Saprotrophic mycelial cord abundance, length and survivorship are reduced in the conversion of tropical cloud forest to shaded coffee plantation

One of the most conspicuous soil elements of the tropical cloud forest in central Veracruz, mycelial cord-forming fungi, is strongly affected by the conversion of forest into shaded coffee plantations. Mycelial cord-forming fungi are less abundant, smaller and have a sharper mortality rate in shaded coffee plantations than in relatively conserved forest sites. I present evidence that suggests that changes in soil microenvironmental conditions affect the abundance of mycelial cord forming fungi. These results lend further support to growing evidence that the biodiversity of the understorey and soil are not being conserved within shaded coffee plantations. This contrasts markedly with other studies that suggest that over storey biota is effectively conserved by this conversion.     

Transition from Forest‐based to Cereal‐based Agricultural Systems: A Review of the Drivers of Land use Change and Degradation in Southwest Ethiopia

The southwestern Ethiopian montane forests are one of the most species‐rich ecosystems and are recognised globally as a priority area for the conservation of biodiversity. Particularly, in contrast to the drier central and northern Ethiopian highlands, they have received little attention by researchers. Here, we review changes to agricultural systems in and around these forests that are known as the genetic home of coffee (Coffea arabica L.) and that are important to the livelihoods of many rural people who have developed traditional management practices based on agro‐ecological knowledge, religious taboos and customary tenure rights. We explored the impacts of conversions to agroforestry and cereal‐based cropping systems on biodiversity, soil fertility, soil loss and the socio‐economic conditions and culture. The increasing trend of cereal cropping, resettlement and commercial agriculture causes the deterioration of natural forest cover in the region and threatens biodiversity, land quality, sustainable, traditional farming practices and the livelihood of the local community. Large‐scale plantations of tea, coffee, soapberry locally known as endod (Phytolacca dodecandra L'Hér.) and cereals have resulted in biodiversity loss. Following the conversion of forests, cultivated fields exhibit a significant decline in soil fertility and an increase in soil loss as compared with the traditional agroforestry system. The establishment of a sustainable agricultural system will require a change in paradigm, whereby the intrinsic values of the traditional forest‐based agricultural system are recognised, rather than the ongoing mimicking of agricultural policies that were developed for the open fields of central Ethiopia. Copyright © 2016 John Wiley & Sons, Ltd.     

Spatial patterns of grasses influence soil macrofauna biodiversity in Amazonian pastures

Grasslands are often characterized by small-scale spatial heterogeneity due to the juxtaposition of grass tufts and bare ground. Although the mechanisms generating plant spatial patterns have been widely studied, few studies concentrated on the consequences of these patterns on belowground macrofauna. Our objective was to analyze the impact of grass tuft (Brachiaria bryzantha cv. marandu) spatial distribution on soil macrofauna diversity in Amazonian pastures, at a small scale (less than 9 m²). Soil macrofauna was sampled among B. bryzantha tufts, which showed a variable spatial distribution ranging from dense to loose vegetation cover. The vegetation configuration explained 69% of the variation in total soil macrofauna density and 68% of the variation in total species richness. Soil macrofauna was mainly found in the upper 10 cm of soil and biodiversity decreased with increasing distances to the nearest grass tuft and increased with increasing vegetation cover. The size of the largest grass tuft and the micro-landscape connectivity also had a significant effect on biodiversity. The density and species richness of the three principal soil ecological engineers (earthworms, ants and termites) showed the best correlations with vegetation configuration. In addition, soil temperature significantly decreased near the plants, while soil water content was not influenced by the grass tufts. We conclude that soil macrofauna diversity is low in pastures except close to the grass tufts, which can thus be considered as biodiversity hotspots. The spatial arrangement of B. bryzantha tussocks influences soil macrofauna biodiversity by modifying soil properties in their vicinity. The possible mechanisms by which these plants could affect soil macrofauna are discussed.     

Solubilization of iron and calcium phosphates by soil fungi isolated from coffee plantations

Almost 900 fungal isolates were obtained from eight coffee plantations in Colombia and Mexico. Of these, 76 isolates showed activity to solubilize Ca₃(PO₄)₂ (PCa) and FePO₄·H₂O (PFe), which had been added to agar in a plate test. Generally, PCa was better solubilized than PFe. Colombian isolates were generally somewhat less effective than Mexican isolates. The two most effective isolates from each country with apparent highest PFe, solubilization potential were selected and cultivated in liquid medium containing PFe, which is more prevalent in tropical soils. The pH value, solubilized P in the medium and P uptake in fungal biomass were determined. After 24 days, Cylindrocarpon didymum and C. obtusisporum (both from Colombia) had solubilized 9.9 and 6.4 mg PO₄ ^3--P L^?1 and took up 8.6 and 11.6 mg P in biomass. Penicillium janthinellum and Paecilomyces marquandii (both from Mexico) solubilized 7.0 and 1.9 mg PO₄ ^3--P L^?1 and took up 11.3 and 17.3 mg P in biomass. The potential practical use of the four fungal isolates for different strategies in making more P available for coffee growth is discussed.     

云南咖啡种植区土壤养分状况及影响咖啡生豆品质的主要因素

【目的】为深入了解云南主要咖啡产区的土壤养分状况及其对咖啡生豆品质的影响,本文对云南主要咖啡产区的土壤及咖啡生豆进行了采样分析。【方法】在云南咖啡种植区共采集咖啡生豆样品38份、土壤混合样品49个,土壤采样深度为0—20 cm。测定了土壤有机质、pH、碱解氮、有效磷和速效钾含量,分析了咖啡生豆中灰分、咖啡因、总糖、还原糖和脂肪含量。根据土壤样品中各项养分指标确定其隶属函数类型及阈值,采用主成分分析法求得各指标的权重,运用加乘法算出各土样的土壤肥力综合指标值(IFI),并将IFI值采用欧氏距离聚类方法进行聚类,然后根据IFI值对每个聚类等级进行定义,最后用典型相关分析的方法分析咖啡生豆品质与土壤养分之间的关系。【结果】云南各咖啡种植区的土壤综合肥力存在显著变化(P <0.05),IFI值主要位于0.43~0.67之间,均值为0.53。IFI值聚类结果可将土壤肥力分为4类,Ⅰ类为适宜(0.55~0.67)、Ⅱ类为一般(0.43~0.53)、Ⅲ类为差(0.35~0.39)、Ⅳ类为较差(0.24~0.29)。Ⅰ类和Ⅱ类占咖啡种植区域面积的98.8%,其中第Ⅰ类占54.2%,主要分布于德宏与普洱地区;第Ⅱ类占44.6%,主要分布于临沧和保山地区。各区域IFI值的大小顺序为德宏(0.64)>普洱(0.58)>临沧(0.46)>保山(0.43)。咖啡生豆品质与土壤养分指标有着显著的典型相关关系(P <0.05),影响咖啡风味的咖啡因和总糖含量随着土壤速效钾的升高呈降低趋势;而影响咖啡醇厚度的脂肪含量则随着土壤pH值和碱解氮的升高而降低。【结论】云南主要咖啡产区的土壤养分状况适宜咖啡生长,土壤综合肥力一般。土壤速效钾、碱解氮含量和pH值对咖啡生豆品质有重要影响,其含量过高或过低均可能降低咖啡生豆的品质。     

Phyllostomid bat diversity in a variegated coffee landscape

We examined bat diversity at two different spatial scales: habitat and matrix, in the Quindío coffee region in Colombia. Habitats were: forest, shaded coffee and associated coffee; and matrices were: associated coffee (M1) and shaded coffee (M2). Three sampling sites from each type of habitat were located at each matrix. The forest areas of the Quindío region are severely fragmented and less structurally complex than coffee patches. The shaded coffee habitat had patches that were larger and more complex. In spite of limited patch size and lower complexity, the forest remnants were those with greatest species richness and demonstrated clear similarities even between the two matrices. This was not observed in coffee plantations, neither in associated coffee nor shaded coffee. On the landscape scale, M2 showed lower β diversity and greater edge density (ED) than M1. This fact explains that greater connectivity between different habitats exists in M2 than in M1. Our results suggest that production and conservation are compatible, as maintenance of forest remnants in a mosaic structure by landowners of the vegetation is sufficient to conserve phyllostomid bats at landscape level.     

Landscape analysis of dynamic soil erosion in Subtropical China: A case study in Xingguo County, Jiangxi Province

As a case study on landscape pattern analysis of soil erosion change, Xingguo County in Jiangxi Province, China, was once one of the most severely eroded regions in Subtropical China. However, its soil erosion has been completely controlled in recent years. This county was historically full of forest as well as waterways that were well protected and soil erosion was seldom seen even by the mid-19th century. However, large areas of forest were destroyed after that period due to over-logging, which resulted in excessive erosion, bare hills, and mountains devoid of vegetation. Fortunately, soil erosion in Xingguo has been controlled gradually since 1982 after the county was appointed as 1 of the 8 Key National Level Erosion Control Regions. In this study, a raster (grid) soil erosion map was collected on the basis of soil erosion intensity maps from 1958, 1975, 1982 and 2000 with the aid of GIS software (ARC/INFO). Over 10 landscape indices were calculated using FRAGSTATS software for landscape pattern analysis. A set of free spatial statistics that address a fundamental problem in GIS, and soil erosion distribution patterns and their changes in the county were quantitatively analyzed at the landscape and class levels, respectively. Moreover, transformations of soil erosion types from 1958 to 1975, 1975 to 1982, and 1982 to 2000 were also calculated using the CROSSTAB module in IDRISI software. Results showed that at the landscape level, heterogeneity of soil erosion decreased. This was supported by decreasing tendencies of patch indices SHDI (Shannon’s diversity index), SHEI (Shannon’s evenness index), and IJI (Interspersion and juxtaposition index). This indicates that most of the severely eroded soil types were transformed into non-apparently eroded or slightly eroded types. Meanwhile, at the class level, a consistent pattern was found where the surface areas of non-apparently eroded or slightly eroded lands increased, and moderately, severely, very severely and extremely eroded lands deceased. In general, soil erosion in Xingguo County experienced three pronounced phases during the study periods: the exacerbation phase (1958–1975), the alleviation phase (1975–1982), and the overall alleviation phase (1982–2000). By the year 2000, 74.6% of total territory of this county was covered by land with no significant soil loss, indicating that severe soil erosion had been substantially controlled.     

Coffee mucilage impact on young coffee seedlings and soil microorganisms

A greenhouse pot experiment was carried out to assess the effects of fermented coffee mucilage applied as mulch together with maize leaves on the growth of young coffee plants of two different varieties and on soil microbial biomass indices. The coffee variety Catuai required 32% more water per g plant biomass than the variety Yellow Caturra, but had a 49% lower leaf area, 34% less shoot and 46% less root biomass. Maize and mucilage amendments did not affect leaf area, shoot and root yield, or the N concentration in shoot and root dry matter. The amendments always reduced the water use efficiency values, but this reduction was only significant in the maize+mucilage‐14 (= 14 g mucilage pot^?1) treatment. Soil pH significantly increased from 4.30 in the control to 4.63 in the maize+mucilage‐14 treatment. Microbial biomass C increased by 18.5 µg g^?1 soil, microbial biomass N by 3.1 µg g^?1 soil, and ergosterol by 0.21 µg g^?1 soil per g mucilage added pot^?1. The presence of mucilage significantly reduced the microbial biomass‐C/N ratio from a mean of 13.4 in the control and maize treatments to 9.3, without addition rate and coffee variety effects. The application of non‐composted mucilage is recommended in areas where drought leads to economic losses and in coffee plantations on low fertility soils like Oxisols, where Al toxicity is a major constraint.     

A multi-scale study of soil macrofauna biodiversity in Amazonian pastures

The influence of three spatially hierarchical factors upon soil macrofauna biodiversity was studied in four pasture plots in eastern Amazonia. The first factor was the local depth of the soil. The second factor was the ground cover type on the soil samples (bare ground, grass tufts, dead trees lying on the ground). The third factor was the dimensions of the grass tufts sampled (size and shape). The effect of each factor upon the morphospecies richness and density of total soil macrofauna was analysed. Detailed results are given for earthworms, termites, ants, beetles and spiders. All factors significantly affected the morphospecies richness and/or density of the soil macrofauna. The type of ground cover had the strongest influence, affecting the total richness and density of the soil macrofauna and of almost all the groups represented. The soil depth affected only the density of the termites and the global morphospecies richness. Interactions between soil depth and ground cover type affected the total macrofauna morphospecies richness and the density of the earthworms. The dimensions of the grass tuft influenced the global morphospecies richness, the morphospecies richness of the ants and the density of the spiders.     

Soil macroinvertebrate communities and ecosystem services in deforested landscapes of Amazonia

Land use changes in the Amazon region strongly impact soil macroinvertebrate communities, which are recognized as major drivers of soil functions (Lavelle et al., 2006). To explore these relations, we tested the hypotheses that (i) soil macrofauna communities respond to landscape changes and (ii) soil macrofauna and ecosystem services are linked. We conducted a survey of macrofauna communities and indicators of ecosystem services at 270 sites in southern Colombia (department of Caqueta) and northern Brazil (state of Pará), two areas of the Amazon where family agriculture dominates. Sites represented a variety of land use types: forests, fallows, annual or perennial crops, and pastures. At each site we assessed soil macroinvertebrate density (18 taxonomic units) and the following ecosystem service indicators: soil and aboveground biomass carbon stock; water infiltration rate; aeration, drainage and water storage capacities based on pore-size distribution; soil chemical fertility; and soil aggregation. Significant covariation was observed between macrofauna communities and landscape metric data (co-inertia analysis: RV = 0.30, p < 0.01, Monte Carlo test) and between macrofauna communities and ecosystem service indicators (co-inertia analysis: RV = 0.35, p < 0.01, Monte Carlo test). Points located in pastures within 100 m of forest had greater macrofauna density and diversity than those located in pastures with no forest within 100 m (Wilcoxon rank sum test, p < 0.01). Total macroinvertebrate density was significantly correlated with macroporosity (r² = 0.42, p < 0.01), as was the density of specific taxonomic groups: Chilopoda (r² = 0.43, p < 0.01), Isoptera (r² = 0.30, p < 0.01), Diplopoda (r² = 0.31, p < 0.01), and Formicidae (r² = 0.13, p < 0.01). Total macroinvertebrate density was also significantly correlated with available soil water (r² = 0.38, p < 0.01) as well as other soil-service indicators (but with r² < 0.10). Results demonstrate that landscape dynamics and composition affect soil macrofauna communities, and that soil macrofauna density is significantly correlated with soil services in deforested Amazonia, indicating that soil macrofauna have an engineering and/or indicator function.     

Ants as indicators of soil-based ecosystem services in agroecosystems of the Colombian Llanos

Ants represent a widespread and functionally diverse taxonomic group that are both sensitive to land management and serve as important regulators of key soil processes. Building upon this idea, we sought to understand the impacts of agricultural management on ant communities in the Orinoco River Basin of eastern Colombia and to identify species that could be used as indicators of soil-based ecosystem services. Ants were collected and identified from the soil and litter layer within 75 fields (nine TSBF sub-samples along a transect in each field) divided among five common agricultural land uses in the region: 1) annual crops (maize, soy and rice), 2) rubber plantations, 3) oil palm plantations, 4) improved pastures (based on Brachiaria spp.), and 5) semi-natural savannas. As expected, land management was found to greatly influence ant communities. Improved pastures showed the highest species richness (6.9 species per transect) and semi-natural savanna the greatest abundance of ants (145 individuals per transect). Within each of these fields a suite of soil and agroecosystem characteristics were measured and combined into synthetic indicators of five soil-based ecosystem services: 1) nutrient provision, 2) water storage and regulation, 3) maintenance of soil structure, 4) climate regulation services and 5) soil biodiversity and biological activity. Ant species were then associated with these synthetic indicators using the IndVal method to identify indicator species for each of the five consolidated ecosystem services measured. In total, 14 indicator species were identified and found to be significantly associated with either the high or low provision of each of the five services. The development of such bioindicators offers a rapid and relatively inexpensive tool to facilitate land management and policy decisions in this biologically diverse and rapidly changing region of Colombia.     

Soil and phosphorus redistribution along a steep tea plantation in the Feitsui reservoir catchment of northern Taiwan

Abstract

Feitsui reservoir, the major water supply of Taipei city, has shown declining water quality in recent years. The reservoir is located in an area famous for tea cultivation, and the question arises as to whether the hillside tea plantations have contributed to increased sediment and nutrient discharge into the reservoir. In this study, soil and phosphorus redistribution were examined along a steep tea plantation in the reservoir's catchment and the provenance of reservoir sediment was assessed. Fallout radionuclides were used as soil erosion/deposition tracers and as markers of sediment sources. Continuous fertilizer application has raised (inorganic) phosphorus levels in the studied tea plantation. The plantation's narrow bench terraces trap eroded material and slow down soil and nutrient translocation. Nevertheless, eroded soil and phosphorus have accumulated on a vegetated toeslope below the tea plantation. The reservoir sediment contained significant amounts of inorganic phosphorus and cesium-137, and application of a mixing model resulted in a surface soil contribution of approximately 30%. This points towards tea plantations as possible sediment and pollutant sources and underlines the necessity of soil conservation strategies, such as the maintenance of vegetated riparian buffer zones. However, other sources, such as landslide debris and urban wastewaters, cannot be entirely ruled out. Further research is needed to better characterize the catchment's soils and sediments and to improve sediment fingerprinting efforts. Potential point and non-point pollution sources need to be examined in detail to better understand how phosphorus enters the reservoir.     

Migratory songbird use of shade coffee in the Venezuelan Andes with implications for conservation of cerulean warbler

Although previous studies have demonstrated high use of shade coffee plantations by Neotropical migratory birds, we still have a poor understanding of the suitability of shade coffee plantations as habitat on the wintering grounds. We studied density, body condition, and survivorship of Neotropical migrants, with emphasis on cerulean warbler (Dendroica cerulea), in primary forest and shade coffee plantations in Venezuela. We worked in three primary forest sites and three shade coffee plantations on the western slope of the Cordillera de Mérida of the Andes Mountains. At each site, we surveyed migrants with distance-based line transects and mist-netted and banded migrants during November–February 2005/06 and 2006/07. In addition, we estimated apparent monthly survival for cerulean warbler based on 29 color-banded individuals. Densities of migrants were 3–14× higher in shade coffee plantations than primary forest sites, even after accounting for differences in detectability. Apparent monthly survival of cerulean warblers was estimated at 97% and overwinter persistence was similarly high. In addition, cerulean warblers demonstrated high between-season fidelity, with 65% of the birds banded the first year being resighted during the second year. Interestingly, immature birds returned at nearly half the rate as did adults. Banding data indicated that body condition increased significantly as the season progressed for cerulean warblers, Tennessee warblers (Vermivora peregrina), and American redstarts (Setophaga ruticilla). Collectively, these data provide evidence that shade coffee plantations offer high quality wintering habitat for Neotropical migrants, including cerulean warblers.     

水土保持措施对板栗林土壤呼吸的影响

为阐明板栗林土壤呼吸对水土保持措施的响应,采用IRGA法,对不同类型板栗林的土壤呼吸从2009年3月至2010年9月开展为期1年半的定位观测。结果表明:1)采取水土保持措施后,样地的土壤水分状况得到一定程度的改善,尤其随着采取水土保持措施年限的延长,其对土壤水分时空分布影响更为显著。2)4个板栗林样地的土壤呼吸速率均呈明显的单峰曲线变化,水土保持措施对土壤呼吸的季节动态无明显影响。3)样地Ⅰ和Ⅲ的参考呼吸R10分别为1.718和1.595μmol/(m2.s);而采取水土保持措施后,样地Ⅱ和Ⅳ的R10均表现为一定程度的降低,分别为1.092和1.324μmol/(m2.s)。样地Ⅰ和Ⅲ的土壤呼吸的温度敏感性指数Q10分别为1.927和1.899;采取水土保持措施后,样地Ⅱ和Ⅳ的Q10均表现为略微增加。采取水土保持措施后,土壤温度和土壤湿度对土壤呼吸速率的影响有一定程度的增强。研究结果可为把水土保持措施作为土壤严重侵蚀地区一种潜在的固碳减排模式提供基础数据。     

Soil fauna abundance and diversity in a secondary semi-evergreen forest in Guadeloupe (Lesser Antilles): influence of soil type and dominant tree species

The importance of secondary tropical forests regarding the maintenance of soil fauna abundance and diversity is poorly known. The aims of this study were (1) to describe soil fauna abundance and diversity and (2) to assess the determinants of soil fauna abundance and diversity in two stands of a tropical semi-evergreen secondary forest. Soil macrofauna and microarthropod abundance and soil macrofauna diversity were described at two sites developed on different soils and with different site histories: (1) a natural secondary stand (natural forest) under two dominant tree species, Pisonia subcordata and Bursera simaruba, and (2) a planted secondary forest (planted forest) under three tree species, B. simaruba, Swietenia macrophylla, and Tabebuia heterophylla. The effects of both soil and main tree species’ litter quality were assessed to explain soil fauna abundance and diversity. The abundance of soil macrofauna was significantly higher in the soil under the planted forest, and soil fauna communities were contrasted between the two sites. In the planted forest, a soil-dwelling macrofauna community developed (mainly consisting of the anecic earthworm Polypheretima elongata). In the natural forest, soil macrofauna and microarthropod communities were located at the soil surface. The effect of plant litter quality varied according to each dominant tree species and was superimposed to soil effect. The lowest macrofauna abundance was associated with B. simaruba in the natural forest. T. heterophylla supported a much greater macrofauna community than the two other tree species studied at the same soil, and it appears likely that this is due to the palatability of its leaves compared with the other trees (low lignin, tannins, soluble phenols).     

Diversity of <Emphasis Type="Italic">Ullucus tuberosus</Emphasis> (Basellaceae) in the Colombian Andes and notes on ulluco domestication based on morphological and molecular data

Ullucus tuberosus (common name ‘ulluco’) is a popular tuber crop of Andean highlands. Until now attention has been focused on ulluco from Bolivia, Peru and Ecuador, but little is known about its diversity in Colombia. Thirty-six accessions of cultivated ulluco preserved in the Gene Bank of the Universidad Nacional de Colombia were studied to assess the genetic diversity and spatial genetic structure of Colombian ulluco. We used morphological characters, molecular markers (total proteins, isozymes and RAPDs) and ploidy level. High morphological variability, especially for tuber shape and colour characters, was found. Eight accessions from north-east Colombian Andes showed some typical character-states of wild ulluco, suggesting that they could be partially domesticated forms. Genetic analysis using RAPD markers indicated that these accessions were very similar to other cultivated ullucos belonging to the same region. The regional structure observed in isozyme and RAPD dendrograms was confirmed by AMOVA results (52.6% among-region variation) and the spatial correlogram, showing the presence of two gene pools of ulluco in Colombia. Our results and the accumulated data suggest that ulluco was introduced to Colombia at least two times. Initially, semi-domesticated forms would have come from the central Andes to north-east Colombian Andes, where the native inhabitants would have completed the domestication process. Again, fully domesticated ullucos might have been introduced to south-west Colombian Andes.     

米亚罗林区冬季大型土壤动物的空间分布特征

土壤动物是陆地生态系统的组成部分,对多种地下生态过程具有重要的作用[1-2]。近些年,对土壤动物多样性及其功能的研究已成为生态学领域的一个新兴前沿[3-4]。土壤动物群落组成对植被变化有明显的依赖性,不同植被类型有着与其相适应的土壤动物群落[5-7]。但植被类型的变化常与海拔     

Long‐term Effects of Pine Plantations on Soil Quality in Southern Spain

This work evaluated how pine plantations established on old fields and degraded lands influence soil properties in comparison with adjacent unplanted areas that undergo into secondary succession, and native forests, analysing the effects of abiotic variables and stand characteristics in the afforestation process. Thirty‐two paired sites (pine plantations versus unplanted areas) and 10 native forests were selected in the SE Spain. In total, 74 soil profiles were studied, and 222 composite soil samples were collected at three different depths. Soil organic carbon, cation exchange capacity, and C : N ratio showed significantly greater values in pine plantations in relation to the unplanted areas (0–5 cm), and the mean values of soil organic carbon, nitrogen (N), C : N ratio, and cation exchange capacity in these pine plantations were similar to those found under native forests. Only K⁺ concentrations were clearly higher in the native forests than in the other land uses for all depths analysed. Pine plantations in the drier and warmer areas showed lower soil quality in relation to the paired unplanted areas, as well as the younger and denser ones; it may be because under these situations, more time is needed to produce an improvement. In fact, the paired net variations increased with the stand age and/or tree size. In conclusion, pine plantations were in general more efficient in improving parameters related to soil quality, especially in locations with high soil water retention capacity, which in our study area were found at higher and cooler elevations. Copyright © 2016 John Wiley & Sons, Ltd.