scholarly journals Modification of Topsoil Physico-Chemical Characteristics and Macroinvertebrates Structure Consecutive to the Conversion of Secondary Forests into Rubber Plantations in Grand-Lahou, Côte d’Ivoire

2018 ◽  
Vol 8 ◽  
pp. 1235-1255
Author(s):  
N'dri Kouadio Julien ◽  
Kévin Kouadio N’Guessan
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Rainy Season ◽  
Secondary Forest ◽  
Dry Season ◽  
Chemical Characteristics ◽  
Secondary Forests ◽  
Rubber Plantations ◽  
Physico Chemical ◽  
Soil Macroinvertebrates

The objective of this investigation was to assess the modifications of topsoil physico-chemical characteristics and macroinvertebrates structure consecutive to the conversion of secondary forests into rubber plantations and how these change with the aging of the plantations and the season. The sampling design was constituted of four treatments: secondary forest referred to as baseline land use, 7-, 12- and 25 year old rubber plantations. Three replications per land use type were randomly established in each of the selected treatments, thus totaling 12 sampling areas. On each sampling area, a 40 m transect was established. The litter dwelling and topsoil (0-10 cm) macroinvertebrates were sampled, respectively, by using the pitfall traps and monoliths (50 cm × 50 cm × 10 cm) following the Tropical Soil Biology and Fertility method. The soil physical and chemical parameters were measured along the 40 m transect. The results showed that the conversion of secondary forest into plantations was characterized by a modification of the density of soil macroinvertebrates (dry season: -50 and -24% vs. rainy season: -61 and +32%), taxonomic richness of soil macroinvertebrates (dry season: +7 and -14% vs. rainy season: -21 and -14%), water content (dry season: -41 and -5% vs. rainy season: -62 and -31%), bulk density (dry season: +6 and -3% vs. rainy season: +33 and +29%), soil organic carbon (dry season: -73 and -59% vs. rainy season: -67 and -51%) and total nitrogen (dry season: -68 and -58% vs. rainy season: -64 and -52%), respectively, after about 7 and 25 years of conversion. The restoration processes did not cause significant changes in the soil physico-chemical and biological characteristics after 25 years of forests conversion. However, the study highlighted the improvement in the soil ecological quality due to a reduction in soil degradation, and an increase in the density of macroinvertebrates (+235%), taxono mic richness (+9%), water content (+84%), soil organic carbon (+50%) and total nitrogen (+33%) in the 25 year old plantations compared to the 7 year old plantations.

scholarly journals Edaphic characteristics and environmental impact of rubber tree plantations on soil mite (Acari) communities

Acarologia ◽  
2018 ◽  
Vol 58 (4) ◽  
pp. 951-962
Author(s):  
Julien K. N’Dri ◽  
Pacôme K. Pokou ◽  
Fabrice A. Séka ◽  
Rodolphe A. G. N’Da ◽  
Jan Lagerlöf
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Environmental Impact ◽  
Water Content ◽  
Secondary Forest ◽  
Rubber Tree ◽  
Secondary Forests ◽  
Rubber Plantations ◽  
Soil Mites ◽  
Land Use Types

The objective of the investigation was to determine the response of different taxa of mites across the land use types and demonstrate that soil mites could be used as an indicator of environmental change after the conversion of secondary forests into rubber plantations. The sampling was performed during the dry season on 12 sampling areas, consisting of four land use types: secondary forests, 7-year-old rubber plantations, 12-year-old rubber plantations, and 25-year-old rubber plantations, with three replications of each treatment. Soil cores were sampled along a 40 m transect with a steel corer. The soil mites were extracted using modified Berlese-Tullgren funnels during a 10 day period. Soil physico-chemical parameters were measured on each sampling area. The conversion of secondary forests into rubber plantations was characterized by a modification of the mean values of mite density (+103 and +262%), species richness (-11 and +32%), water content (-41 and -5%), bulk density (+6 and -3%) and soil organic carbon (-73 and -59%) respectively, after 7 and 25 years of conversion. The density of mites, species richness and soil water content increased with the aging of the rubber plantations, demonstrating an improvement in soil ecological quality and environmental conditions. These results are confirmed by the values of the Maturity Index of Gamasid mites, which increased with the increasing age of rubber plantations. In other words, the severity of environmental impact decreased with the aging of the rubber plantations and was ranked as follows: 25-year-old rubber plantations < secondary forest < 12-year-old rubber plantations < 7-year-old rubber plantations. The Maturity Indexes estimated that 25-year-old rubber plantations (0.84) and in secondary forests (0.74) are relatively similar and characterize stable habitats, which are potentially dominated by Gamasid species with K selection.

STUDI BIONOMIK VEKTOR MALARIA DI KECAMATAN KALIBAWANG, KULONPROGO

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Sardjito Eko Windarso dkk
Keyword(s):  
Land Use ◽  
Malaria Vector ◽  
Rainy Season ◽  
Dry Season ◽  
Physical Factors ◽  
Mosquito Vector ◽  
Anopheles Species ◽  
Commercial Farming ◽  
Study Results ◽  
Dry And Rainy Seasons

The increasing of malaria cases in recent years at Kecamatan Kalibawang has been suspected correspond with the conversion of farming land-use which initiated in 1993. Four years after the natural vegetation in this area were changed become cocoa and coffee commercial farming estates, the number of malaria cases in 1997 rose more than six times, and in 2000 it reached 6085. This study were aimed to observe whether there were any differences in density and diversity of Anopheles as malaria vector between the cocoa and mix farming during dry and rainy seasons. The results of the study are useful for considering the appropriate methods, times and places for mosquito vector controlling. The study activities comprised of collecting Anopheles as well as identifying the species to determine the density and diversity of the malaria vector. Both activities were held four weeks in dry season and four weeks in rainy season. The mea-surement of physical factors such as temperature, humidity and rainfall were also conducted to support the study results. Four dusuns which meet the criteria and had the highest malaria cases were selected as study location. Descriptively, the results shows that the number of collected Anopheles in cocoa farming were higher compared with those in mix horticultural farming; and the number of Anopheles species identifi ed in cocoa farming were also more varied than those in the mix horticultural farming.Key words: bionomik vektor malaria, anopheles,

Bewirtschaftung von tropischen Sekundärwäldern

2002 ◽  
Vol 46 (1) ◽  
Author(s):  
Dietrich Schmidt-Vogt
Keyword(s):  
Land Use ◽  
Forest Cover ◽  
Stand Structure ◽  
Secondary Forest ◽  
Secondary Forests ◽  
Tropical Asia ◽  
Land Use Systems ◽  
The Future ◽  
The Tropics ◽  
Primary Forests

AbstractManagement of secondary tropical forests: a new perspective for sustainable use of forests in Asia. The decline of primary forests in the tropics is leading to a reassessment of the role secondary forests might play within the context of tropical forest management. Recent research has shown that secondary forests in the tropics can be both rich in species and complex in terms of stand structure. There is, moreover, a growing recognition of the importance of secondary forests for traditional subsistence economies in the tropics and of their economic potential for land use systems in the future. Management of secondary forests in Asia as an alternative to the extraction of timber from primary forests but also as one among other options to intensify traditional land use systems has a potential for the future especially because of the existence of vast tracts of valuable secondary forest cover, and because of the store of traditional knowledge that can still be found in tropical Asia.

Financial compensation and uncertainty: using mean-variance rule and stochastic dominance to derive conservation payments for secondary forests

2008 ◽  
Vol 38 (12) ◽  
pp. 3033-3046 ◽  
Author(s):  
Thomas Knoke ◽  
Patrick Hildebrandt ◽  
Daniel Klein ◽  
Rodrigo Mujica ◽  
Martin Moog ◽  
...  
Keyword(s):  
Land Use ◽  
Decision Maker ◽  
Secondary Forest ◽  
Distribution Functions ◽  
Cumulative Distribution ◽  
Opportunity Costs ◽  
Secondary Forests ◽  
Financial Compensation ◽  
Systematic Risks ◽  
Mean Variance

The expected opportunity costs of conserving a specific land use are usually considered adequate as financial compensation. However, a “conservation premium” is sometimes proposed as an added incentive, i.e., compensation greater than the expected opportunity costs. This paper discusses various methodological opportunities for deriving effective compensation under uncertainty. Based on cumulative distribution functions of possible opportunity costs (a Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) plantation was considered the alternative to conserving a Chilean secondary forest), generated through Monte Carlo simulations, we derived an inclusive range of possible compensations from 77 up to 375 US$·ha–1·year–1. If we assumed that the two land-use alternatives were mutually exclusive and independent from other risky investments, a compensation of 375 US$·ha–1·year–1 was necessary to convince every decision maker to maintain the secondary forest. However, only 77 US$·ha–1·year–1 was enough for a risk-averse decision maker (given average opportunity costs of 113 US$·ha–1·year–1). Yet, it turned out that the greatest possible opportunity costs would already be compensated for with 199 US$·ha–1·year–1, given an error probability of 0.05. Compensating for the last 5% of possible opportunity costs would thus require an additional 176 US$·ha–1·year–1. Our approach had two main limitations, namely we did not consider portfolio effects, which would allow diversifying away unsystematic risks, and we did not take into account the different systematic risks of the compared alternatives. These limitations may have led to an overestimation of effective compensation.

Land use change in Amazonian Dark Earth and Acrisol: Responses of organic carbon, organic matter composition and microbial carbon utilisation

2020 ◽  
Author(s):  
Klaus Jarosch ◽  
Luis Carlos Colocho Hurtarte ◽  
Konstantin Gavazov ◽  
Aleksander Westphal Muniz ◽  
Christoph Müller ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Community Structure ◽  
Microbial Community ◽  
Organic Carbon ◽  
Land Use Change ◽  
Microbial Community Structure ◽  
Secondary Forest ◽  
Soil Types ◽  
Amazonian Dark Earth

&lt;p&gt;The conversion of tropical forest for cassava cultivation is widely known to decrease the soil organic matter (OM) and nutrient contents of highly weathered soils in the tropics. Amazonian Dark Earth (ADE) might be affected less due to their historical anthropogenic amelioration with e.g. charcoal, ceramics and bones, leading to higher soil OM and nutrient concentrations. In this study, we analysed the effect of land use change on the OM dynamics and its composition under tropical conditions, using ADE and an adjacent Acrisol (ACR) as model systems. Soil samples were obtained south of Manaus (Brazil), from a secondary forest and an adjacently located 40-year-old cassava plantation. The land use change induced a severe decrease of organic carbon (OC) concentrations in ADE (from 35 to 15&amp;#160;g&amp;#160;OC&amp;#160;kg&lt;sup&gt;&amp;#8209;1&lt;/sup&gt;) while OC in the adjacent ACR was less affected (18 to 16&amp;#160;g&amp;#160;OC&amp;#160;kg&lt;sup&gt;&amp;#8209;1&lt;/sup&gt;). Soils were analysed by &lt;sup&gt;13&lt;/sup&gt;C NMR spectroscopy to obtain information on how the conversion of secondary forest to cassava affected the chemical composition of OM. Our results show that land use change induces differences in the OM composition: The OM in ADE changes to a more decomposed state (increase of alkyl:O/N-alkyl ratio) whereas the OM in ACR changes to a less decomposed state (decrease of alkyl:O/N-alkyl ratio). According to a molecular mixing model, land use change influenced mostly the proportion of lipids, which might be related with a change of the plant input. The incubation of the soils with &lt;sup&gt;13&lt;/sup&gt;C glucose enabled resolving how soil microorganisms were affected by land use change. In both soil types ADE and ACR, land use change caused a reduction of the total &lt;sup&gt;13&lt;/sup&gt;C glucose respiration by approximately one third in a 7-days incubation, implying lower microbial activity. Microorganisms in both soil types appear to be more readily active in soils under forest, since we observed a distinct lag time between &lt;sup&gt;13&lt;/sup&gt;C glucose addition and respiration under cassava planation. This indicated differences in microbial community structure, which we will assess further by determining the &lt;sup&gt;13&lt;/sup&gt;C label uptake by the microbial biomass and the microbial community structure using &lt;sup&gt;13&lt;/sup&gt;C PLFA analysis. Preliminary results from synchrotron-based STXM demonstrate a distinct arrangement of OM at fine-sized charcoal-particle interfaces. Samples of soils receiving &lt;sup&gt;13&lt;/sup&gt;C label will be further analysed by NanoSIMS with the hypothesis that charcoal interfaces foster nutrient dynamics at the microscale. Despite the high loss of OC in the ameliorated ADE through land use change, the remaining OM might improve the nutrient availability thanks to charcoal interactions compared to the ACR. Our results contribute to a better understanding of the sensitivity of OM upon land use change and how the microbial community is responding to land use change in highly weathered tropical soils.&lt;/p&gt;

scholarly journals Vertical In-Vessel Composter for Stabilization of Market Vegetable Waste

2020 ◽  
Vol 9 (3) ◽  
pp. 486-490
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Organic Waste ◽  
Research Work ◽  
Chemical Characteristics ◽  
Vegetable Waste ◽  
Initial Concentration ◽  
Mix Proportion ◽  
Physico Chemical ◽  
Seeding Material

Composting can be one of the solutions to tackle the issue of handling solid waste. In the present research work, a bench-scale vertical in-vessel aerobic composter was designed to stabilize the Devaraja market vegetable waste, Mysore using horse dung and plantain leaves as seeding material and bulking agent respectively. On average, Devaraja market generate 4.8-5.6 ton per day. Mix proportion of organic waste, bulking and seeding materials fed into composter was in the ratio of 5: 1: 0.5. Initial and variation in physico-chemical characteristics of waste were monitored during the composting period. The initial concentration of total nitrogen, phosphorous, total organic carbon and C/N ratio which was found to be 1.67%, 0.78%, 1.93%, 43.5% and 26 showed a variation of 2.4%, 1.1%, 2% 29% and 15 respectively at the end of 21 days of composting.

scholarly journals Microbial Community, Biomass and Physico-Chemical Properties of Soil in dry tropics

2020 ◽  
Author(s):  
Weldesemayat Gorems Woldemariam ◽  
Nandita Ghoshal
Keyword(s):  
Land Use ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Agricultural Land ◽  
Natural Forest ◽  
Degraded Forest ◽  
Microbial Properties ◽  
Physico Chemical ◽  
Land Use Types ◽  
Bamboo Plantation

Abstract Soil physicochemical and microbial properties can be regarded as an important tool to assess soil quality and health. Studying the soil properties under different land use types is great practical significant for land use and soil management regarding soil carbon dynamics and climate change mitigation. However, the changes in land-use types and their effects on soil physicochemical and microbial properties are largely debated and rather unclear. Four different land use types were used to study soil microbial and soil physico-chemical properties. Soil organic carbon and total nitrogen, soil microbial biomass and microbial diversity were determined by micro kjeldahl method, fumigation and extraction method and FAME GC-Ms, respectively. Among all land use pattern the highest water holding capacity (40.06±0.74%), porosity (0.539±0.011%), soil macro-aggregates (64.16±2.64%), organic carbon (0.84±0.054%), total nitrogen (0.123±0.013%), microbial biomass carbon (570.65±35.05 μg/g) and nitrogen (84.21±3.186 μg/g), basal respiration (3.64±0.064μg/g) and b-glucosidase (809.68±39.7μgμg PNP g-1 dry soil h-1) were found to be under natural forest followed by in decreasing order bamboo plantation, degraded forest and agricultural land. Significant differences were observed among the land use types with microbial biomass carbon and B-glucosidase activity. Furthermore, the correlation of analysis showed that microbial biomass, organic carbon, b-glucosidas activity, total nitrogen, moisture content, porosity, water holding capacity, soil macro aggregates were positively correlated to each other and negatively correlated with bulk density, meso and micro soil aggregates at p<0.05. The PLFA analysis showed that microbial community diversity exhibited distinct patterns among land-use types. The conversions of natural forest to other land use type, the amount of PLFA were reduced significantly. The natural forest had high microbial diversity followed by in decreasing order bamboo plantation, degraded forest and agricultural land. Among the organisms G- bacteria and fungi were showed decreasing order from natural forest, bamboo plantation, degraded forest and agricultural land. The reverse was true for G+ bacteria. The result of this study showed that soil physico-chemical and microbial properties were significantly affected by land use types. Thus bamboo based fallow has the potential for improving soil quality and properties in the short term.

scholarly journals Productivity and nutritional value of elephant grass BRS Canará forage

2019 ◽  
Vol 40 (6) ◽  
pp. 2705
Author(s):  
Eduardo André Ferreira ◽  
Joadil Gonçalves de Abreu ◽  
Junio Cesar Martinez ◽  
Ricardo Santos Silva Amorim ◽  
Arthur Behling Neto ◽  
...  
Keyword(s):  
Rainy Season ◽  
Linear Response ◽  
Leaf Blade ◽  
Dry Season ◽  
The Other ◽  
Chemical Characteristics ◽  
Elephant Grass ◽  
Insoluble Protein ◽  
Forage Production ◽  
Quadratic Response

The goal was to determine the ideal cutting age of elephant grass BRS Canará for forage production in the dry and rainy seasons. The experimental design comprised randomized blocks, with five treatments (42, 56, 70, 84, and 98 days in the dry season and 42, 60, 76, 91, and 105 days of regrowth in the rainy season) and four replications each. Agronomic, morphological, and chemical characteristics were evaluated. In the dry season, there was a significant quadratic response for plant height and leaf blade length. For the other characteristics, a significant linear response was observed, except stem diameter. In the rainy season, a quadratic response for the leaf blade length, leaf blade width, and leaf:stem ratio was observed. For the other characteristics, there was a significant linear effect, except for the percentage of dead material. In the dry season, a verified linear response was observed for the chemical characteristics, except neutral detergent insoluble protein. In the rainy season, a linear response was verified for all evaluated characteristics, except acid detergent insoluble protein. Elephant grass BRS Canará for forage production should be cut between 70 and 85 days in the dry season and between 60 and 70 days of regrowth in the rainy season.

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