Politics of the natural vegetation to balance the hazardous level of elements in marble polluted ecosystem through phytoremediation and physiological responses

The current paper evaluates the phytoremediation ability and physiological responses of selected resistant plant species to the hazardous levels of elements in the marble waste polluted ecosystem. Preliminary results demonstrate that all the indicator/resistant plant species i.e., Ailanthus altissima, Arundo donax, Cynodon dactylon, Erigeron canadensis, Cannabis sativa, Ficus carica, Lathyrus aphaca, Morus alba, Populus alba, Robinia pseudoacacia and Vitex negundo were the best Phyto-extractors and Phyto-stabilizers for most of the heavy metals in general and Mg, Ca, Fe, Cu and Na in particular (at p < 0.05). Structural Equation Modeling confirmed that marble waste pollution has a direct and significant (R2 =0.80) impact on proline synthesis and hence a role in combating the pollution. Chlorophyll content decreased by 4% in studied plant species when the concentration of pollutants increased. It is concluded that the studied bio-indicators - the abundant plant species of the Marble Waste Polluted Systems (MWPS) have a significant role in its remediation. Increasing proline accumulation and decreasing chlorophyll contents with an increase in pollution in the studied plants show resilience of the ecosystem in response to the external lithospheric toxicities. It is recommended that the recognized plant species could be planted abundantly to remediate the MWPS around the marble processing and other such industries and their catchments

Ecological gradient analyses of plant associations in the Thandiani forests of the Western Himalayas, Pakistan

In the summers of 2012 and 2013, vegetation of Thandiani in the Western Himalayas of Pakistan was surveyed and quantified. We took evidence from relationships between 252 species and 11 measured environmental factors as well as changes in the associations’ structure among 50 analysed stations with 1500 m2 plots. We analysed how the plant associations differ and develop under the influence of their respective ecological gradients. Preliminary results showed that the family Pinaceae was the most abundant family with a family importance value (FIV) of 1892.4, followed by Rosaceae with FIV = 1478.2. Rosaceae, represented by 20 species, was the most dominant family, followed by Asteraceae and Ranunculaceae with 14 and 12 species each, respectively. Analyses via CANOCO software version 4.5 and GEO database demonstrated strong correlations among species distributions and environmental variables, i.e. elevation, topography, and edaphic factors. Our findings show an increase in species diversity and richness from lower elevation (1290 m at sea level (m asl) to higher elevation (2626 m asl). It is evident that aspect, elevation, and soil factors were the decisive variables affecting qualitative and quantitative attributes of vegetation in the study area. The P value ≤ 0.002 confirms a significant impact of abiotic factors that bring variation in vegetation. A 3D view of the study area was generated in ArcScene showing all the five plant associations. Graphs of scatter plot, point profile, and 3D line profile were added to the layout of plant association maps. The habitats of the five association types overlapped broadly but still retained their specific individuality. The execution of GIS framework gave spatial modelling, which ultimately helped in the recognition of indicator species of specific habitat or association type. These findings could further be utilised in devising the forest policy and conservation management. This study also opens new doors of research in the field of biogeography, systematics, and wildlife

Are peatlands in different states with respect to their thermodynamic behaviour? A simple test of peatland energy and entropy budgets

Whilst all ecosystems must obey the second law of thermodynamics, these physical bounds and controls on ecosystem evolution and development are largely ignored across the ecohydrological literature. To unravel the importance of these underlying restraints on ecosystem form and function, and their power to inform our scientific understanding, we have calculated the entropy budget of a range of peat ecosystems. We hypothesize that less disturbed peatlands are ‘near equilibrium’ with respect to the second law of thermodynamics and thus respond to change by minimizing entropy production. This ‘near equilibrium’ state is best achieved by limiting evaporative losses. Alternatively, peatlands ‘far-from-equilibrium’ respond to a change in energy inputs by maximizing entropy production which is best achieved by increasing evapotranspiration. To test these alternatives this study examined the energy balance time series from seven peatlands across a disturbance gradient. We estimate the entropy budgets for each and determine how a change in net radiation (ΔRn) was transferred to a change in latent heat flux (ΔλE). The study showed that: (i) The transfer of net radiation to latent heat differed significantly between peatlands. One group transferred up to 64% of the change in net radiation to a change in latent heat flux, while the second transferred as little as 27%. (ii) Sites that transferred the most energy to latent heat flux were those that produced the greatest entropy. The study shows that an ecosystem could be ‘near equilibrium’ rather than ‘far from equilibrium’

Impact of forest plantation on methane emissions from tropical peatland

Tropical peatlands are a known source of methane (CH4) to the atmosphere, but their contribution to atmospheric CH4 is poorly constrained. Since the 1980s, extensive areas of the peatlands in Southeast Asia have experienced land‐cover change to smallholder agriculture and forest plantations. This land‐cover change generally involves lowering of groundwater level (GWL), as well as modification of vegetation type, both of which potentially influence CH4 emissions. We measured CH4 exchanges at the landscape scale using eddy covariance towers over two land‐cover types in tropical peatland in Sumatra, Indonesia: (a) a natural forest and (b) an Acacia crassicarpa plantation. Annual CH4 exchanges over the natural forest (9.1 ± 0.9 g CH4 m−2 year−1) were around twice as high as those of the Acacia plantation (4.7 ± 1.5 g CH4 m−2 year−1). Results highlight that tropical peatlands are significant CH4 sources, and probably have a greater impact on global atmospheric CH4 concentrations than previously thought. Observations showed a clear diurnal variation in CH4 exchange over the natural forest where the GWL was higher than 40 cm below the ground surface. The diurnal variation in CH4 exchanges was strongly correlated with associated changes in the canopy conductance to water vapor, photosynthetic photon flux density, vapor pressure deficit, and air temperature. The absence of a comparable diurnal pattern in CH4 exchange over the Acacia plantation may be the result of the GWL being consistently below the root zone. Our results, which are among the first eddy covariance CH4 exchange data reported for any tropical peatland, should help to reduce the uncertainty in the estimation of CH4 emissions from a globally important ecosystem, provide a more complete estimate of the impact of land‐cover change on tropical peat, and develop science‐based peatland management practices that help to minimize greenhouse gas emissions.</p

The three-peat challenge: business as usual, responsible agriculture, and conservation and restoration as management trajectories in global peatlands

Peatlands are a globally important carbon store, but peatland ecosystems from high latitudes to the tropics are highly degraded due to increasingly intensive anthropogenic activity, making them significant greenhouse gas (GHG) sources. Peatland restoration and conservation have been proposed as a nature-based solution to climate change, by restoring the function of peatlands as a net carbon sink, but this may have implications for many local communities who rely on income from activities associated with transformed peatlands, particularly those drained for agriculture. However, without changing the way that humans interact with and exploit peatlands in most regions, peatlands will continue to degrade and be lost. We propose that there are ultimately three potential trajectories for peatland management: business as usual, whereby peatland carbon sink capacity continues to be eroded, responsible agricultural management (with the potential to mitigate emissions, but unlikely to restore peatlands as a net carbon sink), and restoration and conservation. We term this the three-peat challenge, and propose it as a means to view the benefits of restoring peatlands for the environment, as well as the implications of such transitions for communities who rely on ecosystem services (particularly provisioning) from degraded peatlands, and the consequences arising from a lack of action. Ultimately, decisions regarding which trajectories peatlands in given localities will follow torequire principles of equitable decision-making, and support to ensure just transitions, particularly for communities who rely on peatland ecosystems to support their livelihoods