Open Journal of Ecology
ISSN / EISSN : 2162-1985 / 2162-1993
Current Publisher: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 486
Latest articles in this journal
Open Journal of Ecology, Volume 11, pp 1-23; doi:10.4236/oje.2021.111001
Clarifying the necessary conditions for the emergence of payments for ecosystem services (PES) and the situational variables that affect PES is the basis for their interpretation, prediction, and selection. This article proposes an analytical framework for the emergence of PES and argues that the key to determining whether PES can occur and whether a selected PES program is appropriate is to evaluate the net gain. When payers anticipate that a PES program will provide a satisfactory number of ES and a net gain over the opportunity cost and will cover all costs, it is assumed that the program will be implemented. When it is difficult to accurately evaluate the net gain of PES, the situational variables that affect the costs and benefits need to be examined. The group characteristics, ES characteristics, spatial and temporal contacts between the suppliers and demanders, correlation with private goods and additionality are important situational variables that affect the emergence and choice of PES.
Open Journal of Ecology, Volume 11, pp 52-63; doi:10.4236/oje.2021.111005
We examined the relationship between seasonal livestock grazing (late summer and late winter) and the abundance of two ant species, Dorymyrmex insana and Forelius pruniosus, on three types of plants (mesquite shrubs, snakeweed sub-shrubs, and mixed grasses) dominated by black grama (Bouteloua eriopoda). Stocking rates were adjusted to remove 75% of the available forage. Since Chihuahuan Desert grasslands are not in transition to shrublands, the grasses and some herbaceous plants are the only available forage. We hypothesized that neither rainfall nor cattle grazing would affect the abundance of these ants on mesquite (Prosipis glandulosa) or snakeweed (Gutierrezia sarothrae). Linear regressions of monsoon rainfall on mesquite (Prosopis glandulosa) produced an r2 nearly equal to that with the annual precipitation. Monsoon rainfall on the evergreen sub-shrub, Gutierrezia sarothrae, resulted in June-July rainfall accounting for 47% - 83% of the variation in densities of D. insana on snakeweed. The number of D. insana was more than double the number of F. pruinosus on grasses, mesquite, and snakeweed. There were significant reductions in the abundance of F. pruinosus on the grass in the grazed plots; each year the plots were grazed. There were no significant effects of grazing on the abundance of either of the ant species sampled from G. sarothrae canopies. There were significantly fewer D. insana on mesquite in summer grazed plots than on P. glandulosa in winter grazed and ungrazed plots in the second and third years of grazing. Pre-grazing effects were compromised by the high annual (more than double) precipitation.
Open Journal of Ecology, Volume 11, pp 41-51; doi:10.4236/oje.2021.111004
This study aimed to assess the impact of the Nile flood with special reference to turbidity on the food chain in Lake Nasser water as one of the largest man-made lakes in Africa before the flood (BF) and after the flood (AF) seasons. To achieve that aim, subsurface water samples were collected from 11 sampling stations along the lake before and after the flood for analyzing the water turbidity, total suspended solids, and total phosphorus, as well as chlorophyll-a and zooplankton to represent the food chain in the lake. Results showed an increase in water turbidity after the flood than that before the flood. Total suspended solids concentration displayed a similar trend as water turbidity. Chlorophyll-a concentration increased in AF all over the lake except at the entrance of the lake, as compared to the BF season. Zooplankton count was represented by copepods, cladocerans, and rotifers with the dominance of copepods in AF and rotifers in BF. The density of zooplankton was higher in the AF than the BF season. The negative impact of flood turbidity had appeared on crustacean organisms.
Open Journal of Ecology, Volume 11, pp 24-31; doi:10.4236/oje.2021.111002
Climatic conditions affect the richness of ants resulting in number variation throughout the year. The ants present in the Neotropical system Acacia-Pseudomyrmex have been previously studied considering only one sampling season. In contrast, in this study we analyze the richness in two ant-acacia systems during the rainy and dry seasons. The study was carried out on a plot located in the state of Oaxaca, Mexico where 14 ant species, 3 mutualistic and 11 non-mutualistic were found, of which 2 represent new records for the state. Ant species number differed between ant-acacia species and between seasons. The highest richness was recorded in Acacia hindsii in both rainy and dry seasons, corresponding with a low-reward host. During the dry season, A. hindsii represents a highly valuable resource. This study shows that the neotropical system is much more dynamic than it has been previously considered and offers a valuable opportunity for subsequent ecological studies for a better understanding of this complex system.
Open Journal of Ecology, Volume 11, pp 32-40; doi:10.4236/oje.2021.111003
The richness of spider species on the foliage of Mexican ant-acacias in Los Tuxtlas (Veracruz), and Santiago Pinotepa Nacional (Oaxaca) was documented. A total of 11 species, grouped into five families were found; in Los Tuxtlas five species representing two families were identified, whereas in Santiago Pinotepa Nacional, the number of taxa was eight, belonging to five families. The richness of spiders in Santiago Pinotepa Nacional was higher than that found in Los Tuxtlas. In both locations Nephila clavipes Linnaeus and Eustala illicita O. Pickard-Cambridge, both from Araneidae, were found; these species had been previously reported as common inhabitants of Central American ant-acacias. The presence of E. illicita in Mexican myrmecophytic acacias was confirmed. A total of 10 species grouped into five families are reported for the first time inhabiting Mexican ant-acacias, increasing the richness of spider interactions documented in Mexico. This study showed that the occurrence of spiders in the Vachellia-Pseudomyrmex mutualism system has been overlooked and is likely more common than what has been reported until now. This opens an opportunity for the study of the evolution of spider-ant-plant interactions.
Open Journal of Ecology, Volume 11, pp 64-74; doi:10.4236/oje.2021.111006
Termites are the most serious pests of field and horticultural crops, forests, and wooden household furniture. In Hamelmalo Agricultural College (HAC) the infestation of termite is very high resulting in great destruction of crop plants and wooden office and dormitory furniture. The devastating attack of termites should be managed by using best and ecofriendly management method. The purpose of the study was to compare the effectiveness of manual destruction of mounds and killing of termite queen and king, chemical chlorpyrifos, seed and leaves extract of neem and Lantana (as separate experiment) and smoke on termite control. Termite mounds were selected randomly inside HAC compound. The materials used were hand hoe, spade, fork, water, 20 L jar and protective clothes. The treatments were replicated three times. The botanical treatments were prepared at 2 L of highly concentrated extracts per 20 L of water each. Chlorpyrifos was applied at 20 ml per 20 L of water. Dried woody plants were used for smoke treatment. Careful digging was done to avoid king escape and queen rupture and they were killed by burning. Among all, the mechanical destruction and killing of king and queen and chlorpyrifos resulted in a complete control of the termite population. Except in the mounds treated by chlorpyrifos, the activity of termite population was very active and they closed the opened galleries immediately after treatment even though there were dead termite castes in all treatments. Living termite castes were counted by taking a medium size spade of broken mound pieces. The highest count was recorded from mounds treated by smoke. After two weeks the queen and king in every treatment mound were cheeked and killed for those who were alive. Except by the chlorpyrifos and manual destruction of mound (king and queen were killed before) all the royal families were alive and killed. Controlling of termite population in the field (outside their mound) is not possible due to the hidden foraging activity of termites, environmental safety from chemicals and the high egg laying potential of the queen. Finding the best alternative to control from their source mound for the mound building termites resulted in effective control of the population by manual destruction of mounds and killing of queen and king and chlorpyrifos. By the side effect of chlorpyrifos to untargeted organisms and the time consuming and laborious method of manual destruction of mounds, selection to the best from these two control measure is almost the same.
Open Journal of Ecology, Volume 10, pp 1-21; doi:10.4236/oje.2020.101001
Water is life and access to clean drinking water is a fundamental human right. For human health, drinking water standards and guidelines have been developed to ensure their quality. Waterborne parasites are a great challenge and cause many diseases for humans. Thus, continuous monitoring of drinking water from the competent authorities in search of pollutants is required. The safety of drinking water for the growing population can be ensured by the correct use of water treatment technologies. Cryptosporidium is the first parasite to cause concern to health officials in the world. Also, Naegleria fowleri causes fatal cerebral infection, Acanthamoeba species that cause both cerebral and corneal disease; and Giardia which has heightened world concerns because of its severity. This study is based on highlighting on drinking water quality guidelines and standards published by the World Health Organization and some countries, especially Egypt. A growing concern globally after the scientists revealed the effects of polluted drinking water. So, a large number of the population is at risk of water pollution for the purpose of human access to clean drinking water and other uses.
Open Journal of Ecology, Volume 10, pp 22-35; doi:10.4236/oje.2020.101002
Lake Victoria the second largest fresh water body in the world located in East Africa is a shared resource between Kenya, Tanzania and Uganda and enjoys a wide range of streams and rivers from as far as Burundi and Rwanda. The lake has environmentally undergone physical, chemical and biological changes in the last four decades, particularly rise in its trophic condition and decline in oxygen level, which affects the water quality and fish population dynamics. This study therefore set out to determine the quality of water in selected fishing beaches of Lake Victoria, Kenya with a view to report the possible pollution levels. pH was highest at Nyamasari and Kotieno (9.3 ± 0.1) and lowest at Nyachebe and Kichinjio (7.08 ± 0.1) whereas temperature was highest at Nyamasari (29.5°C ± 0.0°C) and lowest at Kichinjio (23.4°C ± 0.2°C). DO was highest at Kotieno (10.3 ± 0.2 mgL) and lowest at Seka (2.4 ± 0.1 mgL). Turbidity was highest at Uyoga (125.5 ± 0.90 NTU) and lowest at Osieko (2.7 ± 0.1 NTU). Ammoniacal nitrogen was highest at Dunga (1278.3 ± 0.8 μ∙gl-1) and lowest at Nyamasari (12.4 ± 0.8), all a factor of human activities, lake substratum and effluents from rivers and surface runoff. All parameters assessed showed significant differences across sampling sites and depth except pH which did not vary significantly with distance from lakeshore. Further, all parameters did not show a clear pattern with respect to distance from the lakeshore possibly due to adequate mixing in the gulf. There is a need for further water quality monitoring by seasons to inform policy decisions towards sustainable lake exploitation.
Open Journal of Ecology, Volume 10, pp 768-777; doi:10.4236/oje.2020.1012047
The distribution, diversity, and abundance of sea cucumbers in intertidal zones of Aurora were studied from February to June 2013 to obtain baseline data. A one-hour timed-search survey covering an approximate one kilometer over a ten-meter wide area was conducted in six coastal municipalities to obtain a comprehensive list of sea cucumber species found in the zones. Only four sampling stations (Baler, Dipaculao, Dilasag, and Dingalan) were selected for belt transect survey, 50 × 50 m, based on the availability of coralline, sandy, muddy sand, and rocky habitats which were laid perpendicular and parallel to each intertidal zone. Timed-search survey revealed a total of 15 species of sea cucumbers distributed among two Orders (Order Aspidochirotida and Order Apodida) and four Families (Family Holothuriidae, Family Stichopodidae, Family Synaptidae, and Family Chirotidae) were recorded. Synapta maculata is most common and has widespread distribution. Belt-tranect surveys showed Holothuria leucospilota is among the most frequently occurring species both during day time (58%) and night time (75%). The Dilasag sampling station had the most diverse species (0.71) while the Dipaculao sampling station had the densest species of Holothuria leucospilota (10,014 in∙ha−1) and abundant (95.91%) species.
Open Journal of Ecology, Volume 10, pp 200-224; doi:10.4236/oje.2020.104014
Long term data record (1944-2018) of climatological conditions in the Lake Kinneret and its watershed ecosystems was statistically evaluated and the impact of Anthropogenic operations was included as well. Precipitation input source is obviously uncontrolled natural component whilst the other three regional water outflows pathways are under anthropogenic control: Evapo-transpiration (ET), Runoff and underground flows. Indications for climate change expressed as air warming with consequences on regional (watershed and the lake) water resources and consumption capacities policy in the drainage basin and in the Lake are discussed. The decline of air temperature from 1940 to 1970s is probably due to a change in the Albedo effect. After the decline air temperature was twisted towards elevation. Climate change caused a decline in rainfall, followed by a reduction of Jordan and other river discharges and underground flows, accompanied by a decline of WL. With respect to climate change, water allocation for agricultural consumption was shrunk.