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1.
The vermicomposting ability of Lampito mauritii (Kinberg) and Perionyx ceylanensis Michaelsen was evaluated by using three different types of organic substrates such as leaf litter of Polyalthia longifolia, Pennisetum typhoides cobs (pearl millet) and a weed, Rottboellia exaltata (whole plant except the roots) in combination with cowdung (1:1). Vermicomposting studies (120 days) conducted to optimize
the number of worms required for efficient conversion based on the reduction of C/N ratio, percentage decomposition of organic
substrates, total number and biomass of earthworms recovered from the vermibed substrates clearly showed that vermibeds with
4 kg of organic materials can hold about 60–80 L. mauritii and about 90–120 P. ceylanensis for efficient decomposition. The percentage decomposition of each organic substrate treated with different numbers of L. mauritii (20, 40, 60, 80 and 100 earthworms) and P. ceylanensis (30, 60, 90, 120 and 150) showed significant difference (P < 0.001) between numbers of worms introduced per vermibed but the difference between substrates was not significant within the treatments.
Vermicomposting resulted in significant increase in electrical conductivity (28.54–49.82%), total nitrogen (43.96–90.83%),
total phosphorus (27.42–68.10%) and total potassium (27.42–113.18%), whereas decrease in organic carbon (35.05–49.74%), C/N
ratio (55.48–73.18%) and C/P ratio (50.46–66.90%) in different vermibeds introduced with L. mauritii and P. ceylanensis. Both the earthworm species can be used for vermicomposting different organic substrates; however, duration of vermicomposting
with P. ceylanensis is not as much of L. mauritii. The use of L. mauritii for vermicomposting of other substrates has been well established by other workers also but standardization of P. ceylanensis, a locally available species, for vermicomposting of different organic substrates is a new finding and the species could be
useful for vermiconversion of organic substrates under local conditions. 相似文献
2.
Surindra Suthar 《The Environmentalist》2009,29(1):78-84
Epigeic earthworms (Oligochaeta) have been appeared as key organisms to convert organic waste resources into value-added products,
i.e., vermicompost and worm biomass. The assessment of reproduction potential of composting earthworm may be beneficial for
large-scale earthworm production. Although, the waste minimizing potential of Perionyx excavatus and Perionyx sansibaricus is well proved, but little information is available about their fecundity rate. In this study, the efforts have been made
to explore the growth and reproduction biology of P. excavatus and P. sansibaricus, using cattle waste solid as culture substrate, under laboratory conditions. Earthworms were weighed weekly and number of
cocoons produced per week assessed. Biomass productions, fecundity, maturation, natality all were significantly different
between P. excavatus and P. sansibaricus. The highest mean individual biomass was 767.7 ± 18.4 mg and 612.6 ± 20.6 mg, respectively in P. sansibaricus and P. excavatus. However, the highest cocoon numbers occurred in P. excavatus (492.3 ± 13.6), significantly higher than P. sansibaricus (269.6 ± 17.1). Fecundity was slightly different in both species: 1.38 ± 0.77 cocoons adult worm−1 week−1 (P. excavatus) and 1.58 ± 0.74 cocoons adult worm−1 week−1 (P. sansibaricus). The hatchling success rate (%) was highest in P. excavatus. Overall natality (juveniles adult−1 week−1) was highest in P. sansibaricus (1.52) than P. excavatus (1.26), which suggests that P. sansibaricus may be a better candidate for rapid propagation of earthworms in cattle waste solid. 相似文献
3.
R. Naraian R. K. Sahu S. Kumar S. K. Garg C. S. Singh R. S. Kanaujia 《The Environmentalist》2009,29(1):1-7
The cultivation of white rot edible fungus Pleurotus florida was performed in polybags. The corn cob was employed as basal substrate while eight different additives such as urea, ammonium
sulphate, gram flour, soybean meal, ground nut cake and molasses were used with corn cob. Three different levels of variable
combinations with corn cob were evaluated in response to different parameters of mushroom viz., mycelial growth, spawn running,
primordial initiation, fruit body yield and its biological efficiency. Each additive at different combinations showed variable
impact on the different stages of mushroom life cycle. The primordial initiation was observed for the first time during 20.2–35.1 days.
The biological efficiencies in every supplemented set were increased over un-supplemented control set. Increasing the level
of additives, the biological efficiency was negatively affected at higher levels. The cotton seed cake was found the best
supplement producing 93.75% biological efficiency while soybean meal was the second best additive producing 93.00% yield.
The highest growth rate, rapid mycelia run, early primordial initiation, highest yield and biological efficiency were recorded
in the combination of corn cob and cotton seed cake at 2% (98 + 2) level. 相似文献
4.
Madhusudan MD 《Environmental management》2003,32(4):466-475
Dissolved copper was toxic to wild rice (Zizania palustris) seedlings when exposed in water from the seed collection site of Swamp Creek, Crandon, Wisconsin, USA, and in laboratory-prepared artificial or reconstituted water. Seeds for the study were harvested, then held through a portion of dormancy, in Swamp Creek. After 60 days they were shipped to a laboratory, chilled, and tested with copper after germination. The end point of the tests was net gain in wet weight of the seedlings; additionally, a pronounced reduction in root development was observed. Using measured concentrations, the lowest no-observable-effect concentration (NOEC) in our study was 37 g/liter in Swamp Creek water and the lowest-observable-effect concentration (LOEC) was 59 g/liter. However, it appeared that there was a point at which concentrations of copper above 400 g/liter did not result in any measurable effect or exhibit a definitive dose–response. Because the results in Swamp Creek water were more relevant to the possibility of local metals additions and the association of reduced seedling growth by copper was more powerful in this water, we derived an equation to express the relationship between copper concentration and toxicity for Swamp Creek water. As an example, we would expect a 3.0% reduction in seedling growth at 5.0 g/liter copper. Seedling roots were particularly affected and the resultant plants may be less well anchored and more susceptible to dislodging than plants not exposed to copper. Further refinement of the methodology may be used to address effects of other contaminants impacting rice beds in North America.
This study was conducted while the first author was employed by the U.S. Geological Survey, Mid-continent Ecological Science Center, Fort Collins, Colorado 相似文献
5.
Cabruca is an agroforest of cacao trees shaded by native forest trees. It is the predominant vegetation type throughout eastern part
of the range of the golden-headed lion tamarins, Leontopithecus chrysomelas, an endangered primate endemic to Atlantic Forest. Understanding how lion tamarins use this agroforest is a conservation
priority. To address this question, we documented the diet, home range size, group sizes and composition, density, number
of litters and body condition of lion tamarins living in cabruca, and other habitats. Jackfruit, Artocarpus heterophyllus, was the most used species used by lion tamarins in cabruca and was widely available and used throughout the year. In cabruca, home range size was the smallest (22–28 ha) and density of lion tamarins was the highest (1.7 ind/ha) reported for the species.
Group size averaged 7.4 individuals and was not significantly different among the vegetation types. In cabruca, groups produced one or two litters a year, and all litters were twins. Adult males in cabruca were significantly heavier than males in primary forest. Our study is the first to demonstrate that breeding groups of golden-headed
lion tamarins can survive and reproduce entirely within cabruca agroforest. Jackfruit proved to be a keystone resource for lion tamarins in cabruca, and bromeliads were important as an animal prey foraging microhabitat. In cases where cabruca contains concentrated resources, such as jackfruit and bromeliads, lion tamarins may not only survive and reproduce but may
fare better than in other forest types, at least for body condition and reproduction. 相似文献
6.
Salt marshes dominated by Spartina alterniflora and the associated networks of tidal creeks that drain them are characteristic geographical features of southeastern estuaries, important nursery habitat areas, and preferred sites for residential development. As the size of the coastal population increases, so has the number of requests for dock permits. With each new request for a dock permit, public concerns about the cumulative environmental impacts of dock proliferation on the coastal environment have increased. The objective of this particular study was to evaluate the impacts of shading by dock structures on stem densities of S. alterniflora in South Carolina coastal marshes. Shading impacts under individual docks were extrapolated to the tidal creek (local), county, and statewide scales. Dock structures were sampled both under and next to the walkway in the Charleston Harbor area of South Carolina. The density of S. alterniflora under docks was significantly lower than that which occurred next to the docks (i.e., 5 m away) for the short-form, tall-form, and both forms combined. We estimated that shading effects from dock structures in South Carolina decreased the stem density of S. alterniflora by 71%. Dock shading effects were small when evaluated from the perspective of the amount of marsh that occurs within specific tidal creeks (0.03–0.72%), in coastal counties at a maximum dock length (0.01–0.98%), or statewide (0.01–0.13%) at a maximum dock length. However, approximately 7,000 docks have been permitted over the last decade, resulting in a loss of salt marsh equivalent to 60 ha.1Denise M. Sangers present address: Office of Ocean and Coastal Resource Management, South Carolina Department of Health and Environmental Control, 1362 McMillan Avenue, Suite 400 Charleston, South Carolina 29405, USA.
2 A. Frederick Hollands present address: Hollings Marine Laboratory, National Oceanic and Atmospheric Administration, 331 Fort Johnson Road, Charleston, South Carolina 29412, USA. 相似文献
7.
We conducted field surveys and laboratory analyses to test the effects of soil characteristics in habitat mitigation sites and natural sites on the growth and condition of blue elderberry (Sambucus mexicana), which is the sole host plant for the federally threatened Valley elderberry longhorn beetle (Desmocerus californicus dimorphus). Thirty mitigation and 16 natural sites were selected throughout the range of the beetle. We found that although plant relative growth rates were comparable between mitigation sites and a natural site, mitigation sites contained substantially less soil nutrients than mitigation sites. Within mitigation sites, elderberry health and growth were positively correlated with the amount of total nitrogen in soils and less strongly with other soil nutrients and soil moisture. Analyses demonstrated reductions in the relative growth rate of elderberry as mitigation sites aged, and that soil nutrients and soil moisture became depleted over time. For mitigation sites, it took approximately seven years to develop basal stem diameters that have been linked to successful beetle colonization. Mitigation sites have smaller shrubs than natural sites and growth slows as mitigation sites age, thus delaying convergence of conditions between natural and mitigation sites. Analyses of soil particle size and whether sites were within the 100-year floodplain (as an indicator of riparian conditions) were inconclusive. We recommend investigating fertilizing and optimum planting densities for elderberry at restoration and mitigation sites, as well as increasing the duration of irrigation and monitoring. 相似文献
8.
Crab samples, both male and female specie, were purchased from fishermen at the Ojo Rivers, Lagos, Nigeria. The samples separated
into abdomen, muscle tissue, and thorax were oven dried at 80°C for 3 days. The dried samples were then pulverized in a clean
acid-washed mortar and pestle. Approximately 1.00 g each of the pulverized samples was weighed and Zn, Cr, Pb, and Cd were
determined in the solution of the aqua regia digested samples by means of AAS (Buck Scientific 210 GVP model). The results
obtained showed Zn metal to be consistently higher in all the female parts compared to the male with values of 12.92 ± 3.65 μg/g
to 16.03 ± 1.08 μg/g and 9.33 ± 1.77 μg/g to 15.75 ± 1.02 μg/g, respectively. Mean values of 0.39 ± 0.09 μg/g and 0.22 ± 0.02 μg/g
cadmium were found in the abdomen and tissue of the male crab as against 0.35 ± 0.07 μg/g and 0.17 ± 0.07 μg/g in the female
crab. The tissues of both species have comparable value of chromium. Lead was below the detection limit of 0.05 μg/g in the
tissues of male crab but the female tissue contained 0.83 ± 0.13 μg/g and in other parts identified, lead was consistently
higher than the 2.00 μg/g permissible level of WHO in foods. A simple pair t-test did not demonstrate any significant difference in the distribution of metals between the male and female crabs. The
coefficient of variation (CV) calculated for each metal with respect to the studied parts showed Pb to be widely distributed
(56.23–89.54%) while Cr did not vary widely (4.17–8.20%). 相似文献
9.
At the Sulm River, an Austrian lowland river, an ecologically orientated flood protection project was carried out from 1998-2000. Habitat modeling over a subsequent 3-year monitoring program (2001-2003) helped assess the effects of river bed embankment and of initiating a new meander by constructing a side channel and allowing self-developing side erosion. Hydrodynamic and physical habitat models were combined with fish-ecological methods. The results show a strong influence of riverbed dynamics on the habitat quality and quantity for the juvenile age classes (0+, 1+, 2+) of nase (Chondrostoma nasus), a key fish species of the Sulm River. The morphological conditions modified by floods changed significantly and decreased the amount of weighted usable areas. The primary factor was river bed aggradation, especially along the inner bend of the meander. This was a consequence of the reduced sediment transport capacity due to channel widening in the modeling area. The higher flow velocities and shallower depths, combined with the steeper bank angle, reduced the Weighted Useable Areas (WUAs) of habitats for juvenile nase. The modeling results were evaluated by combining results of mesohabitat-fishing surveys and habitat quality assessments. Both, the modeling and the fishing results demonstrated a reduced suitability of the habitats after the morphological modifications, but the situation was still improved compared to the pre-restoration conditions at the Sulm River. 相似文献
10.
Kirk W. Davies Jonathan D. Bates Dustin D. Johnson Aleta M. Nafus 《Environmental management》2009,44(1):84-92
Mowing is commonly implemented to Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh (Wyoming big sagebrush) plant communities to improve wildlife habitat, increase forage production
for livestock, and create fuel breaks for fire suppression. However, information detailing the influence of mowing on winter
habitat for wildlife is lacking. This information is crucial because many wildlife species depended on A. tridentata spp. wyomingensis plant communities for winter habitat and consume significant quantities of Artemisia during this time. Furthermore, information is generally limited describing the recovery of A. tridentata spp. wyomingensis to mowing and the impacts of mowing on stand structure. Stand characteristics and Artemisia leaf tissue crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) concentrations were measured
in midwinter on 0-, 2-, 4-, and 6-year-old fall-applied mechanical (mowed at 20 cm height) treatments and compared to adjacent
untreated (control) areas. Mowing compared to the control decreased Artemisia cover, density, canopy volume, canopy elliptical area, and height (P < 0.05), but all characteristics were recovering (P < 0.05). Mowing A. tridentata spp. wyomingensis plant communities slightly increases the nutritional quality of Artemisia leaves (P < 0.05), but it simultaneously results in up to 20 years of decrease in Artemisia structural characteristics. Because of the large reduction in A. tridentata spp. wyomingensis for potentially 20 years following mowing, mowing should not be applied in Artemisia facultative and obligate wildlife winter habitat. Considering the decline in A. tridentata spp. wyomingensis-dominated landscapes, we caution against mowing these communities. 相似文献
11.
12.
Clementina O. Adenipekun Olusola J. Oyetunji Luqman S. Kassim 《The Environmentalist》2008,28(4):446-450
The effect of spent engine oil on the height, leaf number, leaf area, stem girth, chlorophyll, and moisture contents of Corchorus olitorius grown on 0, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, and 3.0% (v/w oil/soil) oil-contaminated soil was investigated. The engine
oil at all concentrations delayed the germination of C. olitorius by 2 days (compared to control) and there was a general significant reduction in all the growth parameters in plants grown
on contaminated soil compared to control plants. The highest leaf area of 26.8 cm2 was found in the control plant and least was found in the 0.6% soil (0.11 cm2) after 3 weeks while no values were recorded on the 0.8–3.0% engine-oil-contaminated soil after 5 weeks of experiment. The
highest chlorophyll content was also found in the control plant (11.5 mg/l). This showed that spent engine oil has an adverse
effect on the growth of C. olitorius plant. 相似文献
13.
Here we report N2O emission results for freshwater marshes isolated from human activities at the Sanjiang Experimental Station of Marsh Wetland
Ecology in northeastern China. These results are important for us to understand N2O emission in natural processes in undisturbed freshwater marsh. Two adjacent plots of Deyeuxia angustifolia freshwater marsh with different water regimes, i.e., seasonally waterlogged (SW) and not- waterlogged (NW), were chosen for
gas sampling, and soil and biomass studies. Emissions of N2O from NW plots were obviously higher than from the SW plots. Daily maximum N2O flux was observed at 13 o′clock and the seasonal maximum occurred in end July to early August. The annual average N2O emissions from the NW marsh were 4.45 μg m−2 h−1 in 2002 and 6.85 μg m−2 h−1 in 2003 during growing season. The SW marsh was overall a sink for N2O with corresponding annual emissions of −1.00 μg m−2 h−1 for 2002 and −0.76 μg m−2 h−1 for 2003. There were significant correlations between N2O fluxes and temperatures of both air and 5-cm-depth soil. The range of soil redox potential 200–400 mV appeared to be optimum
for N2O flux. Besides temperature and plant biomass, the freeze–thaw process is also an important factor for N2O emission burst. Our results show that the freshwater marsh isolated from human activity in northeastern China is not a major
source of N2O. 相似文献
14.
Southern California desert public lands receive especially high levels of off-highway recreation due to large population centers
nearby and popular riding environments such as sand dunes. Controversy has developed over the flat-tailed horned lizard (Phrynosoma mcallii), previously a candidate for listing under the Endangered Species Act. Some evidence suggests lower lizard abundance in areas
of higher recreational use than in areas with low or no use. We designed a manipulative experiment to ensure maximum inference
in evaluating the direct impact of recreational riding of off-highway vehicles on lizards. Thirty-six lizards, in situ, were
treated with an off-highway vehicle treatment during hibernation season in three treatment groups: high impact, low impact,
and control. Treatments consisted of timed riding by off-highway vehicles. In all treatment groups survival was 100%, despite
hibernation of lizards at very shallow depths. Consequently, indirect effects of off-highway vehicles deserve increased attention.
The relative importance of direct versus indirect (i.e., degradation of lizard habitat) impacts caused by off-highway vehicles
remains unknown. These indirect effects may include the altering of vegetation, substrate, and prey. We recommend that a manipulative
approach be adopted to investigate these possibilities. 相似文献
15.
In many semi-arid environments of Mediterranean ecosystems, white poplar (Populus alba L.) is the dominant riparian tree and has been used to recover degraded areas, together with other native species, such as
ash (Fraxinus angustifolia Vahl.) and hawthorn (Crataegus monogyna Jacq.). We addressed three main objectives: (1) to gain an improved understanding of some specific relationships between
environmental parameters and leaf-level physiological factors in these riparian forest species, (2) to compare the leaf-level
physiology of these riparian species to each other, and (3) to compare leaf-level responses within native riparian plots to
adjacent restoration plots, in order to evaluate the competence of the plants used for the recovery of those degraded areas.
We found significant differences in physiological performance between mature and young white poplars in the natural stand
and among planted species. The net assimilation and transpiration rates, diameter, and height of white poplar plants were
superior to those of ash and hawthorn. Ash and hawthorn showed higher water use efficiency than white poplar. White poplar
also showed higher levels of stomatal conductance, behaving as a fast-growing, water-consuming species with a more active
gas exchange and ecophysiological competence than the other species used for restoration purposes. In the restoration zones,
the planted white poplars had higher rates of net assimilation and water use efficiency than the mature trees in the natural
stand. We propose the use of white poplar for the rapid restoration of riparian vegetation in semi-arid Mediterranean environments.
Ash and hawthorn can also play a role as accompanying species for the purpose of biodiversity. 相似文献
16.
17.
We have made an attempt to understand the significance of physiographic factors viz., altitude, aspect, slope and soil characteristics
in determining the structure, composition, growth behavior and distribution of Himalayan Silver Fir (Abies pindrow Spach.) through a comparative analysis of two temperate forests. The occurrence of highest density (370 and 225 ind/ha),
importance value index (213.10 and 190.60) and total basal cover (TBC; 95.72 and 51.15 m2/ha) values along with the availability of higher organic carbon (6.53 and 4.47%), nitrogen (N; 0.73 and 0.44%) and potassium
(K; 621 and 319 ppm) contents in the soils just beneath the hilltops (2,650–2,800 and 2,550–2,650 m asl), on steeper slopes
(45°–50° and 42°–45°) and North-East aspects have revealed better growth of A. pindrow on both the sites. Stem density positively correlated with TBC (0.771), Shannon–Wiener diversity index (H′; 0.879), OC (0.601),
N (0.758) and K (0.752), whereas TBC has shown significant positive relationship with H′ (0.894), K (0.793) and N (0.716).
Similarly, H′ has also shown significant positive correlation with slope (0.721), K (0.855) and N (0.791). Interestingly,
positive correlation of altitude with stem density (0.557) and of slope with TBC (0.608) was noticed in the distribution of
A. pindrow individuals. 相似文献
18.
Summary The biomass and productivity of a montane grassland of Garhwal Himalaya were estimated with the objectives to compare these
values of the dominant exotic species, Eupatorium glandulosum HBK. (Asteraceae) with other species, and to compare the sites more dominated by this species with other study sites. The
effect of dominance of this species on other species was undertaken because of its continuous spread in the grasslands of
the Garhwal Himalaya causing replacement of some native grasses and economically important herbaceous plants. Out of six study
sites, SW1, SW2, and NE1 were more dominated by Eupatorium glandulosum. Total net primary productivity (TNP) ranged from 1528.5 to 2163.4 g m−2 yr−1. Eupatorium glandulosum showed individual highest biomass on all the study sites, and the sites more dominated by this species showed higher values
of primary productivity, thereby reducing the biomass and production of other species on these sites. 相似文献
19.
Physico-chemical characteristics of the feed and optimum worm density are important parameters for the efficient working of
a vermicomposting system. Overcrowding of worms can affect the efficiency of a vermicomposting system even if all other parameters
have been optimized. This article reports the effect of stocking density and feed quality on the growth and fecundity of Eisenia fetida under laboratory conditions. The feed mixtures contained cow dung and textile mill wastewater sludge in different ratios.
Three feed mixtures and five stocking rates (1, 2, 4, 8, and 12) were tested for 12 weeks. The results showed that E. fetida growth rate was faster at higher stocking densities; however, biomass gain per worm was faster at lower stocking densities.
Sexual maturity was attained earlier at higher stocking densities. Growth rate was highest in 100% cow dung at all the stocking
densities when compared to textile mill wastewater sludge containing feed mixtures. A worm population of 27–53 worms per kg
of feed was found to be the most favorable stocking density. 相似文献
20.
Nsikak U. Benson Joseph P. Essien Godwin A. Ebong Akan B. Williams 《The Environmentalist》2008,28(3):275-282
The levels of total petroleum hydrocarbons in two commonly consumed benthopelagic shellfishes, Macura reptantia and Procambarus clarkii, harvested from benthic sediment of Qua Iboe Estuary were determined using a gas chromatography with flame-ionization detector.
Seventy-two (72) samples each of benthic sediment and the shellfishes were collected monthly between June 2003 and February
2004 covering the peak periods of the wet and dry seasons. Concentrations of hydrocarbons were highly variable and ranged
between 5.00 and 232.00 μg/g dry weight of benthic sediment, 3.05 and 11.30 μg/g dry weight of M. reptantia, 1.62 and 9.00 μg/g dry weight of P. clarkii. Pearson’s correlation analysis of total hydrocarbon concentrations in subtidal sediments with levels in the fauna species
yielded positive significant (P < 0.05) correlations in M. reptantia (r = 0.737) and P. clarkii (r = 0.924). This is indicative of a long term and chronic accumulation of hydrocarbons in the estuarine ecosystem, reflecting
the potential for exposure of the resident biota and the risk to human health. 相似文献