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Peatlands play a crucial role in mediating the emissions of methane through active biogeochemical cycling of accumulated carbon driven by methane-metabolizing microorganisms; meanwhile, they serve as vital archives of atmospheric heavy metal deposition. Despite many edaphic factors confirmed as determinants to modulate the structure of methanotrophic and methanogenic communities, recognition of interactions among them is limited. In this study, peat soils were collected from Dajiuhu peatland to assess the presence of heavy metals, and methanotrophs and methanogens were investigated via high-throughput sequencing for functional genes mcrA and pmoA. Further analyses of the correlations between methane-related functional groups were conducted. The results demonstrated that both methane-metabolizing microorganisms and heavy metals have prominent vertical heterogeneity upward and downward along the depth of 20 cm. Pb, Cd, and Hg strongly correlated with methanotrophs and methanogens across all seasons and depths, serving as forceful factors in structural variations of methanogenic and methanotrophic communities. Particularly, Pb, Cd, and Hg were identified as excessive elements in Dajiuhu peatland. Furthermore, seasonal variations of networks among methane-related functional groups and environmental factors significantly affected the changes of methane fluxes across different seasons. Concretely, the complicated interactions were detrimental to methane emissions in the Dajiuhu peatland, leading to the minimum methane emissions in winter. Our study identified the key heavy metals affecting the composition of methane-metabolizing microorganisms and linkages between seasonal variations of methane emissions and interaction among heavy metals and methane-metabolizing microorganisms, which provided much new reference and theoretical basis for integrated management of natural peatlands.

Wetland ecosystems are the most important natural sources of methane (CH4), with periodical changes of CH4 fluxes observed. Methanogens and methanotrophs are considered as the key factors affecting CH4 fluxes in wetlands. However, the relationship between methanogens and methanotrophs was still unclear. To close this gap, samples at four depths of soil in the Dajiuhu subalpine peatland in January, April, July, and October 2019 were collected and CH4 fluxes data from the eddy covariance (EC) system was acquired. The phylogenetic molecular ecological networks (pMENs) analysis was used to identify keystone species and the seasonal variations of co-occurrence patterns of methanogenic and methanotrophic communities. The results indicated that the seasonal variations of interactions between methanogenic and methanotrophic communities contributed to CH4 emissions in wetland. The keystone species discerned by network analysis also showed their importance in mediating CH4 fluxes. CH4 emissions in wetland were lowest in spring, during this period, most complex interactions between microbes were observed, with the intense competition among methanogens while methanotrophs represented better cooperation. Reverse patterns manifested in summer, when the highest CH4 flux was observed. Meanwhile, Methanoregula formicica was proven negatively correlated with CH4 fluxes that occupied largest ecological niches in the spring network, and Methanocella arvoryzae, as well as Methylocystaceae had positive correlations with CH4 fluxes survived better in the microbial community in summer. In addition, soil temperature and nitrogen were regarded as significant environmental factors to CH4 fluxes. This study explained the seasonal patterns and microbial driving mechanisms of CH4 emissions in wetlands.

The rapid development of modern society has resulted in discharge of large, heavy metal quantities into wetlands that have been continuously accumulating, causing severe pollution. Dajiuhu, located in the Shennongjia Forest District of Hubei Province in China, is a wetland of significant value internationally, serving as a model wetland ecosystem with heightened scientific research value. In this study, 27 surface sediment samples from nine sub-lakes in Dajiuhu were collected in August 2020. The concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the sediments were determined. The heavy metal occurrence and speciation characteristics were analyzed by an improved BCR (European Community Bureau of Reference) extraction method. Four methods were used to evaluate heavy metals' pollution degree and ecological risk. The possible source of heavy metals was inferred using correlation analysis and principal component analysis. The heavy metal content in the lake sediments of Dajiuhu wetland was from the highest to the lowest concentration as follows: Zn [Formula: see text] Cr [Formula: see text] Ni [Formula: see text] Pb [Formula: see text] Cu [Formula: see text] Cd. The average Cd content exceeded the national nature reserve threshold values, while the other heavy metals measured were below their respective threshold values. However, due to the occurrence of Pb and Cd in different forms, they still pose certain pollution and ecological risk to the lake wetlands. On the other hand, Zn, Cr, Ni, and Cu do not pose an ecological risk in the lakes of the Dajiuhu wetland. The spatial distribution of heavy metal content in the nine sub-lakes did vary significantly. Regarding the heavy metal sources in the lake sediments, Ni, Cr, and Cu originate from natural factors, and Cd and Pb have mainly anthropogenic origins. In contrast, Zn has both natural and anthropogenic origins. This study provides further insights into the study of heavy metal pollution in lake wetlands. It provides a framework and a direction for managing heavy metal pollution in the Dajiuhu wetland.

Problem definition: Nanostores are traditional, small and independent retailers that are present in large numbers in the megacities of the developing world. Consumer packaged goods (CPG) manufacturers can choose to deliver to nanostores either directly—visiting thousands of stores per day—or via wholesalers—saving on distribution cost but forfeiting the direct access to the store owners to develop demand. We study a manufacturer’s channel strategy within a finite time horizon. Academic/practical relevance: The channel strategy in emerging markets has both marketing and operational elements, which lead to a newly formulated problem with novel characteristics. High costs are involved in the nanostore distribution, and the difference in wholesale price, logistics cost, product availability, and market growth leads to a multidimensional problem that is not trivial to analyze. Methodology: We develop an analytical model to derive the optimal channel policy. We conduct a numerical study with parameters tuned by field data. We develop managerial insights based on our formal results and our numerical analysis. Results: The optimal channel policy structure depends mainly on two channel metrics: the gross profitability, which is the gross margin at a particular moment in time; and the growth-adjusted profitability, which includes the growth potential of a particular channel strategy to develop the market and realize future profits. With demand growth over time, we show that, in the optimal policy, there is at most one switch between the wholesale and direct-channel strategies within the time horizon. Managerial implications: Depending on the two metrics, it may be optimal to first expand the market by using the direct channel and then switch to the wholesale channel to exploit the expanded market. In other cases, it may be optimal to first expand the market slowly by using the wholesale channel and then switch to the direct channel to benefit from high demand growth. The optimal channel strategy is also dependent on the time horizon, with a longer time horizon leading to relatively longer use of the direct channel.

Peatland ecosystems play an important role in the global carbon cycle because they act as a pool or sink for the carbon cycle. However, the relationship between seasonality effect factors and net ecosystem CO2 exchange (NEE) remains to be clarified, particularly for the non-growing season. Here, based on the eddy covariance technique, NEE in the peatland ecosystem of Central China was examined to measure two years’ (2016 and 2017) accumulation of carbon dioxide emissions with contrasting seasonal distribution of environmental factors. Our results demonstrate the cumulative net ecosystem CO2 emissions during the study period was in the first non-growing season 2.94 ± 4.83 μmolCO2 m-2.s-1 with the lowest values in the same year in first growing season was -2.79 ± 4.92 μmolCO2 m-2.s-1. The results indicate the effect of seasonal variations of NEE can be directly reflected in daily and seasonal variations in growth and respiration of peatland ecosystem by environmental parameters over different growing stages.

Methane (CH4) flux was measured by using the Eddy covariance technique in the Dajiuhu Wetland of Shennongjia Forestry District, Hubei Province, China. The seasonal and daily variation of CH4 emissions was investigated, and the correlation of CH4 fluxes with the environmental impact factors were discussed to understand the activity of CH4 flux and the effects of environmental factors including air temperature, soil temperature, photosynthetic photon flux density (PPFD), and rainfall on a wetland ecosystem. The results indicated that CH4 flux was significantly correlated with air temperature and photosynthetic photon flux density (PPFD), which may be the primary driver of controlling peatland CH4 flux.

Non-small cell lung cancer (NSCLC) is still an unresolved source of tumor-related death internationally. Current studies have discovered that microRNAs (miRNAs) are associated with diverse cancers development, including NSCLC. Our paper focused on the functional character of miR-4286 in NSCLC. miR-4286 level in 68 cases of NSCLC tissues, matched neighboring nontumor tissues and different cancer cell lines were inspected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The connection concerning miR-4286 expression and clinicopathological features of patients with NSCLC were further determined. After knockdown or overexpression of miR-4286, cell viability, cell cycle, and/or apoptotic cells were examined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assay, respectively. Moreover, the cell cycle- and apoptosis-related proteins were estimated by qRT-PCR and Western blot. In comparison with the matched nontumor tissues, miR-4286 was significantly enhanced in lung malignancy tissues and different cell lines. miR-4286 expression was related with the tumor-node-metastasis stage, lymphatic metastasis, and distant metastasis. Cell viability was ominously weakened by suppression of miR-4286 in A549 cells, whereas was statistically upregulated by overexpression of miR-4286 in NCI-H1299 cells. Additionally, we detected that suppression of miR-4286 tempted cell cycle arrest in G1 stage and fortified apoptosis in A549 cells. Runx3 was recognized as one target gene of miR-4286, and the impacts of suppression of miR-4286 on cell viability and apoptosis were through regulation of Runt-related transcription factor 3. Our study suggests that miR-4286 overexpression represents a tumor promoter role in NSCLC cells.

Concurrent Transaction Logic (CTTZ) is a deductive language for programming database transaction applications that integrates queries, updates, and transaction composition in a complete logical framework. The language supports all the properties of classical trans­actions and the properties found in some new transaction models, e.g., sub-transactions, transaction rollback, and concurrent transactions. The contributions of this thesis are twofold. First, it extends CTTZ to account for timing-event-based prioritized concurrent systems in which transactions may have pri­ority and timing constraints. This extension of CTTZ, here called TV-CTTZ, provides a high-level logic programming framework for specifying and simulating executions of timed transactions and trigger-events commonly present in real-time concurrent appli­cations. Second, it describes a Prolog implementation of TV-CTTZ. The implemented TV-CTTZ prototype supports the translation from TV-CTTZ to CTTZ. Underlying this protocol, we use a simplified Rate-Monotonic algorithm [10] to schedule the execution of constraint concurrent transactions and built-in timing predicates to handle transaction time-relations.

Sinojackia huangmeiensis is a critically endangered tree species in the Styracaceae endemic to China. To create tools to better evaluate the genetic diversity of this species, we used a modified genomic library enrichment method, the PETUER (Probe Extension and TEACl Universal EnRichment) method, to develop genetic markers. The resulting 18 microsatellite loci had high polymorphism with 3–12 alleles per locus and showed negligible stutter. Observed (HO) heterozygosities were 0.057–0.724, and polymorphism information content (PIC) was 0.109–0.794. No significant linkage disequilibrium between pairs of loci was found. All 123 individuals found in the National Natural Reserve of Longgan Lake was genotyped at the 18 loci and used to estimate a UPGMA dendrogram. Using an iterative clustering method, a set of 18 individuals was established as a core collection to represent genetic diversity and would be useful to facilitate the conservation for S. huangmeiensis. In addition, we tested the 18 loci for cross-species amplification in three other Sinojackia species and the closely related Changiostyrax dolichocarpa. These polymorphic loci will be valuable for future population genetic and phylogenetic studies of S. huangmeiensis and congeneric species, as well as in closely related Styracaceae.

In Madagascar, the South and Southwest regions have for decades had locust outbreaks that have devastated crop fields. The locust species dominant in this area are the red locust (Nomadacris septemfasciata) and the Migratory Locust (Locusta migratoria capito). This paper aimed at determining the predation values from the Black Kite (Milvus migrans parasitus), a natural enemy for locusts, as a biological measure for locust outbreak control. Two types of experiments were done that included observed predation and experimental predation. It was observed, in the observed predation, that a higher number of locusts were found in the bird’s stomach during the afternoon session (mean = 66) than during the morning session (mean = 21). The high peak observed during the afternoon session was also associated with the feeding of larvae of the migratory locust. The experimental predation results showed that almost 100 percent of the larval and 97 percent of the fledglings were fed on. The experimental predation results also showed that there was no preference for larvae or fledglings in the cage and that the bird fed on the different combinations equally. This study showed that the Black Kite birds can effectively control locust population in an outbreak when they are easy to predate on. However, there is a need to assess the population of birds in locust infested areas to determine if the bird population is enough to predate on a locust outbreak.

Peatland ecosystem processes are strongly influenced by hydrology linked to climate change. However, how transpiration, as major water loss pathway in closed peatland, responds to climate change and then regulates ecosystem water balance that remains poorly understood. Here, we reported an 18,000-year fossil phytolith record from an herbaceous community-dominated mountain peatland in central China to reconstruct climate changes and vegetation evolution and reveal the interactions between regional climate changes and peatland ecosystem. The abundance of bulliform phytoliths—a silicified type of cells that regulate the movements of plant leaves to reduce light exposure and transpiration rate—shows close correlations with the Holocene climate variations with higher bulliform abundance in response to warm-dry climate (11,500–9600 cal yr BP; 7500–3000 cal yr BP) and lower values associated with cold-wet climate (13,000–11,500 cal yr BP; 3000 cal yr BP-present). Spectral analysis reveals that bulliform abundance and reconstructed climate vary with a major ~1000-year periodicity during the Holocene, suggesting a possible causal relationship to solar activity. A high bulliform abundance and warm-dry climate correspond with enhanced solar activity, and vice versa. We interpret that the resultant leaf water deficit resulted from greater light interception, high temperature and drought promoted the production of bulliform cells to fold leaf for water conservation, which is an effective protective mechanism of peatland grasses from the environmental stress. These results expand our understanding of how grass-dominated peatland plant water regulation recorded by bulliform phytoliths responds to solar radiation and local hydroclimate during geological period.

The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental variables. Understanding this response requires examining factors or their interactions that have influence on plant and resource availability. Our objective was to analyze the relationships between changes in plant abundance and the interaction among environmental habitat factors including soil, geological (rock type), and other environmental variables in the Longhushan karst mountains ecosystem. Species density and dominance were examined using ANOVA, ANCOVA, and Generalized Linear Models to establish the single or combined effects of these groups of factors. The results showed that trends in abundance were mainly affected by rock type (related to the percentage content of dolomite and calcite), soil characteristics in association with topography. Bothplant indices were higher in dolomite dominated areas and varied positively with moisture, and elevation, but negatively with organic matter, while density also increased with slope degree. The results demonstrate that significant variations in species abundance was produced with the combination of variables from soil, geological, and environmental factors, suggesting their interaction influence on plants. We postulate that spatial variations in plant abundance in karst ecosystem depends on the carbonate rock type in addition to water and nutrient availability which are mainly controlled by topography and other factors such as soil texture and temperature. The study suggests that in karst areas carbonate rock type, in addition to local environmental variables, should be taken into account when analyzing the factors that have impact on plant communities.

This research describes modern phytolith records and distributions from subalpine surface soils in the Dalaoling Forest Reserve, and reveals its implications for local climate conditions with respect to the altitude gradient. Well-preserved phytolith morpho-types, assemblages, and climatic indices were used to study the relationship between local vegetation and climate conditions. The phytolith classification system is mainly based on the characteristics of detailed morpho-types described for anatomical terms, which are divided into seven groups: long cells, short cells, bulliform cells, hair cells, pteridophyte type, broad-leaved type, and gymnosperm type. Phytoliths originating from the Poaceae are composed of Pooideae (rondel and trapeziform), Panicoideae (bilobate, cross, and polylobate), Chloridoideae (short/square saddle), and Bambusoideae (oblong concave saddle). Based on the altitudinal distribution of the phytolith assemblages and the indices of aridity (Iph), climate (Ic), and tree cover density (D/P), five phytolith assemblage zones have revealed the five types of climatic conditions ranging from 1,169 m to 2,005 m in turn: warm-wet, warm-xeric to warm-mesic, warm-xeric to cool-mesic, cool-xeric, and cool-mesic to cool-xeric. The Bambusoideae, Panicoideae, and Chloridoideae are the dominant vegetation at the lower-middle of the mountains, while Pooideae is mainly distributed in the higher mountains. The close relationship between phytolith assembleages and changes of altitude gradient suggest that vegetation distribution patterns and plant ecology in the Dalaoling mountains are controlled by temperature and humidity conditions. Our results highlight the importance of phytolith records as reliable ecoclimatic indicators for vegetation ecology in subtropical regions.

Sinojackia is a Chinese endemic genus of Styracaceae, containing eight species. The taxonomy of one species, Sinojackia dolichocarpa (≡ Changiostyrax dolichocarpa ), is controversial. Here we investigate the distribution of leaf wax n -alkanes to clarify the chemotaxonomic position of S. dolichocarpa . Leaf samples of six Sinojackia species from Wuhan Botanical Garden in central China were collected during April, July, and December in 2010 to capture different developmental stages of the epicuticular waxes. Our results show that the waxes of S. dolichocarpa differ from the other five species by having a lower abundance of n C 31 but a higher abundance of n C 33 . Although developmental variations of n -alkane distributions were observed during the sampling periods, cluster analysis based on the percentages of n -alkanes from C 27 to C 33 separates S. dolichocarpa from the other Sinojackia species. Based on these finding, we suggest S. dolichocarpa is a species independent of the Sinojackia genus.

To provide the reasonable basis for scientific management of water resources and certain directive significance for sustaining health of Gufu River and even maintaining the stability of water ecosystem of the Three- Gorge Reservoir of Yangtze River, central China, multiple statistical methods including Cluster Analysis (CA), Discriminant Analysis (DA) and Principal Component Analysis (PCA) were performed to assess the spatial- temporal variations and interpret water quality data. The data were obtained during one year (2010~2011) of monitoring of 13 parameters at 21 different sites (3003 observations), Hierarchical CA classified 11 months into 2 periods (the first and second periods) and 21 sampling sites into 2 clusters, namely, respectively upper reaches with little anthropogenic interference (UR) and lower reaches running through the farming areas and towns that are subjected to some human interference (LR) of the sites, based on similarities in the water quality characteristics. Eight significant parameters (total phosphorus, total nitrogen, temperature, nitrate nitrogen, total organic carbon, total hardness, total alkalinity and silicon dioxide) were identified by DA, affording 100% correct assignations for temporal variation analysis, and five significant parameters (total phosphorus, total nitrogen, ammonia nitrogen, electrical conductivity and total organic carbon) were confirmed with 88% correct assignations for spatial variation analysis. PCA (varimax functionality) was applied to identify potential pollution sources based on the two clustered regions. Four Principal Components (PCs) with 91.19 and 80.57% total variances were obtained for the Upper Reaches (UR) and Lower Reaches (LR) regions, respectively. For the UR region, the rainfall runoff, soil erosion, scouring weathering of crustal materials and forest areas are the main sources of pollution. The pollution sources for the LR region are anthropogenic sources (domestic and agricultural runoff, hydropower exploitation and municipal waste). The study demonstrates the utility of multivariate statistical techniques for river water quality assessment, identification of pollution sources, and exploring spatial and temporal variations of water quality.

The primary purpose of this study was to assess water losses by evapotranspiration, evaporation and seepage in arid zone. Normally, evaporation and seepage are the main causes of water losses. For modeling water losses, a combination of Genetic Programming (GP), Penman-Monteith (PM) and Penman combination model for measurement of evapotranspiration, evaporation and seepage has been developed. The results were found to be varying depending on how the evaporation and seepage phenomena are modeled. These results show that that there is an improvement in reducing evapotranspiration, evaporation and seepage losses in arid and semi-arid region.

This study has focused on the processes of soil degradation and chemical element concentration in tea-growing regions of Rwanda, Africa. Soil degradation accelerated by erosion is caused not only by topography but also by human activities. This soil degradation involves both the physical loss and reduction in the amount of topsoil associated with nutrient decline. Soil samples were collected from eleven tropical zones in Rwanda and from variable depth within each collecting site. Of these, Samples from three locations in each zone were analyzed in the laboratory, with the result that the pH of all soil samples is shown to be less than 5 (pH

Biomass energy is drawing more and more attention from the community because of its renewable characteristics. The article has analyzed the position of biomass energy development and utilization in China. At the same time, the article has studied the main problems inherent in biomass energy development and utilization in China and introduced special proposals and policies.

The main purpose of this study conducted from August 2010 was to find biomass and productivity of epilithic algae and their relations to environmental factors and try to explore the restrictive factors affecting the growth of algae in the Gufu River, the one of the branches of Xiangxi River located in the Three Gorges Reservoir of the Yangtze River, Hubei Province, Central China. An improved method of in situ primary productivity measurement was utilized to estimate the primary production of the epilithic algae. It was shown that in rivers, lakes, and reservoirs, algae are the main primary producers and have a central role in the ecosystem. Chlorophyll a concentration and ash-free dry mass (AFDM) were estimated for epilithic algae of the Gufu River basin in Three Gorges Reservoir area. Environmental factors in the Gufu River ecosystem highlighted differences in periphyton chlorophyll a ranging from 1.49 mg m−2 (origin) to 69.58 mg m−2 (terminal point). The minimum and maximum gross primary productivity of epilithic algae were 96.12 and 1439.89 mg C m−2 day−1, respectively. The mean net primary productivity was 290.24 mg C m−2 day−1. The mean autotrophic index (AFDM:chlorophyll a) was 407.40. The net primary productivity, community respiration ratio (P/R ratio) ranged from 0.98 to 9.25 with a mean of 2.76, showed that autotrophic productivity was dominant in the river. Relationship between physicochemical characteristics and biomass was discussed through cluster and stepwise regression analysis which indicated that altitude, total nitrogen (TN), NO3−-N, and NH4+-N were significant environmental factors affecting the biomass of epilithic algae. However, a negative logarithmic relationship between altitude and the chlorophyll a of epilithic algae was high. The results also highlighted the importance of epilithic algae in maintaining the Gufu River basin ecosystems health.

This paper presents the results of the study undertaken at Lubumbashi City in D.R.Congo to determine the spatial distribution and evolution of Pentecost churches in Africa urban environment. It was shown that in Lubumbashi City the Pentecost Churches were grown from 112 churches in 1990 to 280 Churches in 2008. Four Church Community groups were identified which are 8th CEPAC (19 churches), 30th CEPECO (102 churches), 45th CEP (39 churches) and RESURGENCE CHURHCES (120 churches). The last cited knew a high proliferation and grew from 24 Churches to 120 Churches in the same period. The analysis of their spatial distribution by using the Distribution Model showed that the concentration of spatial distribution is R=0.416. The study of correlation between the number of Churches, the number of population and the area by using the formula of correlation coefficient shows that no correlation exists for their distribution. The need of money, accessibility and good environment were a basis of their proliferation. Finally we addressed the advices and proposed an appropriate method to all actors in order to establish a harmony in urban environment.

This study was undertaken to assess the erosion control verification. The intensity analysis using method of hole by capturing of water flow on mountainsides was a good indication for verification. It showed that the speed of this water was reduced from 1 hour in April 2007 to 7 hours 12 minutes in April 2008 in Rwanda where radical terraces were the main method for erosion control. In Xinjiang, the intensity of erosion varied between 7 hours 23 minutes and 10 hours 7 minutes from January to December 2009. Finally we proposed this strategy for all different parts of the whole world where erosion is still a big challenge to assess its intensity in order to preserve its consequences in the environment.

The aim of this study was to access the pH and soil degradation. Soil samples collected in eleven zones among three locations by zone were analyzed in the laboratory through pH Meter and the results indicates that pH of all soil samples is less than 5 (pH

This study uses remote sensing and spatial modeling to quantify and analyze land-cover change in one of Cameroon's rich ornithological montane forest biomes, the Kilum/Ijim mountain forest and surrounding watersheds. Change trajectories are identified over the entire watershed for a thirty year period (1978–2008). The role of satellite imagery, biophysical variables, locational context, and household socioeconomics factors in driving land-cover change were assessed. Overall, the documented land cover changes increase provisioning services such as crops and cattle that are characteristic some of the cultural landscapes in the area but may cause an irreversible loss of biodiversity and a depletion of other ecological services provided by forests and shrublands. The explanatory variables of the spatial model suggests that land-cover change in the region is explained many variables including proximity to road and land suitability. The implications for conservation of this area and the need for territorial planning and adapted land-use strategies are discussed.

The analysis of water samples collected in rivers streams across the tea growing areas in Rwanda by using spectroscopy technique MS Instrument has clearly indicate the presence of heavy elements (Al, As, Ba, c, Ca, Cu, Fe, H+, K, Mg, Mn, N, P, S, Si, and Zn) in water samples. The highly concentrated are: Ca (37 - 54.9), C (31.5-36.4), S: 12.9-24.1, Mg: 8.5-14.1, N: 4-11 and K: 5.3-7.8. Those with medium concentration are Si: 3.4-5.4, Cu: 1.1-2.5, Mn: 0.7-1.5, Ba: 0.5-1.03, Fe: 0.6-1 and P: 0.6-0.8. And elements with low concentration are Zn: 0.3-0.76, H+: 0.4-0.66, Al: 0.4-0.6 and As: 0.02-0.5. The pH varies between 5.5- 6.7.Water is acidic and this acidity may be caused by the use of fertilizers and pesticides with high quantity of NPK + Mg. Here we proposed the method that can be applied in order to maintain the quality of drinking water.

In this paper, non timber forest products presence and abundance in the Central zone of Korup National Park (CKNP), South Western Cameroon, are assessed and mapped based on habitats that support them. Sampling was done to identify all potential product plant species in the study area, derive estimates of abundance and describe productive habitats. The results show that, for most of the species, occurrence is not uniformly distributed. The estimated probability of identifying a species rose from 23% to 44% over the range of abundances in the plot. Species with a relatively high abundance were medicinal plants especially Anchomanes difformes.Valuable commercial species such as Irvingia gabonensis and Dacryodes edulis were rare. Some soil variables (Sand, Organic carbon, Clay, etc.) influence their spatial distribution. While there is some clustering, the pattern may be due to random chance (General G Index = 0, Z score =-1.44 standard deviations). Sustainable management of these products is important, both for local livelihoods, and preserving many that are facing rapid depletion.

Twenty modified-Whittaker plots were stratified at different sampling locations from February to May of 2008 in the central zone of Korup National Park, Cameroon. Our interest was to assess floristic diversity and investigate their relationship with environmental variables. Diversity profiles and rank abundance–curves were used for diversity analysis while canonical correspondence analysis and species–response curves were used to investigate the relationships between the response and explanatory variables. Of the 66 families identified, the Rubiaceae (999 species) were the most abundant. The Sterculiaceae (basal area = 10.482 m2 ha−1) were the dominant family, while the co-dominant families included the Ebenaceae (basal area = 9.092 m2 ha−1) and the Euphorbiaceae (basal area = 8.168 m2 ha−1). Soil variables explained 54.3% of total variation in family distribution. Canonical axes were related to different environmental gradients: axis1 was related to increasing canopy cover (r = 0.6951); axis 2, increasing Magnesium (r = 0.8465) and effective cation exchange capacity (r = 0.5899); axis 3, increasing effective cation exchange capacity (r = 0.5536); while axis 4, increasing Phosphorus concentration (r = 0.5232). Our results demonstrate the advantage which diversity profiles have over single or combination of indices, and the importance of using a combination of methodologies in diversity analysis. Resume De fevrier a mai 2008, vingt parcelles de Whittaker modifie ont ete stratifiees a differents sites d’echantillonnage dans la zone centrale du Parc National de Korup, au Cameroun. Nous voulions evaluer la diversite floristique et etudier son lien avec diverses variables environnementales. Nous avons employe des profils de diversite et des courbes de rangs d’abondance pour l’analyse de la diversite, tandis que nous utilisions une analyse canonique des correspondances et des courbes de reponse des especes pour etudier les relations entre les reponses et les variables explicatives. Sur les 66 familles identifiees, les Rubiacees (999 especes) etaient les plus abondantes. Les Sterculiacees (surface basale = 10,482 m2 ha−1) etaient la famille dominante et, parmi les familles co-dominantes, il y avait les Ebenacees (surface basale = 9,092 m2 ha−1) et les Euphorbiacees (surface basale = 8,168 m2 ha−1). Des variables du sol expliquaient 54,3% de la variation totale de la distribution des familles. Les axes canoniques ont ete lies aux differents gradients environnementaux; l’axe 1 etait liea une couverture croissante de la canopee (r = 0,6951); l’axe 2 a une augmentation du magnesium (r = 0,8465) et a la capacite reelle d’echange de cations (r = 0,5899); l’axe 3 a une capacite reelle croissante d’echanges de cations (r = 0,5536); et l’axe 4 a une concentration croissante en phosphore (r = 0,5532). Nos resultats montrent l’avantage que les profils de diversite ont sur des indices uniques ou combines et l’importance d’utiliser une combinaison de methodologies dans une analyse de diversite.