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Panicum maximum (guinea grass), a native grass of Africa, has invaded and displaced the native Miscanthus sinensis grassland at Dadu terrace in central Taiwan. The Dadu terrace has distinct wet and dry seasons and is prone to fire...
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Panicum maximum (guinea grass), a native grass of Africa, has invaded and displaced the native Miscanthus sinensis grassland at Dadu terrace in central Taiwan. The Dadu terrace has distinct wet and dry seasons and is prone to fire during the dry seasons. We compared photosynthesis and growth, as well as the growth response to two water treatments, between P.maximum and M.sinensis plants to understand ecophysiological factors contributing to the successful invasion of the grass. In comparison with M.sinensis, P.maximum had a significantly higher photosynthetic rate, larger specific leaf area and a higher leaf area/total biomass ratio, and thus grew faster and higher, and accumulated more biomass under well-watered conditions. The growth of P.maximum was more susceptible than M.sinensis to drought stress. Faster growth of seedlings and more biomass accumulation of mature plants would give P.maximum a highly competitive advantage over M.sinensis for resource acquisition in the Dadu terrace during the wet season, which might contribute to the successful invasion of P.maximum into the grassland of M.sinensis.
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Aim : Sewan grass (Lasiurus sindicus Henr.), considered as the "King of Desert Grasses", is a dominant grass species of hot arid ecosystem of Great Indian Desert, covering Western Rajasthan and parts of Pakistan. This grass is ext...
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Aim : Sewan grass (Lasiurus sindicus Henr.), considered as the "King of Desert Grasses", is a dominant grass species of hot arid ecosystem of Great Indian Desert, covering Western Rajasthan and parts of Pakistan. This grass is extremely drought resistant and thrives even in areas receiving very low rainfall (100 to 150 mm) annually under extreme temperatures ranging from -3 to 50 degrees C. The present study was undertaken to analyze the extent of genetic variability existing among the L. sindicus germplasm collected from Bikaner, Barmer and Jaisalmer, the diversity rich districts of hyper-arid Rajasthan, using ISSR and RAPD markers.
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Questions: What is the impact on non-target species of restoration methods to establish Calluna vulgaris on grass-dominated moorlands?Location: A Nardus stricta-dominated moorland in Wales and a Molinia caerulea-dominated moorland...
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Questions: What is the impact on non-target species of restoration methods to establish Calluna vulgaris on grass-dominated moorlands?Location: A Nardus stricta-dominated moorland in Wales and a Molinia caerulea-dominated moorland in Northern England, UK.Methods: Two replicated experiments were established on grass-dominated moorlands. The treatments comprised disturbance (rotavation and trampling by animals), addition of Calluna seed, and three different grazing regimes, together with a no grazing control.Results: The creation of bare ground and addition of seed increased the establishment of the desired dominant shrub, Calluna vulgaris. In the Nardus sward, rotavation and trampling were equally Successful in establishing Calluna, but rotavation was more successful in the Molinia sward. Rotavation inhibited the growth of competitive grass species better than trampling. However, the disturbance techniques were detrimental to other components of the plant community, causing a decline in the cover of desirable species Such as Vaccinium myrtillus and other dwarf shrub species and a small increase in the Occurrence of undesirable species such as Juncus effusus. Grazing also controlled competitive grass species: Festuca ovina decreased in cover at a grazing intensity of 1.5 ewes/ha; Molinia caerulea and Agrostis spp. declined when cattle were included in the grazing regime, but increased in cover when ungrazed or when grazed at 1.5 ewes/ha.Conclusions: When restoration concentrates on the establishment of one or a few species, it is important to monitor how the techniques used affect the rest of the plant community - particularly with regard to losses of desirable species or increases in undesirable species.
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Questions: What is the impact on non-target species of restoration methods to establish Calluna vulgaris on grass-dominated moorlands?Location: A Nardus stricta-dominated moorland in Wales and a Molinia caerulea-dominated moorland...
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Questions: What is the impact on non-target species of restoration methods to establish Calluna vulgaris on grass-dominated moorlands?Location: A Nardus stricta-dominated moorland in Wales and a Molinia caerulea-dominated moorland in Northern England, UK.Methods: Two replicated experiments were established on grass-dominated moorlands. The treatments comprised disturbance (rotavation and trampling by animals), addition of Calluna seed, and three different grazing regimes, together with a no grazing control.Results: The creation of bare ground and addition of seed increased the establishment of the desired dominant shrub, Calluna vulgaris. In the Nardus sward, rotavation and trampling were equally Successful in establishing Calluna, but rotavation was more successful in the Molinia sward. Rotavation inhibited the growth of competitive grass species better than trampling. However, the disturbance techniques were detrimental to other components of the plant community, causing a decline in the cover of desirable species Such as Vaccinium myrtillus and other dwarf shrub species and a small increase in the Occurrence of undesirable species such as Juncus effusus. Grazing also controlled competitive grass species: Festuca ovina decreased in cover at a grazing intensity of 1.5 ewes/ha; Molinia caerulea and Agrostis spp. declined when cattle were included in the grazing regime, but increased in cover when ungrazed or when grazed at 1.5 ewes/ha.Conclusions: When restoration concentrates on the establishment of one or a few species, it is important to monitor how the techniques used affect the rest of the plant community - particularly with regard to losses of desirable species or increases in undesirable species.
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In semi-arid areas, multiple equilibrium states of an ecosystem ( e. g., grassland and desert) are found to coexist, and the transition from grassland to desert is often abrupt at the boundary. A simple ecosystem model is develope...
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In semi-arid areas, multiple equilibrium states of an ecosystem ( e. g., grassland and desert) are found to coexist, and the transition from grassland to desert is often abrupt at the boundary. A simple ecosystem model is developed to provide the biophysical explanation of this phenomenon. The model has three variables: living biomass, wilted biomass, and soil wetness. The moisture index, which is the ratio of the annual precipitation to potential evaporation, is the only external climate driving force, and the key mechanism is the vegetation-soil interaction. It is found that the maintenance of a grassland requires a minimum moisture index, and the abrupt transition occurs when the moisture index is around this critical value. These results are robust within a wide range for most model parameters, suggesting that the model may be applicable to other temperate grasslands. The characteristics of the wilted biomass also strongly influence the ecosystem's dynamics. [References: 11]
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Rewetting of drained peatlands has been recommended to reduce CO<sub>2</sub> emissions and to restore the carbon sink function of peatlands. Recently, the combination of rewetting and biomass production (paludiculture) has gained ...
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Rewetting of drained peatlands has been recommended to reduce CO<sub>2</sub> emissions and to restore the carbon sink function of peatlands. Recently, the combination of rewetting and biomass production (paludiculture) has gained interest as a possible land use option in peatlands for obtaining such benefits of lower CO<sub>2</sub> emissions without losing agricultural land. This study quantified the carbon balance (CO<sub>2</sub>, CH<sub>4</sub> and harvested biomass C) of rewetted and drained peat soils under intensively managed reed canary grass (RCG) cultivation. Mesocosms were maintained at five different groundwater levels (GWLs), that is 0, 10, 20?cm below the soil surface, representing rewetted peat soils, and 30 and 40?cm below the soil surface, representing drained peat soils. Net ecosystem exchange (NEE) of CO<sub>2</sub> and CH<sub>4</sub> emissions was measured during the growing period of RCG (May to September) using transparent and opaque closed chamber methods. The average dry biomass yield was significantly lower from rewetted peat soils (12?Mg?ha<sup>?1</sup>) than drained peat soils (15?Mg?ha<sup>?1</sup>). Also, CO<sub>2</sub> fluxes of gross primary production (GPP) and ecosystem respiration (ER) from rewetted peat soils were significantly lower than from drained peat soils, but net uptake of CO<sub>2</sub> was higher from rewetted peat soils. Cumulative CH<sub>4</sub> emissions were negligible (0.01?g CH<sub>4</sub>?m<sup>?2</sup>) from drained peat soils but were significantly higher (4.9?g CH<sub>4</sub>?m<sup>?2</sup>) from rewetted peat soils during measurement period (01 May–15 September 2013). The extrapolated annual C balance was 0.03 and 0.68?kg C m<sup>?2</sup> from rewetted and drained peat soils, respectively, indicating that rewetting and paludiculture can reduce the loss of carbon from peatlands.
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Rewetting combined with biomass crop cultivation (paludiculture) has been proposed as a method for reducing carbon dioxide (CO<sub>2</sub>) emissions from drained peatlands. This field experiment compared CO<sub>2</sub> fluxes fro...
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Rewetting combined with biomass crop cultivation (paludiculture) has been proposed as a method for reducing carbon dioxide (CO<sub>2</sub>) emissions from drained peatlands. This field experiment compared CO<sub>2</sub> fluxes from drained (control) and rewetted experimental plots in a temperate fen under reed canary grass cultivation over two successive years. The annual weighted mean water table depth from soil surface (WTD) during the study period was 9, 3 and 1 cm in control, semi-flooded and flooded plots, respectively. There were no significant effects of WTD treatment on biomass yields. The choice of response model for CO<sub>2</sub> fluxes influenced annual estimates of ecosystem respiration (ER) and gross primary production (GPP), but all models showed that ER and GPP decreased in response to rewetting. The resulting net ecosystem exchange (NEE) of CO<sub>2</sub>, derived by combining eight ER and eight GPP models, varied widely. For example, NEE (expressed as CO<sub>2</sub>-C) ranged from 935 to -208 g m<sup>-2</sup> yr<sup>-1</sup> for the flooded plots. One set of ER and GPP models was selected on the basis of statistical criteria and showed insignificant differences in NEE between the three water table treatments ( 537 to -341 g CO<sub>2</sub>-C m<sup>-2</sup> yr<sup>-1</sup>). Treatment effects on CO<sub>2</sub> emission factors, calculated as the sum of NEE and C export in harvested biomass (58–242 g CO<sub>2</sub>-C m<sup>-2</sup> yr<sup>-1</sup>), were similarly insignificant. Thus, the results indicated that varying WTD within this narrow range could influence both ER and GPP without altering the net emissions of CO<sub><sup>2</sup></sub>.
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A workshop focusing on invasive annual grass management in sagebrush steppe was held on December 14 and 15，2020 The workshop was attended by 250 participants with over 30 presenters.This special issue of Rangelands includes paper...
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A workshop focusing on invasive annual grass management in sagebrush steppe was held on December 14 and 15，2020 The workshop was attended by 250 participants with over 30 presenters.This special issue of Rangelands includes papers authored by the presenters on the topics covered in the workshop.Under skies choked with wildfire smoke from millions of acres of incinerated sagebrush, charred bunchgrasses, and scorched earth, a force has been gathering. Dedicated land managers, researchers, landowners, social scientists, nonprofits, and wildlife champions have begun to emerge from their silos to share knowledge, resources, and responsibility for addressing an endless onslaught of invading annual grasses and catastrophic wildfire threatening our communities, ecosystems, and livelihoods.
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Energy insecurity and degradation of life supporting ecosystems are the major causes of perpetuating poverty in rural India. Here, we propose the concept of establishing diverse perennial cropping systems (DPCS) for bioenergy feed...
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Energy insecurity and degradation of life supporting ecosystems are the major causes of perpetuating poverty in rural India. Here, we propose the concept of establishing diverse perennial cropping systems (DPCS) for bioenergy feedstock production and ecological rehabilitation of marginal lands. DPCS are the high-diversity communities of tall-perennial native grasses which can produce abundant biomass on low productive lands without or with minimal external inputs and sustain numerous ecosystem services for local people. These have the potential of supporting a broad range of ecosystem services such as biodiversity conservation, ecological restoration of degraded ecosystems, relaxation in human-animal conflict, and promoting industrialization and new local jobs. Basic research underpinning the proposed concept of DPCS, its relevance and policy framework in India, research gaps and limitations are also discussed. (C) 2017 Elsevier B.V. All rights reserved.
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Energy insecurity and degradation of life supporting ecosystems are the major causes of perpetuating poverty in rural India. Here, we propose the concept of establishing diverse perennial cropping systems (DPCS) for bioenergy feed...
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Energy insecurity and degradation of life supporting ecosystems are the major causes of perpetuating poverty in rural India. Here, we propose the concept of establishing diverse perennial cropping systems (DPCS) for bioenergy feedstock production and ecological rehabilitation of marginal lands. DPCS are the high-diversity communities of tall-perennial native grasses which can produce abundant biomass on low productive lands without or with minimal external inputs and sustain numerous ecosystem services for local people. These have the potential of supporting a broad range of ecosystem services such as biodiversity conservation, ecological restoration of degraded ecosystems, relaxation in human-animal conflict, and promoting industrialization and new local jobs. Basic research underpinning the proposed concept of DPCS, its relevance and policy framework in India, research gaps and limitations are also discussed. (C) 2017 Elsevier B.V. All rights reserved.
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