Cocoa plantation carbon stock at different years after planting (5,10,15) in Tomoni Beringin Jaya Village, East Luwu, South Sulawesi, Indonesia

This study aimed to determine cocoa carbon stocks based on the conditions of cocoa plantations in Tomoni Beringin Jaya Village, East Luwu, South Sulawesi, Indonesia. Carbon stocks were estimated from aboveground and belowground biomass using an allometric methodology. Sample sites were cocoa plantations; sampling intensity was 30% of the land planted with cocoa for 5 years (n = 214), 10 years (n=229) and 15 years (n=329), soil sampling disturb (measure soil organic carbon), un disturb (measure bulk soil bulk density) and soil bulk density at depth 0-10 cm and 10-20 cm. Carbon stock cocoa aboveground biomass at the age of 5 years (M45) was 1.89 ton C ha-1 and belowground biomass was 0.56 ton C ha-1 with proportion 77.19%:22.81%. Carbon stock cocoa aboveground biomass at the age of 10 year (BR25) was 3.66 ton C ha-1 and belowground biomass 1.01 ton C ha-1 with a proportion 78.37%:21.63%. Carbon stock cocoa aboveground biomass at 15 year (BR25) was 4.58 ton C ha-1 and belowground biomass of 1.21 ton C ha-1 with a proportion 79.07%:20.93%. Cocoa carbon stock at 5 year, 10 year, and 15 year respectively increased, nevertheless mean annual carbon stock cocoa decreased in 5 years cocoa aboveground biomass was 0.37 ton C ha-1 and belowground biomass 0.11 tonCa-1. Carbon stock cocoa 10 year aboveground biomass 0.36 ton C ha-1 and belowground biomass 0.10 ton C ha-1. Carbon stock cocoa 15 year aboveground biomass 0.30 ton C ha-1 and belowground biomass 0.08 ton C ha-1. Soil organic carbon showed dynamic under different year cocoa plantation. Soil organic carbon in cocoa plantation age 5 year was 0.031 tonCha-1, cocoa plantation age 10 year was 0.034 ton C ha-1, and cocoa plantation age 15 year was 0.043 ton C ha-1.

Eucalyptus Plantation Age and Species Govern Soil Fungal Community Structure and Function Under a Tropical Monsoon Climate in China

Fungi perform crucial roles in nutrient cycles, but there is limited information on how soil fungal communities vary with stand age and tree species. Eucalyptus has been extensively planted in China, which has caused severe soil erosion and water deficiency due to short rotation management. In this study, the fungal community structure and potential function in Eucalyptus plantations with different ages (1–5+ years) and species (Eucalyptus urophylla × Eucalyptus grandis, Eucalyptus camaldulens, and Eucalyptus pellita) under a tropical monsoon climate in China were characterized by Illumina Miseq coupled with FUNGuild analysis. The results showed that the fungal alpha diversity decreased with an increase in the age of the plantation. Plantations of different ages and species formed distinct fungal communities and potential functional structures, respectively (p < 0.05), in which the age of the plantation contributed more to the variations. At high taxonomic levels, the soil fungal community changed from the dominance of orders belonging to Ascomycota (Pleosporales, Chaetothyriales, and Eurotiales) to orders belonging to Basidiomycota (Agaricales, Sebacinales, Cantharellales, and Russulales) with increasing plantation age. The community potential function shifted from the dominance of plant pathogens to a higher abundance of saprotrophs and symbiotrophs. The organic carbon of the soil was the key environmental driver to both the fungal community and potential functional structure. The results provide useful information on the importance of fungi for the management of Eucalyptus plantations.

Production Potential and Development of a Decision Support Models for the Plantations of Aleppo Pine in the Oued Laou Watershed in the Moroccan Rif

The present study was carried out in the Oued Laou watershed belonging to the Moroccan Rif. It aims at the elaboration of mathematical tariffs for cubing Aleppo pine, the morphometric and increments study. The data analyzed for this purpose were collected after a preliminary stratification of the forest based on the plantation age. The study of the region’s climate shows that the western sector of the watershed is part of the temperate humid bioclimate, and the eastern sector belongs to the warm variant subhumid. The analysis of the stand-study structure shows that the distribution of the number of stems as a function of the circumference is a distribution close to normal. Cubic rates have been constructed to estimate the volume of trees. The mean annual volume increment of Aleppo pine varies between 3.10 and 4.83 m3/ha/year from one plot to another; this small fluctuation largely reflects the homogeneity of the study area. Aleppo pine has a wide ecological and spatial plasticity: colonization of all substrates, bioclimates ranging from semi-arid to temperate humid. It’s a species that exhibits uniform behavior despite topographic and edaphic variations.

Carbon and Nitrogen Stable Isotope Abundances and Soil Stoichiometry of Zanthoxylum Planispinum Var. Dintanensis Plantations at Different Ages

Background and aimsUnderstanding the relationship between carbon, nitrogen and their stable isotope 13C, 15N and soil stoichiometry may assist to reveal the distribution pattern and stability mechanism of nutrient elements in karst ecosystem.MethodsFour plantations of Zanthoxylum planispinum var. dintanensis (5–7, 10–12, 20–22 and 30–32 years) in the karst plateau gorge area of Guizhou Province, China, were selected as the research objects to clarify the variation characteristics and interaction effects of leaf, litter, soil C, N and their isotopes with plantation age, and to explore the relationship between soil stoichiometry and the 13C, 15N of Zanthoxylum planispinum var. dintanensis plantation.Results(1) the 13C in leaf, litter and soil were − 28.04‰±0.59‰, -26.85‰±0.67‰ and − 19.39‰±1.37‰, respectively, correspondingly, the contents of 15N were 2.01‰±0.99‰, 2.91‰±1.32‰ and 3.29‰±0.69‰, respectively. The contents of the 13C and 15N can be rank ordered as soil > litter > leaf; (2) with the increase of plantation age, the soil 13C decreased; the leaf and litter 15N increased first then decreased; the litter 13C and soil 15N did not vary significantly; (3) the litter layer positively correlated to soil 13C, and negatively correlated to 15N; (4) redundancy analysis showed that soil microbial biomass carbon (MBC) and bacteria/fungi (BAC/FUN) were the dominant factors affecting C and N isotope natural abundances.ConclusionsThis study indicated that the species and acidity of soil microbial can affect the C and N isotope natural abundance.

The influence of factors on the yields of two raspberry varieties (Rubus idaeus L.) and the economic results

The research was carried out in the years 2015–2018 on the commercial plantations of a horticultural farm. The analysis focused on the yields of two raspberry cultivars: ‘Polana’ and ‘Polka’, factoring in the influence of cultivation methods (in the ground; in the beds with an agrotextile), soil classes (IIIa; IVb), and plantation age (2–5 and 6–10 years). The commercial yields of fruit intended for processing were determined. The economic efficiency analysis of the production of both varieties was carried out. It was shown that regardless of the factor under scrutiny, higher results (in t·ha–1) were obtained from the ‘Polana’ variety. There were differences in the yields of the two varieties depending on the factors. In the case of both varieties, higher results were obtained in traditional cultivation and in class IIIa soil. The plantation age caused only slight differences in the yields of both varieties. The analyses showed statistical significance only in the case of the impact of the cultivation method on the yields of the ‘Polana’ cultivar. Regardless of the variety, the value of production decreased year after year, which resulted mainly from the downward trend in raspberry prices.

Eucalyptus plantations in temperate grasslands: responses of taxonomic and functional diversity of plant communities to environmental changes

ABSTRACTUnderstanding how human land-uses impact on local communities is required to implement management and conservational policies and practices. Tree plantations have become one of the fastest-growing land uses in recent decades and their impact on biodiversity was evaluated mainly at the taxonomic level. Our aim was to analyze the effects of changes in environmental drivers along the 12 years eucalypt plantations chronosequence on alfa, beta, taxonomic and functional diversity of understory plant communities. We selected nine plantation ages with three replicates per age and three protected grasslands as reference habitat. At each replicate, we established three plots to measure plant species cover and environmental variables, which are expected to change with plantation age. Results showed that species richness and all diversity indices significantly declined with increasing plantation age. Canopy cover, soil pH, and leaf litter were the most important drivers that explained the decline in taxonomic and functional diversity of plants through the forest plantation. Based on the Path analyses results, canopy cover had an indirect relationship with plant functional diversity mediated by leaf litter, soil pH and plant species richness. The results of the association between functional traits and environmental variables have revealed that high dispersal potential, annual, barochorous, and zoochorous plant species were the functional traits more affected by the eucalypt plantations. Given that leaf litter was negatively associated with all diversity facets, we recommend reducing their accumulation within eucalypt plantation to enhance biodiversity conservation and the provision of pampean grassland ecosystem functions.

Influence of Pinus pinaster age on aluminium fractions in acidic soils

The influence of plantation age on the chemical properties of acidic soils was studied in 16 plots in adult <em>Pinus pinaster</em> stands established in Galicia (NW Spain). The Al fractions in the soil solid phase and the total Al in soil solution were determined in the upper soil layer (0-20 cm) and the lower soil layer (20-40 cm) in each plot. The pH, total C and N, exchangeable Ca, Mg, Na, K, and Al and Al saturation (% Al) were determined in the solid fraction. Aluminium was extracted from the solid phase with the following solutions: ammonium oxalate (Al_o), sodium pyrophosphate (Al_p), copper chloride (Al_cu) and ammonium chloride (Al_NH4). The total Al in the liquid phase was also determined. All soil chemical parameters, except total N, C/N ratio and % Al, were significantly influenced by soil depth. The mean pH was lower in the upper than in the lower layer (4.57 vs. 4.97), but the opposite was observed for the organic C (77.2 vs. 50.4 g kg^-1), the effective cation exchange capacity (eCEC) (9.43 vs. 6.25 cmol₍₊₎ kg^-1), P (8.95 vs. 4.65 mg kg^-1) and the exchangeable cations. Organic matter, total N and eCEC were significantly and positively correlated with plantation age (r = 0.69 in the upper layer and r = 0.82 in the lower layer, p &lt; 0.01; r = 0.62, p &lt; 0.05 in the upper layer and r = 0.78, p &lt; 0.01 in the lower layer; r = 0.77, p &lt; 0.01 in the upper layer and r = 0.85, p &lt; 0.0001 in the lower layer, respectively), and pH_KCl was negatively correlated with plantation age (r = -0.55 in the upper soil layer and r = -0.61 in the lower soil layer, p &lt; 0.05). The concentrations of the different Al forms in all soils decreased in the order Al_p&gt; Al_o&gt; Al_cu&gt; Al_NH4. Highly stable organo-aluminium complexes (Al_p-cu) predominated over moderate and low stability complexes (Al_cu) in all soil plots. The highly stable organo-Al complexes were significantly more abundant in the lower layer, whereas the opposite was observed for the exchangeable Al and the total Al in soil solution. The concentrations of all Al forms (except Al_p-cu) were significantly and positively correlated with plantation age (Al_o r = 0.50, p &lt; 0.05 for the upper layer and r = 0.67, p &lt; 0.01 for the lower layer; Al_p r = 0.64, p &lt; 0.01 for the lower layer; Al_cur = 0.84 for the upper layer and r = 0.83 for the lower layer, p &lt; 0.0001; Al_cu-NH4 r = 0.65 for the upper layer and r = 0.78 for the lower layer, p &lt; 0.01; Al_NH4 r = 0.76, p &lt; 0.01 for the upper layer and r = 0.84, p &lt; 0.0001 for the lower layer; total Al in soil solution r = 0.61 for the upper layer and r = 0.60 for the lower layer, p &lt; 0.05). Stepwise linear regression analysis showed that plantation age, pH and total C explained between 67% and 93% of the variance in the Al forms. In all regression models, plantation age was a significant predictor variable for the different Al fractions, except total soluble Al, which is an important variable to consider in the study of chemical properties in forest soils.

Age and Species of Eucalyptus Plantations Affect Soil Microbial Biomass and Enzymatic Activities

Soil microorganisms and extracellular enzymes play important roles in soil nutrient cycling. Currently, China has the second-largest area of eucalyptus plantations in the world. Information on the effects of eucalyptus age and species of trees on soil microbial biomass and enzyme activities, however, is limited. In this paper, the soil microbial biomass and enzyme activities were studied in eucalyptus plantations with different ages (1 and 5+ years) and species of trees (E. urophylla×E. grandis, E. camaldulens and E. pellita) in South China. The results showed that both plantation age and eucalyptus species could affect the total microbial biomass and fungal biomass, whereas the bacterial biomass was affected only by plantation age. The fungal biomass and the fungi-to-bacteria ratio significantly increased along with increasing plantation age. Similarly, the plantation age and eucalyptus species significantly affected the enzyme activities associated with carbon cycling (β-xylosidase, β-d-glucuronidase, β-cellobiosidase and β-glucosidase). The activities of β-d-glucuronidase and β-glucosidase were significantly higher in the E. camaldulens plantation. The enzymes involved in nitrogen (N-acetyl-glucosamidase) and sulfur (sulfatase) cycling were only affected by the eucalyptus plantation age and species, respectively. The results highlight the importance of the age and species of eucalyptus plantations on soil microbial activities.