Earthworm population density and diversity in different-aged urban systems

In the context of global warming and rising sea levels, as urbanization continues to increase, the risk situation of urban systems facing floods has become more severe. Therefore, we constructed a vulnerability assessment model for urban flood disasters in Jiangsu Province, focusing on using GIS technology to classify the land use of each city in Jiangsu Province for supervised learning. We also established a flood disaster vulnerability model to evaluate the Vulnerability of 13 cities in Jiangsu Province. Evaluation and analysis of the changes in land use vulnerability use flood disasters in Jiangsu Province from 2000 to 2020. The results show that from 2000 to 2020, the Vulnerability to flooding disasters is on the rise as a whole. Yancheng has the lowest average Vulnerability to flooding disasters due to the low population density and high greening rate in the built-up area. On the other hand, Nantong City has the most heightened average flood vulnerability due to excessive population density. The low greening rate in built-up areas has led to a worsening of flood vulnerability. Suggestions have been made to reduce the Vulnerability of urban floods in Jiangsu Province, such as vigorously developing the local economy, reasonably adjusting the rate of urbanization, and building drainage infrastructure.

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An Assessment of Earthworm Population Density of different Habitat Types in a Mango Cultivation Region of Palakkad District, Western Ghats

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.33677 ◽

2021 ◽

Vol 9 (4) ◽

pp. 585-590

Author(s):

Chandini P K

Keyword(s):

Population Density ◽

Western Ghats ◽

Habitat Types ◽

Earthworm Population

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Influence of cropping on the population of a native earthworm and consequent effects on hydraulic properties of vertisols

Soil Research ◽

10.1071/sr9950995 ◽

1995 ◽

Vol 33 (6) ◽

pp. 995 ◽

Cited By ~ 29

Author(s):

JJ Friend ◽

KY Chan

Keyword(s):

Population Density ◽

New South ◽

Soil Surface ◽

Infiltration Rate ◽

Shrinkage Cracks ◽

South Wales ◽

Natural Pasture ◽

Earthworm Population ◽

Moisture Conditions ◽

Brown Clay

Population density of Heteroporodrilus mediterreus, a large native earthworm found on the Mitchell grassland (Astrebla lappacea) on the Vertisol plains near Walgett, New South Wales, was investigated at two sites (brown and grey clays). Maximum earthworm activity at the soil surface layer was observed during winter (July/August) corresponding to more favourable soil moisture conditions. The highest earthworm population density (7.5 m-2) and biomass (0.89 t ha-1) were detected at the brown clay site under natural pasture. Populations were much lower (by two thirds in the brown clay) and the proportion of immature worms was much higher in the cropped soils than in the pasture soils. Current wheat cropping practices involving long fallowing and excessive cultivation during the period when earthworms are active at the surface are the possible causes of the reduction in population. Disc permeameter measurements compared with infiltration through single earthworm holes showed that the earthworm channels contributed significantly to the movement of water into the subsoil. Their persistence under wet conditions, even after closure of shrinkage cracks, suggests they are also important in maintaining subsoil aeration. Significant reductions in sorptivity and infiltration rate were observed in the cropped soils.

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TERRITORIAL AND SPATIAL ORGANIZATION: WORLD EXPERIENCE AND TRENDS

Urban development and spatial planning ◽

10.32347/2076-815x.2021.77.73-86 ◽

2021 ◽

pp. 73-86

Author(s):

Denis Vishnevsky

Keyword(s):

Population Density ◽

Urban Development ◽

Spatial Organization ◽

Urban Systems ◽

The Sustainable Development ◽

Large Cities ◽

The World ◽

The Face ◽

Demographic Processes ◽

Social Environmental

The article analyzes the current trends in urban development systems. As a result of identifying the main problems of urban development, groups of issues were formed, in particular, economic, social, environmental, social, psychological and technological aspects. Each of these blocks significantly affects the comfortable living of the population of large cities, as well as affects the sustainable development of territories. Problems of overpopulation, which create new socio-economic challenges and increase man-made impact on ecosystems, are the main problems of development of areas that have become the cause of other problematic aspects. The article analyzes the demographic processes of different regions of the world and their impact on the formation of megacities. It is determined that the largest cities in the world are formed in countries with the largest population and high population density. An analysis of the largest cities in the world by population, location and population density is given. according to the conducted analysis the preconditions defining tendencies of development of megacities are formed. In accordance with these prerequisites, a projection of the development of megacities by regions of the world depending on the current situation, factors influencing the development of urban systems and analysts' forecasts. According to these forecasts, urban trends in different regions of the world are analyzed. The map of the largest megacities of the world on the basis of which their territorial zoning is carried out is presented. The results of the study can be used to determine the prospects for the development of urban systems, finding ways for further urban development in the face of new challenges.

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Characterization of Earthworms (Lumbriscus terestris) Population Under Several Area of Shallots Cultivation

Jurnal Lahan Suboptimal ◽

10.33230/jlso.9.2.2020.508 ◽

2020 ◽

Vol 9 (2) ◽

Author(s):

M. Anang Firmansyah ◽

Andy Bhermana

Keyword(s):

Population Density ◽

Soil Ph ◽

Rainy Season ◽

Land Suitability ◽

Land Evaluation ◽

Limiting Factor ◽

Peat Soils ◽

Earthworm Population ◽

Earthworm Populations

Firmansyah MA, Bhermana A. 2020. Characterization of earthworms (Lumbriscus terestris) population under several area of shallots cultivation. Jurnal Lahan Suboptimal : Journal of Suboptimal Lands 9(2): 208-217.In General, the problem of shallot commodities development was still used common farming without considering land suitability and other specific soil condition including aspect cultivation. The objective of this study was to clasify several lands characteristics for shallots cultivation and to observe earthworm (Lumbriscus terrestris) population based on their land suitability classes. The methodology used was land evaluation approach and field observation. This study was performed during rainy season in 2018 at three locations with different soils, namely, peat soils/Histosol (IST), buried soil of Quartzipsamment above peat soils (ENT), and dry land of Dystropept (EPT). The population of earthworms is obtained by digging up an area of 1 m2 with depth of 20 cm at in four places of location of study. The calculation of earthworms is conducted by hand sorting. The results showed that the highest land suitability class at EPT S3tr, rt, nr, while for other locations are not suitable. The location of IST is classified into N3fb with several limiting such as flooding hazard during rainy season, while for ENT location, classified into Nrt, limiting factor is rough texture. High suitability class is not identical with high earthworm population density. Cultivation aspect that is able to increase soil pH become neutral condition and lower pesticide application affect earthworm populations. ENT locations that have neutral soil pH with lower pesticides applcation have the highest earthworm populations. Earthworm population density from high to low involve ENT> IST> EPT or 74> 33> 31 tails/m2.

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EARTHWORM COMMUNITIES (OLIGOCHAETA, LUMBRICIDAE) OF PINE FORESTS AND SMALL FOLIAGE FORESTS IN THE FOREST-STEPPE OB’ REGION

Forest science issues ◽

10.31509/2658-607x-202141d20 ◽

2021 ◽

Vol 1 (4) ◽

pp. 1-20

Author(s):

S.A. Ermolov ◽

Keyword(s):

Population Density ◽

Species Composition ◽

Chemical Properties ◽

Pine Forests ◽

Ecosystem Functions ◽

Soil Parameters ◽

Forest Steppe ◽

Layer By Layer ◽

Soil Macrofauna ◽

Earthworm Population

Earthworms form an essential group of soil macrofauna that performs a number of ecosystem functions in forests. Studies of the species composition and population density of earthworms were conducted in many regions of Russia; however, the fauna of Lumbricidae of Novosibirsk area remained unexplored for a long time. The objective of this work is to carry out a comparative analysis of earthworm population in coniferous and small foliage forests of the forest-steppe Ob region (Novosibirsk area) and to identify the correlation between the fauna composition and the basic physical and chemical properties of the soil. The study was conducted in pine forests and birch-aspen forests. The main method of registration was layer-by-layer excavation of soil with hand sorting of soil samples and analysis of forest deadwood. Some soil parameters were also measured. Data of the species composition and population density of earthworms for each habitat are given. The studied habitats were classified according to the ratio of the earthworm living forms. It was found that soil humidity is the most significant factor for the group of epigeiс and epi-endogeiс species. The diversity of epigeiс and epi-endogeiс earthworm species in forests is largely supported by deadwood. The Asian subspecies Eisenia nordenskioldi nordenskioldi was subjected to morphometric analysis confirming its characteristic polymorphism.

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FIRST RECORD OF CINARA (CINARA) CEDRI CEDRI MIMEUR (HEMIPTERA APHIDIDAE) IN BULGARIA

Redia ◽

10.19263/redia-104.21.17 ◽

2021 ◽

Vol 104 ◽

pp. 161-165

Author(s):

GEORGI GEORGIEV ◽

MARGARITA GEORGIEVA ◽

KATIA TRENCHEVA ◽

PLAMEN MIRCHEV ◽

MIHAIL KECHEV ◽

...

Keyword(s):

Health Status ◽

Population Density ◽

First Record ◽

Urban Systems ◽

High Population ◽

High Population Density ◽

Sooty Mold ◽

Forest Nurseries ◽

Old Trees ◽

First Time

In 2017, damages caused by aphids were observed for the first time on Cedar trees in Bulgaria. In 2020, apterae specimens of Cinara (Cinara) cedri cedri were collected and identified on Cedrus atlantica and C. deodara in seven localities both on young trees in forest nurseries and on old trees in plantations or in green urban systems. The pest appears to be a serious threat to the health status and decorative characteristics of Cedar trees. In case of high population density, the needles are covered with large honeydew secretions and sooty mold.

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