scholarly journals Earthworm population ecology; Guyana, S A

2019 ◽  
Author(s):  
Reshma Persaud
Keyword(s):  
Global Climate ◽  
Organic Matter Content ◽  
Terrestrial Ecosystem ◽  
Distinct Species ◽  
Matter Content ◽  
Steady Increase ◽  
Statistical Significant Difference ◽  
Soil Ecosystems ◽  
Significant Difference ◽  
Earthworm Population

Earthworms are regarded as the bio-indicators of soil quality and are perhaps the most significant regulators of soil structure and organic matter content in a variety of terrestrial soil ecosystems, paving the way for sustainable green agriculture and land rehabilitation. Due to the steady increase in industrialization and shifts in global climate, their population is now more susceptible to change/decline as a result of the strains placed on soil ecosystems by agriculture, mining and deforestation. This research aimed to and successfully established the composition of earthworm populations present in Guyana while exploring their relationship with the biogeographical regions and pedobiological components of their respective ecosystem. Earthworms and soil samples were collected from 15 sites per natural region after which they were taxonomically identified following methodological dissections which yielded 68 distinct species. Of the four natural regions, the earthworm population of Highland Region was found to be the most diverse, rich, even and dense. Earthworm abundance, epigeic abundance, endogeic abundance, anecic abundance and species richness among the four natural regions of Guyana, were all of statistical significant difference, likewise, earthworm abundance in the various climate and soil types along with disturbance were of statistical significant difference. It was found that epigeic earthworms were significantly affected by phosphorus (0.01), moisture (0.01) and calcium (0.02) while anecic earthworms were significantly affected by magnesium (0.04), and the degree at which these affect the various ecotype is different among natural regions. This study has proven with conviction that earthworm population structure varies depending on the biogeographical and pedobiological factors present within any respective terrestrial ecosystem.

scholarly journals Earthworm population ecology; Guyana, S A

2019 ◽  
Author(s):  
Reshma Persaud
Keyword(s):  
Global Climate ◽  
Organic Matter Content ◽  
Terrestrial Ecosystem ◽  
Distinct Species ◽  
Matter Content ◽  
Steady Increase ◽  
Statistical Significant Difference ◽  
Soil Ecosystems ◽  
Significant Difference ◽  
Earthworm Population

Earthworms are regarded as the bio-indicators of soil quality and are perhaps the most significant regulators of soil structure and organic matter content in a variety of terrestrial soil ecosystems, paving the way for sustainable green agriculture and land rehabilitation. Due to the steady increase in industrialization and shifts in global climate, their population is now more susceptible to change/decline as a result of the strains placed on soil ecosystems by agriculture, mining and deforestation. This research aimed to and successfully established the composition of earthworm populations present in Guyana while exploring their relationship with the biogeographical regions and pedobiological components of their respective ecosystem. Earthworms and soil samples were collected from 15 sites per natural region after which they were taxonomically identified following methodological dissections which yielded 68 distinct species. Of the four natural regions, the earthworm population of Highland Region was found to be the most diverse, rich, even and dense. Earthworm abundance, epigeic abundance, endogeic abundance, anecic abundance and species richness among the four natural regions of Guyana, were all of statistical significant difference, likewise, earthworm abundance in the various climate and soil types along with disturbance were of statistical significant difference. It was found that epigeic earthworms were significantly affected by phosphorus (0.01), moisture (0.01) and calcium (0.02) while anecic earthworms were significantly affected by magnesium (0.04), and the degree at which these affect the various ecotype is different among natural regions. This study has proven with conviction that earthworm population structure varies depending on the biogeographical and pedobiological factors present within any respective terrestrial ecosystem.

scholarly journals The Sediment Selectivity of Perinereis aibuhitensis Larvae: Active or Passive?

2021 ◽  
Vol 8 ◽  
Author(s):  
Jinghui Fang ◽  
Wei He ◽  
Shan Meng ◽  
Zengjie Jiang ◽  
Jianguang Fang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Habitat ◽  
Organic Matter Content ◽  
Experimental Period ◽  
Matter Content ◽  
Active Selection ◽  
Sediment Types ◽  
Significant Difference ◽  
Perinereis Aibuhitensis ◽  
Sampling Times

The selectivity of Perinereis aibuhitensis larvae on different sediment types was studied using an experimental behavioral device in the lab. There were six types of sediment with different organic matter content: 2.19, 2.30, 2.86, 3.25, 3.51, and 5.52%. The results indicated significant differences in the six treatments’ organic matter content (p < 0.05). When the P. aibuhitensis larvae initially attached to the sediment, the larvae’s density showed no significant difference among the six treatments. The density of larvae decreased gradually during the experimental period. It increased with the increasing organic matter content in sediment at every sampling time, but there was no significant difference (p > 0.05). The larvae’s specific growth rate in the first month was significantly higher than those in the second and third months (p < 0.05). The mortality showed no significance at different sediments in equal sampling times, but the mortality was lower in high organic matter content sediments. This study showed that the P. aibuhitensis larvae did not make an active selection; random selection happened when initially attached to the sediment with different organic matter contents. Higher organic matter content in the sediment was more conducive to larvae survival, and the organic matter content is the limitation factor on the mortality and the density. The different densities in the natural habitat of P. aibuhitensis might occur due to the passive selection by the environment.

Litter accession and accumulation in a Melaleuca quinquenervia (Cav.) S.T. Blake wetland in south-eastern Queensland

1994 ◽  
Vol 45 (8) ◽  
pp. 1509 ◽  
Author(s):  
M Greenway
Keyword(s):  
Seasonal Pattern ◽  
Organic Matter Content ◽  
Matter Content ◽  
Melaleuca Quinquenervia ◽  
Nitrogen And Phosphorus ◽  
High Accumulation ◽  
Litter Accumulation ◽  
South Eastern ◽  
Leaf Litterfall ◽  
Significant Difference

Litterfall and litter accumulation were investigated over two years in a Melaleuca quinquenewia wetland in south-eastern Queensland. In 1992, a seasonally wet year, litterfall was 809 � 135 g m-2 yr-1 at the floodplain site and 764 �192 g m-2 yr-1 at the riparian site, of which Melaleuca leaf litter made up 65% and 56% respectively. Litterfall was significantly lower and more variable in 1993, a drought year, being 725�106 g m-2 and 675 � 216 g m-2 year-1. There was a distinct seasonal pattern, with peak leaf litterfall occurring in spring in 1992 but extending into summer in 1993. Melaleuca leaf fall was significantly lower in 1993, possibly because drought conditions caused greater leaf longevity. Litter accumulation on the forest floor was 3457 g m-2 at the floodplain site and 2320 g m-2 at the riparian site; there was no significant difference between years, although the organic matter content of the litter was lower in 1992, possibly as a result of leaching during flooding. Carbon content decreased with decreasing particle size of the litter, whereas nitrogen and phosphorus increased. There was no evidence to suggest leaching of nitrogen or phosphorus, and the high C: N: P ratios indicate slow rates of litter decay. The high accumulation of litter mass suggests that these woody wetlands may function as nutrient sinks.

scholarly journals Nitrogen Transformation Processes Taking Place During the Intensive Phase of Composting

2002 ◽  
Vol 51 (1-2) ◽  
pp. 157-166
Author(s):  
László Alexa ◽  
Gy. Füleky
Keyword(s):  
Raw Materials ◽  
Organic Matter Content ◽  
Nitrogen Transformation ◽  
Matter Content ◽  
N Losses ◽  
Total N ◽  
Intensive Phase ◽  
Significant Difference ◽  
Order Of Magnitude ◽  
Transformation Processes

N transformation processes taking place during the intensive phase of composting were analyzed for characteristic compost raw materials in an adiabatic composting bioreactor by analyzing composts (in various stages of maturity), emitted gases and leakage water.  Temperature exhibited a similar curve for all raw materials, with a gradual decrease in compost temperature from day 11-13 on. Measurements of NH 3 indicated a significant difference between the various raw materials, sometimes amounting to an order of magnitude, in the quantitative data of NH 4 volatilization. Analysis of leakage water indicated that ammonification and nitrification processes could be traced satisfactorily, but the quantity of leakage water formed in the adiabatic drum composter and the associated N losses were negligible compared to the total N cycle of compost formation. Analysis of the composts showed that the organic matter content of the samples declined during composting as the result of biodegradation.

scholarly journals Initial limnological observations at five small lakes in southern Pacific Costa Rica

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Sally P. Horn ◽  
Erik N. Johanson ◽  
Kurt A. Haberyan ◽  
Mathew S. Boehm ◽  
Jessie L. Johanson ◽  
...  
Keyword(s):  
Costa Rica ◽  
Environmental History ◽  
Global Climate ◽  
Sediment Cores ◽  
Organic Matter Content ◽  
Plant Macrofossils ◽  
Matter Content ◽  
Radiocarbon Dates ◽  
Natural Lakes ◽  
Lake Formation

Costa Rica has hundreds of lakes, many of which have never been described or sampled by limnologists. Here we summarize initial observations of five small (0.2–1.7ha) lakes located at low elevation (365–490m) in the cantón of Buenos Aries. We collected basic limnological data and samples during visits in 2013 and 2014, and compiled environmental and archaeological data for their surroundings as a contribution to the documentation of lake diversity in Costa Rica, and to support parallel investigations of indicators of environmental history preserved in the sediments of the lakes. Lagunas Carse, Los Mangos, Danta, and Ojo de Agua all appear to owe their origin to landslide events, while Laguna Junquillo is an artificial impoundment. Radiocarbon dates on plant macrofossils near the bases of sediment cores from three of the natural lakes provide minimum ages for lake formation; results indicate that Laguna Los Mangos formed over 4 100 years ago, while Laguna Danta formed prior to 1 320 CE and Laguna Carse formed ca. 1 550 CE, near the time of the Spanish Conquest. More than two dozen archaeological sites are located within 1–3Km of the natural lakes, documenting pre-Columbian human occupation and likely use of lake resources. Lake water temperatures and water chemistry were in keeping with observations at lakes throughout Costa Rica. All five lakes are probably polymictic lakes that turn over frequently; none evinced stratification. The surface lake sediments showed similar organic matter content (22,1–28,8%), with values falling near the middle of the range of lakes previously sampled in Costa Rica. Phytoplankton samples included taxa previously reported from small lowland lakes, but differed between lakes and included dominant taxa that were subdominant or uncommon at other lakes surveyed. Our investigation adds to knowledge of lake characteristics and diversity in Costa Rica, and provides benchmarks for assessing future changes in these lakes and their watersheds resulting from human activity, natural disturbances, and regional and global climate change.

scholarly journals Assessment of Soil Properties Under Different Land Use Types in Olokemeji Forest Reserves in Ogun State Southwestern Nigeria

2020 ◽  
Vol 7 (3) ◽  
pp. 73-84
Author(s):  
OLUWATOYIN OPEYEMI AKINTOLA ◽  
ADEWUNMI IDAYAT BODEDE ◽  
MICHAEL MICHAEL ◽  
AYODEJI GIDEON ADEBAYO ◽  
OLAWALE NUREAN SULAIMAN
Keyword(s):  
Soil Properties ◽  
Environmental Sustainability ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Matter Content ◽  
Natural Forest ◽  
Available Phosphorus ◽  
Forest Plantation ◽  
Southwestern Nigeria ◽  
Significant Difference

Knowledge of soil properties is essential for environmental sustainability for any forest reserve or plantation. The physical and chemical properties of soil under three different land uses was investigated to assess the nutrient and fertility status of the soils. Fifteen soil samples, each collected from different locations within the natural forest, plantation and farm land were analyzed for soil texture, bulk density, porosity, pH, organic carbon, organic matter content, total nitrogen, available phosphorus, Na, K, Ca, Mg, Zn, Cu, Fe and Mn. Texturally, the soils were loamy, loamy sand and sandy loamy in the natural forest, plantation and farmland respectively. There was a significant difference between the three different soils in composition and texture.

scholarly journals Heavy Metal Content and Physico-Chemical Analyses of Soils under the Litter of some Medicinal Taxa in the Luki Biosphere Reserve, Democratic Republic of the Congo

2021 ◽  
pp. 19-35
Author(s):  
Florent Biduaya Mukeba ◽  
Myriam Mukadi Ngondo ◽  
Nazaire Kabemba Kadima ◽  
Prince Bofati Ilonga ◽  
Patrick Kayembe Bibasuya ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Metal Content ◽  
Organic Matter Content ◽  
Biosphere Reserve ◽  
Matter Content ◽  
Heavy Metal Content ◽  
Significant Difference ◽  
Canadian Council ◽  
Cadmium Lead

Aim: The aim of this study was to compare the texture, mineral element and heavy metal content of the soil under the litter of different selected species in relation to the plan of their pedogenesis. Methods: The granulometric analysis of the various samples based on laser diffraction, measurements of Total Nitrogen and Total Organic Carbon were performed using the Elemental Analyzer, the Organic Matter content is estimated by the loss of ignition method using a Salvis furnace, In order to estimate the CaCO3 content. The same samples were heated in the oven at 1000°C for 60 minutes and reweighed. The carbonate content is estimated by the loss in mass during this second firing, multiplied by 2.274 which is the molecular weight ratio between CaCO3 and CO2. The heavy metal and mineral composition was evaluated by ICP-AES and AAS. Results: The granulometric analyses show a sandy texture, according to the FAO classification. The organic matter content thus observed in the soils under the litter of these four species did not show any significant difference. The concentration of major mineral elements recorded in soils under the litter of Blighia welwitchii, Oncoba welwitschii, Zanthoxylum gilletii and Harungana madagascariensis did not show any significant difference. However, potassium, phosphorus, and magnesium have a high concentration compared to calcium and sodium. This study showed that the levels of cadmium, lead, arsenic and aluminum in the various samples of litter soils of all plant species including nickel for B. welwitschii are above the standards set by the Canadian Council of Ministers of the Environment for soil quality. Pollution factors for aluminum are the highest. This indicates that aluminum is the most polluting metal. The low pollution factors for lead and nickel are due to the low fixation of these metals by soils. Conclusions: Our study took place in the Luki Biosphere reserve and showed that the different soils under litter are polluted by very toxic and persistent heavy metals such as cadmium, lead, aluminum, arsenic and nickel. This study has revealed new aspects of heavy metal pollution. This pollution represents a serious threat to the environment in general and to humans in particular through the food chain.

scholarly journals Total mercury concentrations in fish from Urrá reservoir (Sinú river, Colombia). Six years of monitoring

2015 ◽  
pp. 4754-4765 ◽  
Author(s):  
José Marrugo-Negrete ◽  
Amado Navarro-Frómeta ◽  
Javier Ruiz-Guzmán
Keyword(s):  
Water Quality ◽  
Fish Species ◽  
Total Mercury ◽  
Organic Matter Content ◽  
Matter Content ◽  
Trophic Levels ◽  
Steady Increase ◽  
Fish Length ◽  
Tissue Water ◽  
Fish Food

ABSTRACTObjective. The aim of this study was to monitor the total mercury (T-Hg) concentrations in fish from the Urrá reservoir, after impoundment. Materials and methods. Five fish species at different trophic levels were sampled from 2004 to 2009 and analyzed by cold-vapor atomic absorption spectroscopy for T-Hg concentrations in muscle tissue. Water quality parameters were evaluated. Results. The highest (1.39±0.69 μg/g ww) and lowest (0.15±0.02 μg/g ww) T-Hg concentrations were detected in Hoplias malabaricus (piscivorous) and Cyphocharax magdalenae (iliophagous/detritivorous) respectively, whereas Leporinus muyscorum (omnivorous) had an intermediate level (0.40±0.11 μg/g ww). The organic matter content in the water increased with time and depth, whereas dissolved oxygen and pH decreased. A covariance analysis (with fish length as a covariate) shows a steady increase of T-Hg levels in all the studied species after impoundment. Conclusions. The T-Hg concentrations in the evaluated fish species, increased after impoundment. The water quality variables showed conditions favoring Hg methylation and its biomagnification, this last was evident in the fish food chain of the reservoir.

scholarly journals Oxalate Carbonate Pathway—Conversion and Fixation of Soil Carbon—A Potential Scenario for Sustainability

2020 ◽  
Vol 11 ◽  
Author(s):  
Shameer Syed ◽  
Viswanath Buddolla ◽  
Bin Lian
Keyword(s):  
Soil Carbon ◽  
Forest Soil ◽  
Carbon Capture ◽  
Carbon Sink ◽  
Global Climate ◽  
Low Cost ◽  
Organic Matter Content ◽  
Matter Content ◽  
Capture Process ◽  
Degrading Bacteria

It is still an important aspect of global climate research to explore a low-cost method that can effectively reduce the increase of CO2 concentration in the global atmosphere. Oxalotrophic bacterial communities exist in agricultural or forest soil with ubiquitous oxalate as the only carbon and energy source. When soil oxalate is oxidized and degraded, carbonate is formed along with it. This process is called the oxalate carbonate pathway (OCP), which can increase soil inorganic carbon sink and soil organic matter content. This soil carbon sink is a natural CO2 trapping system and an important alternative if it is properly managed for artificial sequestration/storage. As the main driver of OCP, the oxalate degrading bacteria are affected by many factors during the oxalate conversion process. Understanding this process and the synergy of oxalogenic plants, saprophytic decomposers, and oxalotrophic bacteria in agricultural or forest soil is critical to exploiting this natural carbon capture process. This article aims to provide a broader perspective of OCP in CO2 sequestration, biomineralization, and elemental cycling.

scholarly journals Long and Midterm Effect of Conservation Agriculture on Soil Properties in Dry Areas of Morocco

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Malika Laghrour ◽  
Rachid Moussadek ◽  
Rachid Mrabet ◽  
Rachid Dahan ◽  
Mohammed El-Mourid ◽  
...  
Keyword(s):  
Arid Regions ◽  
Organic Matter Content ◽  
Soil Surface ◽  
Conservation Agriculture ◽  
Conventional Tillage ◽  
Matter Content ◽  
No Tillage ◽  
Tillage Systems ◽  
Soil Organic Matter Content ◽  
Significant Difference

In Morocco, conservation agriculture, particularly no tillage systems, has become an alternative strategy to mitigate land degradation caused by conventional tillage in semiarid to arid regions. This paper is based on behaviour to tillage treatments of two Vertisols in Morocco. After 11 years of testing, soil organic matter content results showed a significant difference (P<0.05) only at soil surface (0–10 cm) in favour of no tillage and a variation of 30% at this depth. The results obtained after 32 years of testing showed a significant soil profile difference (P<0.05), up to 40 cm under no tillage compared to conventional tillage, and a variation of 54% at 5–10 cm. For total nitrogen, there was no significant effect between no tillage and conventional tillage at the soil surface after 11 years unlike the result obtained after 32 years. There are no significant differences in bulk density between tillage treatments at soil surface for both sites. The measurement of soil structural stability showed a significant effect (P<0.05) for all three tests and for both sites. This means that no tillage helped Vertisols to resist different climatic constraints, preserving environmental soil quality.

Sign in / Sign up

Export Citation Format

Share Document