Chamaedorea Elegans Research Articles

Characterization of production and commercialization systems of camedor palm (Chamaedorea elegans Mart.).

Objective: To describe the cultivation systems of C. elegans through the analysis of production and commercialization in three municipalities in the high mountain region of Veracruz, Mexico. Design/Methodology/Approach: The study was conducted in Tepatlaxco, Zongolica, and Omealca, Veracruz, Mexico. From January to July 2022, a survey was administered to 84 producers of Camedor palm using convenience sampling. In addition, interviews with key informants and participant observation were conducted. Results: Camedor palm production occurs in small production units ranging from 1 ± 0.05 to 7.0 hectares, primarily managed by male producers (93%) with an average age of 48 years and 6 years of schooling. Planting densities range from 35,000 to 100,000 plants per hectare, and leaf cutting is conducted on a quarterly basis, yielding between 1000 to 3700 rolls per hectare at an average price of $14.00 Mexican pesos per roll paid to the producer. Prior to cultivating Camedor palm, 56% of producers were growing coffee. The main driving factor for cultivation is the steady generation of income. Limitations/Implications: This is a specific case study; therefore, the results are limited to descriptive statements about the study area. Findings/Conclusions: Producers utilize non-timber forest products as alternatives to crises in other crops and investment constraints within production units. The production of C. elegans is accessible, requires low investment, and is compatible with family farming. However, yields in some cases are low, and the marketing network shows high intermediation.

First Report of Leaf Spot Disease on Chamaedorea elegans Caused by Fusarium oxysporum in China.

Chamaedorea elegans, native to Mexico and Guatemala, is a commonly planted indoor and small-scale garden ornamental due to its stately appearance, tolerance of low light levels, and its ability to improve air quality (El-Khateeb et al. 2010). In December 2021, an unknow leaf-spot disease was observed on C. elegans in Ganzhou City of Jiangxi Province, China (25.83 °N, 114.93 °E). The symptoms were small brown spots on the leaves, gradually expanded into irregular dark brown spots with necrotic tissue forming in the center of the lesions (Figure 2 A-1 and A-2). To isolate the pathogen, the diseased leaves were surface sterilized in 75% ethanol for 30 s. Small pieces of tissue (5 × 5 mm) were taken from the margin between diseased and healthy tissue, disinfected 1% NaClO for 45 s, washed three times in sterile water, and then placed on PDA at 25 ± 1°C for 5 days. Later, five isolates were purified from single spores and each of the five isolates has the same properties as described below. The isolates had abundant pale purple flocculent hyphae with purple pigmentation (Figure 2 C-1 and C-2). Macroconidia were falciform, straight or slightly curved, 1-2 septate, 11.75 to 22.99 × 3.06 to 4.44 μm (μ=16.08 μm × 3.37 μm, n=50) (Figure 2 D-1). Microconidia were oval or elliptical, a septate, 4.03 to 9.19 × 1.92 to 3.73 μm (μ=5.88 μm × 2.66 μm, n=50) (Figure 2 D-2). Chlamydospores formed singly or in pairs, and were terminal or intercalary in hyphae (Figure 2 D-3). Based on morphological characteristics, the fungus was preliminarily identified as a Fusarium sp. (Leslie et al. 2006). To confirm the identification, primers ITS1/ITS4 (White et al. 1990), RPB2-5f2/RPB2-7cr (O'Donnell et al. 2010; Liu et al. 1999) and TEF 1-αF/TEF 1-αR (O'Donnell et al. 2000) were used to amplify and sequence apportion of the ITS, RPB2 and TEF (Table 1). The sequences (Genebank accession number: OM780148, OM782679, OM782680) shared 100% idnetity with Fusarium oxysporum (Genebank accession number: MH866024.1, MH484930.1, MH485021.1). The maximum likelihood (ML) phylogenetic analysis of the concantenated ITS, RPB2 and TEF sequences was performed in MEGA7.0. (Sudhir et al. 2016), assigning the isoaltes to the F. oxysporum species complex (Figure 1). To confirm the pathogenicity, nine pots of healthy 3-year-old C. elegans plants were inoculated in the greenhouse (12 h light/12 h dark cycle, RH 90 %, three for wounded inoculation, three for nonwounded inoculation and three for control). Fifty disinfected leaves were wounded with sterile needles and fifty remained unwounded. The wounded (Figure 2 B-1 and B-2) and unwounded leaves were inoculated with a 10 μL spore suspension (1.0 × 106 conidia/ml) which was taken from each of the five isolates cultured for 7 days. Fifty leaves were mock-inoculated with sterile water (Figure 2 B-3 and B-4). After incubation for 7 days, the wounded leaves inoculated with the spore suspension had similar symptoms to the original diseased leaves, while the unwounded leaves and the control leaves did not develop symptoms. The experiment was repeated three times and the pathogens was reisolated from wound-inoculated leaves with the same morphological characteristics to the original pathogens, and identified as F. oxysporum by morphological and molecular analysis, completing Koch's postulates. F. oxysporum, a pathogen with a broad spectrum of hosts, ranks 5th among the top 10 fungal plant pathogens (Amjad et al. 2018.) and has been reported to Carpinus betulus, Citrullus lanatus, Pinus pinea (Mao et al. 2021; Muhammad et al. 2021; Monther et al. 2021). To our knowledge, this is the first report of leaf spot disease on C. elegans caused by F. oxysporum in China. C. elegans is an important ornamental plant in China with high economic value, so the disease has the potential to be a threat to its cultivation industry.

Effects of airflow rate and plant species on formaldehyde removal by active green walls.

Formaldehyde is a hazardous volatile organic compound (VOC) listed as a Group 1 carcinogen by the International Agency for Research on Cancer. The active green wall system is a promising technology that utilizes active airflow passing through plants grown along a vertical alignment to increase their mass exposure to pollutants. However, few studies have investigated the effect of airflow rate on their efficacy for formaldehyde removal, and plant-mediated effects are unknown. This study assessed the formaldehyde removal ability of the active green wall using dynamic experiments. Three levels of airflow rate (30, 50, and 65 m3·h-1) and inlet formaldehyde concentration (1.0, 2.0, and 3.5mg·m-3) were used and three plant species were investigated. The removal of formaldehyde by active green walls was significantly (P < 0.01) affected by the airflow rate, formaldehyde concentration, and plant species. The single pass removal efficiency varying from 38.18 to 94.42% decreased as the airflow rate and formaldehyde concentration increased. The elimination capacity varied from 189 to 1154mg·m-2·h-1 and increased with the inlet formaldehyde loading rate. Significant differences in formaldehyde removal effectiveness among the plant species were observed with Chlorophytum comosum performing the best, followed by Schefflera octophylla, with Chamaedorea elegans being the worst.

First report of tomato spotted wilt virus infecting parlor palm (Chamaedorea elegans) with leaf mosaic and ring spot disease in Korea

First report of tomato spotted wilt virus infecting parlor palm (Chamaedorea elegans) with leaf mosaic and ring spot disease in Korea

Palm Foliage as Pathways of Pathogenic Botryosphaeriaceae Fungi and Host of New Lasiodiplodia Species from Mexico.

Tropical palm foliage is increasingly imported to satisfy the steady growing demand in European floristry. This palm foliage presumably carries along diverse fungi whose taxonomic and functional diversity have not been addressed so far. The present study investigated Botryosphaeriaceae fungi associated with the foliage of palm species Chamaedorea elegans, C. metallica, C. seifrizii, Dypsis lutescens and Lodoicea maldivica imported from Mexico. Five species were identified using combined morphological characterisation and multilocus phylogenetic analyses based on ITS, TEF-1α, TUB2 and RPB2. In addition to Endomelanconiopsis endophytica, Lasiodiplodia brasiliensis and L. euphorbicola, two new species, namely, L. lodoiceae sp. nov. and L. mexicanensis sp. nov, are proposed. Apart from E. endophytica, mostly known as endophyte, L. brasiliensis and L. euphorbicola are responsible for different rot diseases and the dieback of important tropical crop plants. In pathogenicity tests on the temperate pome fruits apple (Malus domestica) and pear (Pyrus communis), all six Botryosphaeriaceae species induced necrotic lesions at different degrees of severity, with highest the aggressiveness from L. euphorbicola and L. mexicanensis on apple and from L. mexicanensis on pear. The results indicate that tropical palm foliage can be a pathway of potentially pathogenic fungi that may give rise to concerns with regard to plant health in the destination countries.

Modelling the phytoremediation of formaldehyde from indoor air by Chamaedorea Elegans using artificial intelligence, genetic algorithm and response surface methodology

Abstract Recently, indoor air quality has become a great concern for human health. Volatile organic compounds (VOCs), are the most common pollutants in the indoor air. Some VOCs such as formaldehyde are toxic and carcinogenic. A lot of researches have proved that potted plants through phytoremediation can help to reduce these pollutants, but modelling on these systems is not developed adequately and without creating the appropriate model, there will be no ability to predict the performance of phytoremediation. In this study, Formaldehyde removal from indoor air by Chamaedorea Elegans was modelled through Artificial Neural Networks (ANN) and Response Surface Methodology (RSM), and optimized by genetic algorithm (GA). Here, the formaldehyde concentration, leaf surface area, light intensity and relative humidity were considered as input variables. The experimental design was conducted using full factorial design method. The RSM results showed that the second-order nonlinear equation was in high accordance with the experiments. A Multilayer Perceptron ANN was developed and network performance was evaluated with several training algorithms, in which, the Levenberg Marquardt (LM) algorithm showed the best performance. Finally, the optimum value of the variables was determined by GA. The results indicated that the ANN model exhibits a higher degree of delicacy and accuracy compared to the RSM.

Leaf scattering polarimetry and chlorophyll fluorescence

A number of spectropolarimetry measurements on leaves using white light and narrow band illumination have been reported in recent years because of interest in signatures for remote sensing of exoplanet life. Chlorophyll fluorescence occurs in white light illuminated experiments and is known to be polarised and so might contaminate surface scattering measurements. A displacing filter experiment was performed on the leaves of two common plants, Ficus benjamina and Chamaedorea elegans, to estimate the contribution of chlorophyll fluorescence in the spectropolarimetry of leaf scattering and transmission. Chlorophyll fluorescence is present as a measurable polarised component of up to 15% of scattered and transmitted light for the leaf samples. Other effects emerged which indicate that in vivo measurements on leaves are subject to the responsive nature of the leaves to changes in colour and intensity of the incident light.

Long-term enrichment with the camedor palm (Chamaedorea elegans Mart.) improved forest cover in an anthropogenic tropical landscape

The use of non-timber forest products forms part of the strategy contributing to the well-being of populations near forest areas. Chamaedorea is one of the most important palm genera that is globally commercialized profitably for its attractive foliage used in floral decorations. In our study area located in the central region of Veracruz, Mexico we identified changes in tree cover between 1973 and 2017 using the normalized difference vegetation index (NDVI). We conducted plant surveys to identify tree species richness associated with the cultivation of C. elegans. We conducted semi-structured interviews with local palm producers to understand their perceptions regarding changes in tree cover in the study area and its association with the presence of the camedor palm. Soil cover patterns and vegetation index signatures indicated an increase in the forested area from 1973 to 2017 (after more than 43 years), with a 69% gain in secondary vegetation coverage with low NDVI values. This increase is associated with the cultivation of palm, since arboreal cover had previously been dominated by species traditionally used as shade for camedor cultivation. Tree diameters at breast height (DBH) were low, indicating young secondary forests with low recruitment and diversity in the understory suggestive of simplified species assemblages; most of the associated species were long-living pioneers and typical of the secondary forest favored by the palm producers. Producers mentioned they did not remove coffee because it is their main means of subsistence, and in combination with the palm, there is greater economic benefit. They also confirmed an increase in forest cover owing to the introduction of palm cultivars in the areas north and south of the study area. This was confirmed with the NDVI results, which detected the same spatial pattern. These changes resulted in the interruption of the processes of succession without the transition of secondary to old-growth forests. However, the canopy of the study area provides better environmental services than did the previously existing vegetation cover. This study showed the need for the assessment of non-timber forest products as key indicators of land use change and alterations in associated plant cover.

Heritability of growth and leaf loss compensation in a long-lived tropical understorey palm.

IntroductionDefoliation and light competition are ubiquitous stressors that can strongly limit plant performance. Tolerance to defoliation is often associated with compensatory growth, which could be positively or negatively related to plant growth. Genetic variation in growth, tolerance and compensation, in turn, plays an important role in the evolutionary adaptation of plants to changing disturbance regimes but this issue has been poorly investigated for long-lived woody species. We quantified genetic variation in plant growth and growth parameters, tolerance to defoliation and compensation for a population of the understorey palm Chamaedorea elegans. In addition, we evaluated genetic correlations between growth and tolerance/compensation.MethodsWe performed a greenhouse experiment with 711 seedlings from 43 families with twelve or more individuals of C. elegans. Seeds were collected in southeast Mexico within a 0.7 ha natural forest area. A two-third defoliation treatment (repeated every two months) was applied to half of the individuals to simulate leaf loss. Compensatory responses in specific leaf area, biomass allocation to leaves and growth per unit leaf area were quantified using iterative growth models.ResultsWe found that growth rate was highly heritable and that plants compensated strongly for leaf loss. However, genetic variation in tolerance, compensation, and the individual compensatory responses was low. We found strong correlations between family mean growth rates in control and defoliation treatments. We did not find indications for growth-tolerance/compensation trade-offs: genetic correlation between tolerance/compensation and growth rate were not significant.ImplicationsThe high genetic variation in growth rate, but low genetic variation in tolerance and compensation observed here suggest high ability to adapt to changes in environment that require different growth rates, but a low potential for evolutionary adaptation to changes in damage or herbivory. The strong correlations between family mean growth rates in control and defoliation treatments suggest that performance differences among families are also maintained under stress of disturbance.

Decreasing sulfide in sediment and promoting plant growth by plant–sediment microbial fuel cells with emerged plants

Four plant–sediment microbial fuel cells (plant-SMFCs) with four plant species, Oryza sativa, Acorus calamus, Spathiphyllum petite and Chamaedorea elegans, were built to investigate sulfide concentrations, pH and oxidation–reduction potential (ORP) in the sediment as well as plant growth. Sulfide concentrations at 1 and 2 cm depth of sediment in plant-SMFCs and their control reactors were 1.66 ± 0.30, 9.29 ± 3.46, 2.38 ± 0.10 and 24.20 ± 1.02 μmol g−1, respectively. The ORP in water and sediment of 1 and 2 cm depth in plant-SMFCs was 106.0 ± 7.7, − 142 ± 30 and − 209 ± 9 mV, respectively. The ORP in the three control reactors was 119.0 ± 11.5, − 209 ± 9 and − 386 ± 2 mV, respectively. Harvest of O. sativa, A. calamus, Spathiphyllum petite and C. elegans was 0.218 ± 0.009, 0.136 ± 0.007, 0.127 ± 0.007 and 0.340 ± 0.007 gDW g−1GW in the plant-SMFCs, while that of their control reactors was 0.179 ± 0.011, 0.127 ± 0.008, 0.102 ± 0.007 and 0.318 ± 0.006 gDW g−1GW, respectively. The results showed that sulfide concentrations decreased in sediments of plant-SMFCs, while the ORPs in both the overlying water and sediments increased. Moreover, plant growth due to operating plant-SMFCs was promoted. Running plant-SMFCs abates the toxicity of sulfide to the emerged plants as well as decreases the sulfide emission in water–plant–sediment systems.

EFFECT OF SOME POST-HARVEST TREATMENTS ON CUT LEAVES OF CHAMAEDOREA ELEGANS

This study was carried out at the Post-harvest Lab. of Ornamental Plants and Landscape Gardening Res. Dept., Hort. Res. Inst., Giza, Egypt during the two seasons of 2014/2015 and 2015/2016. The aim of this study is to investigate the effect of GA3, BA, 8-HQC, CA and Sug. as preservative solution on improving the quality of the leaves, delaying leaf wilting and leaf yellowing and extending the shelf life period of cut leaves of Chamaedorea elegans. The results showed that, the treatment of the solution containing T14: GA3 at 50 ppm + BA at 20 ppm + 8-HQC at 300 ppm + CA at 300 ppm + Sug. at 2%, followed by the solution containing the T13: GA3 at 50 ppm + BA at 20 ppm + CA at 300 ppm + Sug. at 2% significantly increased the water uptake, water balance, general appearance, vase life, concentration of chlorophyll a, b, carotenoids and total carbohydrates. It also reduced the amount of water loss in all days compared to other treatments. It can be recommended holding cut foliage of Chamaedorea elegans in solution containing GA3 at 50 ppm + BA at 20 ppm + 8-HQC at 300 ppm + CA at 300 ppm + Sug. at 2% followed by the solution containing GA3 at 50 ppm + BA at 20 ppm + CA at 300 ppm + Sug. at 2% to improve cut leaves quality and longer vase life was reached 84 days.

Towards smarter harvesting from natural palm populations by sparing the individuals that contribute most to population growth or productivity

Abstract Natural populations deliver a wide range of products that provide income for millions of people and need to be exploited sustainably. Large heterogeneity in individual performance within these exploited populations has the potential to improve population recovery after exploitation and thus help sustain yields over time. We explored the potential of using individual heterogeneity to design smarter harvest schemes, by sparing individuals that contribute most to future productivity and population growth, using the understorey palm Chamaedorea elegans as a model system. Leaves of this palm are an important non‐timber forest product and long‐term inter‐individual growth variability can be evaluated from internode lengths. We studied a population of 830 individuals, half of which was subjected to a 67% defoliation treatment for 3 years. We measured effects of defoliation on vital rates and leaf size—a trait that determines marketability. We constructed integral projection models in which vital rates depended on stem length, past growth rate and defoliation and evaluated transient population dynamics to quantify population development and leaf yield. We then simulated scenarios in which we spared individuals that were either most important for population growth or had leaves smaller than marketable size. Individuals varying in size or past growth rate responded similar to leaf harvesting in terms of growth and reproduction. By contrast, a reduction in survival chance was smaller in large individuals than in small ones. Simulations showed that harvest‐induced population decline was greatly reduced when sparing individuals from size and past growth classes that contributed most to population growth. Under this scenario, cumulative leaf harvest over 20 years was somewhat reduced, but long‐term leaf production was sustained. A threefold increase in leaf yield was generated when individuals with small leaves were spared. Synthesis and applications. This study demonstrates the potential to create smarter systems of palm leaf harvest by accounting for individual heterogeneity within exploited populations. Sparing individuals that contribute most to population growth ensured sustained leaf production over time. The concepts and methods presented here are generally applicable to exploited plant and animal species which exhibit considerable individual heterogeneity.

Phytoremediation of VOCs from indoor air by ornamental potted plants: A pilot study using a palm species under the controlled environment

Volatile organic compounds (VOCs) in indoor air have recently raised public concern due to their adverse health effects. One of hazardous VOC is Formaldehyde which can cause sensory irritation and induce nasopharyngeal cancer. The aim of this study was to investigate potted plant-soil system ability in formaldehyde removal from indoor air. We applied one of common interior plant from the palm species, Chamaedorea elegans, inside a chamber under the controlled environment. Entire plant, growing media and roots contribution in formaldehyde were evaluated by continuously introduction of different concentrations of formaldehyde into the chamber (0.66–16.4 mg m−3) each over a 48-h period. Our findings showed that the plant efficiently removed formaldehyde from polluted air by 65–100%, depending on the inlet concentrations, for a long time exposure. A maximum elimination capacity of 1.47 mg/m2. h was achieved with an inlet formaldehyde concentration of 14.6 mg m−3. The removal ratio of areal part to pot soil and roots was 2.45:1 (71%: 29%). The plants could remove more formaldehyde in light rather than dark environment. Concentrations up to 16.4 mg m−3 were not high enough to affect the plants growth. However, a trivial decrease in chlorophyll content, carotenoid and water content of the treated plants was observed compared to the control plants. Thus, the palm species tested here showed high tolerance and good potential of formaldehyde removal from interior environments. Therefore, phytoremediation of VOCs from indoor air by the ornamental potted plants is an effective method which can be economically applicable in homes and offices.

A survey on the soil pathogenic microorganisms of flowerpot in the hospital room

The purpose of this study was to examine whether the pathogenic microorganisms were detected in water and soil used as the media. After ‘Hedera helix’ and ‘Chamaedorea elegans’ which are the most used for horticultural activities were cultured in three media such as horticultural bed soil, cultural soil and tap water for 63 days, the presence of pathogenic microorganisms was examined. Pathogenic microorganisms was analyzed such as Escherichia coli O157: H7 (E. coli O157: H7) and Salmonella spp., and the method for analysis was carried out in accordance with the quality inspection on fertilizer by Rural Development Adminstration (RDA). The results of the study, pathogenic Escherichia coli O157: H7 and Salmonella spp. were not detected in the soil and water when the plants were cultivated in horticultural bed soil, cultural soil and tap water within the same conditions as the hospital environment.

Plant growth of Hedera helix and Chamaedorea elegans planted in pots in the hospital room

The purpose of this study was to investigate the changes of the growth of plants in the hospital ward depending on the types of media. After Hedera helix and Chamaedorea elegans which are the most commonly used for horticultural activities were cultured in three media such as horticultural bed soil, culture soil and tap water for 63 days, the growth status was examined. The results of the study are as follows. First, there was no significant difference in the plant height, leaf number and chlorophyll content of H. helix among three media. However, there was a significant difference in chlorophyll content of C. elegans as follows: Horticultural bed soil (SPAD=-0.2), culture soil (SPAD=-7.9) and tap water (SPAD=-14.7). There was no difference in the plant height among three media. Second, the changes of growth status between soil (horticultural bed soil and culture soil) and water (tap water) were compared. As a result, there was a significant difference in the height of H. helix (P=0.24). There was a significant difference in the chlorophyll concentration of C. elegans (P=0.24). Third, fresh weight and dry weight of plants growing in each medium were compared. The T/R ratio of fresh weight (9.51%) and dry weight (7.00%) of H. helix growing in horticultural soil was the highest. The T/R ratio of fresh weight (9.15%) and dry weight (9.00%) of C. elegans growing in tap water was the highest. According to the results of the investigation on the growth status of plants, there was no significant difference in the growth of H. helix depending on the media. However, it would be good for C. elegans to grow in soil rather than in tap water.

Survey of Plants and Types of Horticultural Therapy Program in Hospitals - Focused on the Thesis from 1998 to 2016 -

As a result of inquiring into the analysis consequent on a symptom by research subject, it was found that there were 1 paper (1.5%) which did research for the purpose of rehabilitation of the general public, 26 papers (38.8%) targeting diagnosis-related groups (DRG), and 40 papers (59.7%) targeting social consideration subject. Also, as a result of the inquiry about the frequency & number of times of horticultural therapy program implementation, it was found that 49 papers (73.1%) implemented one time a week, and 45 papers (67.2%) were surveyed as the highest by conducting a total of 11~20 sessions of horticultural therapy programs, In the analysis of horticultural therapy activities by type, plant cultivation activity was found to be the most 506 times, accounting for 41.5%, followed by 297 time crafts activity (24.4%), 213 time floral decoration activity (17.5%), and 203time others activities (16.7%). In cultivation activity, soil-using cultivation activity (25.1%) was found to be lower than the proportion (74.9%) of soiless cultivation (16.4%), crafts activity (24.4%), floral decoration activity (17.5%) and other activities (16.7%). The most used plants in a restricted place like a hospital were found to be in the order of Hedera helix, Chamaedorea elegans, Succulent plant, Syngonium podophyllum, Neofinetia falcata HU, Hoya carnosa (L.f.) R.Br.), Rosmarinus officinalis, and Spathiphyllum spp.

Removal of Low-Molecular Weight Aldehydes by Selected Houseplants under Different Light Intensities and CO2 Concentrations

The removal of five low-molecular weight aldehydes by two houseplants (Schefflera octophylla (Lour.) Harms and Chamaedorea elegans) were investigated in a laboratory simulation environment with short-term exposure to different low light intensities and CO2 concentrations. Under normal circumstances, the C1–C5 aldehyde removal rates of Schefflera octophylla (Lour.) Harms and Chamaedorea elegans (Lour.) Harms ranged from 0.311 μmol/m2/h for valeraldehyde to 0.677 μmol/m2/h for formaldehyde, and 0.526 μmol/m2/h for propionaldehyde to 1.440 μmol/m2/h for formaldehyde, respectively. However, when the light intensities varied from 0 to 600 lx, a significant correlation between the aldehyde removal rate and the light intensity was found. Moreover, the CO2 experiments showed that the total aldehyde removal rates of Schefflera octophylla (Lour.) Harms and Chamaedorea elegans (Lour.) Harms decreased 32.0% and 43.2%, respectively, with increasing CO2 concentrations from 350 ppmv to 1400 ppmv. This might be explained by the fact that the excessive CO2 concentration decreased the stomatal conductance which limited the carbonyl uptake from the stomata.

Posibilidades financieras de diversificación en cafetales mexicanos

Por muchos años el cultivo del café ha sido un uso altamente socorrido para tierras de vocación forestal en zonas de bosque mesófilo de montaña. En este sentido es pertinente explorar las cualidades que puedan tener las variantes del cultivo que conducen hacia un paisaje y estructuras más cercanas a la del bosque natural, tal como el caso del empleo de cultivos asociados, sea como sombra o como de cobertura. La introducción de palma camedor (Chamaedorea elegans) y de la nuez de macadamia (Macadamia spp), dentro de cafetales es una estrategia iniciada por los mismos cafeticultores. En ella, simultáneamente se aporta diversidad, tanto en un aspecto biológico, como en el sentido de enfrentar los riesgos de un mercado internacional violentamente fluctuante, característico de este grano. Análisis financieros que comparan estas dos formas de cultivo con formas intensivas donde el café es el único producto, como el café con sombra de especies forestales, el café a pleno sol, y café orgánico, hacen ver que estas opciones son económicamente viables pero financieramente inferiores al café a sol, dado el actual escenario económico, justificándose el policultivo sólo para empresarios para los que los riesgos de mercados cafetaleros adversos sean inaceptables. Macadamia aparece como una inversión lo suficientemente fuerte en sí misma como para sugerir que se le desarrolle en monocultivo. La comparación asume mercados libres y establece condiciones de comparación de equidad que obligan a usar valores reales para insumos y productos, vigentes en México en la primavera de 1995, y un costo de capital privado real estimado en 5%. Los datos biológicos principales, como el rendimiento, provienen de evidencias empíricas, la mayoría mexicanas.

Effect of Removing Indoor HCHO by Several Korean Foliage Plants

The objective of this study is to study the air cleaning ability of indoor plants and to find easier ways of its application. Carbon dioxide, the index of gas pollutant and formaldehyde, found in almost every indoor equipment were chosen to implement the air cleaning experiments. Selected plants in this study were 6 types; Ficus benjamina, Epipremnum aureum, Chamaedorea elegans, Fatsia japonica, Spathiphyllum spp. and Hedera helix. Measuring photosynthesis and breathing volume of each plant for 24 hours, total volume of carbon dioxide reduction for each plant was calculated; Ficus benjamina 49ppm, Epipremnum aureum 99ppm, Chamaedorea elegans 34ppm, Fatsia japonica 123ppm, Spathiphyllum spp. 115ppm, and Hedera helix 42ppm (leaf area unit: 1000Cm2). The time frame, in which the maximum instantaneous consumption of carbon dioxide was shown, was different for each plant; in most cases, the highest absorption rate of carbon dioxide was seen in 0.67~1.54 mW/Cm3 of light quantity. Injecting low concentration formaldehyde (250ppb) and comparing control group in darkened chamber, total volume of formaldehyde reduction for each plant was calculated; Ficus benjamina 128.6ppb, Epipremnum aureum 152ppb, Chamaedorea elegans 127.8ppb, Fatsia japonica 165.9ppb, Spathiphyllum spp. 156ppb, Hedera helix 115ppb (leaf area unit: 1000Cm2). Using statistical program SPSS 7.0, correlation analysis regarding instantaneous consumption volume of carbon dioxide and formaldehyde for each plant was implemented. Thanks to the conversion formula stated below, concentration of formaldehyde in indoor air and purification power of each plant were easily calculated. For 250ppb of formaldehyde, Y(HCHO consumption rate of all plants, ppb) = 0.387X (CO2 consumption rate of all plants, ppm) + 0.758. It was confirmed that plants can reduce indoor air pollutant from the simple fact; plants must absorb gas pollutants in the process of photosynthesis. Although it takes longer time to eliminate indoor air pollutants than mechanical air cleaners, it is the most environment-friendly method; less costs, continuous air purification and making no secondary pollutants.

Strong persistent growth differences govern individual performance and population dynamics in a tropical forest understorey palm

Summary Persistent variation in growth rate between individual plants can have strong effects on population dynamics as fast growers reach the reproductive size at an earlier age and thus potentially contribute more to population growth than slow growers. In tropical forests, such persistent growth differences have so far been documented for canopy tree species, where they are primarily associated with forest gap dynamics, but not for forest understorey species which are less responsive to gaps. Here, we study persistent growth differences and their demographic consequences for a tropical forest understorey palm, Chamaedorea elegans. We measured internodes along stems and annual leaf production rates to reconstruct lifetime growth trajectories. Using regression analysis, we determined the relative effect of stem length and past growth rate on vital rates (survival, growth and reproduction). We then simulated population dynamics using integral projection models (IPMs), in which individuals were categorized by both stem length and lifetime past growth rate. Stem growth differences among individual palms persisted over most of their lifetime. Past growth rate averaged over the palm's lifetime proved to be a very good predictor of growth, reproduction probability and seed production, often much better than stem length or age. The effects of past growth rate were positive, indicating that fast growers maintain high rates of growth and reproduction. Projected population growth rate (λ) was 1.056, and stable stage distributions closely resembled observed population structures. Separating individuals with above‐median and below‐median past growth rates in IPMs revealed substantial differences in elasticity values. The 50% fastest growers had a 1.8 times higher elasticity, and thus a 1.8 times higher contribution to population growth, compared to slow growers. Synthesis. Strong and persistent growth differences that are probably associated with environmental (edaphic) and/or genetic factors govern individual performance and population dynamics of a tropical forest understorey palm. Overall, our study shows that strong inter‐individual growth variation is not limited to canopy trees and that it can be generated by other factors than canopy dynamics. It is likely that persistently fast‐growing ‘super performers’ govern population growth of many long‐lived species.