of nutrients and substrate to plants and soil microorganisms (Brady and Weil, 2010). Since soil organic carbon has a net beneficial impact on soil properties and the capacity of soils to support plant life, practices that increase soil carbon – or at least minimize its loss are
Developing a successful strategy for investigating and remediating sites poten- tially impacted by metals (such as chromium [Cr], copper [Cu], lead [Pb], nickel [Ni], and zinc [Zn]) and metalloids (such as arsenic [As] and antimony [Sb]) can be challenging. These elements occur naturally and geologic mate- rials can be enriched in these elements by natural processes. Conventional en- vironmental investigative methods do not readily support evaluating whether metals and metalloids are geogenic (naturally occurring) or anthropogenic (from human action), or allow differentiating multiple anthropogenic sources. Geochemical methods can potentially determine whether metals and metallo- ids are geogenic or anthropogenic, and differentiate between possible anthro- pogenic sources. Conventional geochemical methods include whole-rock analy- sis using x-ray fluorescence (XRF) to yield elemental concentrations; optical petrography and powder x-ray diffraction (XRD) to determine mineral phases present; and electron microprobe (EMP) to confirm both mineral phases present and the distribution of elements within mineral phases and the rock matrix. These methods, with the exception of the EMP, can be performed in the field using portable equipment, allowing for relatively rapid assessment of sites. A case study is presented in which these techniques were successfully utilized to demonstrate, using multiple lines of evidence, that metals and me- talloids present in subsurface fractured rock were geogenic and unrelated to recent industrial operations.
Traffic noise, together with other types of anthropogenic noise, has become both a biodiversity threat and a potential new selective force affecting the evolutionary processes of some animal species (Forman and Alexander, 1998; Brumm, 2010; Halfwerk et al., 2011b). For animals living in the vicinity of roads, traffic noise may impair their communication (Brumm and Slabbekoorn, 2005), change their vocal signals (Parks et al., 2011), interfere with predator–prey interactions (Siemers and Schaub, 2011) or act as a stressor affecting the neuroendocrine system (Rolland et al., 2012). Consequently, these effects may lead to the reduction of suitable habitats (Bayne et al., 2008), reduced reproductive success (Francis et al., 2011; Halfwerk et al., 2011a; Schroeder et al., 2012), decreased population size (Foote et al., 2004; Reijnen and Foppen, 2006), or altered evolutionary paths (Leonard and Horn, 2005; Luther and Baptista, 2010; Halfwerk et al., 2011b).