Plant Tissue Analysis Research Articles

Tree Species of Wet Tropical Forests Differ in Their Tissue Biochemistry and Effects on Soil Carbon Dynamics

Given the hypothesized effects on soil organic matter (SOM) of polyphenols in plant tissues, differences among tree species in their biochemical composition could influence the turnover and accrual of SOM in various ways. The extent to which the biochemical composition of leaf and fine-root tissues differ among tropical tree species, and the effects on soil dynamics, are largely undocumented, however. We used cupric oxide analyses of plant tissues and soil in long-term, replicated, mono-dominant 15-year-old plantations at La Selva Biological Station, Costa Rica, to test for differences among six tree species. We related these results to companion studies in this experimental site to evaluate relationships between interspecific differences in tissue biochemistry and SOM dynamics. Newly senesced leaves and fine roots of the six species differed in their concentrations of three lignin-derived families of phenols, the cinnamyls, syringyls and vanillyls (p < 0.0001 for all tests). Cinnamyl and syringyl phenols in soil differed significantly among species (p = 0.0408, 0.0071, respectively), whereas vanillyl phenols did not (p = 0.83). The degree of decomposition of syringyl and vanillyl phenols in soil also differed (p = 0.0015, 0.0027, respectively), as evidenced by the ratio of carboxylic acid to aldehyde compounds, based on the concept that carboxylic acids are a common by-product of oxidative decomposition of lignin by microorganisms. In our study in a single site, i.e., the same soil type, climate, and growth form of vegetation, total phenols in soil ranged from 5 to 21 mg g–1 organic carbon (OC) across the 20 plots, and the endpoints were both broad-leaved evergreen species; even the means across species, 7–12 mg g–1 OC, covered half the range of values reported in another study across a broad latitudinal range of sites. This study’s tree species differed in traits that influenced at least four factors that explained their differential effects on soil organic carbon (SOC) pools: (1) Fine-root detrital inputs; (2) Fine-root syringyl concentrations; (3) Soil pH; and (4) Macroaggregate structure. This trait-based approach provides a process-based understanding of how trees species influence SOC dynamics, and the consequences for ecosystem properties, under land-use change that involves shifts in species composition.

Plant Tissue Testing: How Precise Is My Lab Data?

The carpenter’s adage of “measure twice and cut once” is an important one in most things we do. But how precise is the tape measure capable of providing that information? In plant tissue analysis, we need to have an understanding of what is realistic with regard to the precision provided by laboratories and not attempt to interpret the results to a finer scale than what is actually achieved. Agricultural and environmental laboratories doing plant analysis are capable of great precision. However, some methods have good precision, and others are relatively less precise. Earn 0.5 CEUs in Crop Management by reading the article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/981.

Assessment of genetic diversity of Turkish maize landraces for phytic acid and total phenolic contents

Assessment of genetic diversity of Turkish maize landraces for phytic acid and total phenolic contents

Nutrient stock in the forest component in a crop-livestock-forest integration system in Central Brazil

Integrated systems are sustainable alternatives, where agricultural, forestry, and/or livestock components occupy a given area through consortium, rotation, or succession. Considering this importance, this work had as objective to quantify the stock of above-ground biomass (wood, leaves, bark, and branches) of 6 years Eucalyptus urograndis in a crop-livestock-forest integration system (CLFS). It also involved calculation of the nutrient utilization in biomass conversion through the Biological Utilization Coefficient (BUC) and design of different export scenarios of these nutrients through the harvest in order to calculate the reduction in the demand for inputs. Nutrient stock was determined from the biomass sampled in the field and from the plant tissue analysis. It is verified that the highest concentrations of macronutrients are present in wood component, except for Ca. The concentration gradient of micronutrients was: Leaves> Fe> Mn> B> Cu> Zn; Branches and Bark: Fe> Mn > B> Zn> Cu; and wood: Mn > Fe > Zn > Cu > B. Considering BUC conversion rate decline, it presented the following order: S> P> Mg> Ca> N> K for macronutrients and B> Cu> Zn> Fe> Mn for micronutrients. The most appropriate export scenario was to harvest only timber component to minimize the nutritional export. The nutritional dynamics within the eucalyptus are altered according to the diametric structure of the trees. The nutritional elements are concentrated in different compartments according to the availability and need of the plants.

Molecular identification of timber species from sawn timber and roundwood

Illegal and unsustainable logging of forests have contributed to deforestation and a massive loss of biodiversity, and despite the efforts to regulate the trade of plants and combat the commercialization of illegal logging, the problem continues. DNA analysis of plant tissues is an effective method in species identification, and it is important to dedicate efforts to obtain and amplify DNA from dry wood or exposed to a sawmill process in which its origin is not clear. The aim of this research was to present a strategy to identify tree species from sawn timber and roundwood, based on the use of molecular identification tools. Wood samples of standing trees of Pinus pseudostrobus (PFCap1), round core samples (Ro) and plank wood (SaT) of Pinus pseudostrobus and Pinus devoniana were used. All the samples underwent a DNA extraction protocol, amplification, sequencing, and analysis in the NCBI database. The results showed an efficient extraction of the genetic material, revealing high purity ratios ​​for the three sample groups (PFCap1, Ro and SaT) and quantitative data of the amplified DNA. The information obtained through sequencing showed identities of up to 100% homology (NCBI database). We can conclude that the standardized method developed was successful using the trnL and trnLF primers, managing to isolate, amplify, and sequence the DNA from sawn timber and roundwood, and to identify the age of the tree and the time elapsed between the felling of the tree and the sampling, which are directly related to the success of this method.

Animal Manure, Neem Cake, Biochar, Vermicompost or Urea: Choosing the Better Option for <i>Spinacia oleracea</i> Growth and Soil Fertility

Production of safe food through organic farming while maintaining soil sustainability is the crucial challenge of recent time. As such a pot experiment was conducted using animal manure (TAM), neem-cake (TNC), vermicompost (TVC), biochar (TBC) and urea (TU) with control (TC) to assess their capacity to stimulate Spinacia oleracea growth under field condition and their impact on soil fertility. Six treatments: TC, TAM, TNC, TVC, TBC, TU with three replications were used in completely randomized design (CRD). All the plant growth parameters were measured at regular interval up to maturity. Complete chemical analysis of plant tissue, amendments and soil was carried out. Nitrogen use efficiency (NUE) under different treatments was calculated at 45 and 60 days. All the treatments showed statistically significant (P i.e., plant height with P (R = 0.887); leaf area with N (R = 0.957) and P (R = 0.985); dry weight with N (R = 0.996), P (R = 0.994) and K (R = 0.860). Significant (P < 0.001) increase in post-harvest soil C and CEC content was found with all the treatments. The highest availability of N, P and S was observed under treatment TNC. For short duration crop like spinach, TNC is the best option followed by TVC as they release nutrient quickly than TBC and TAM.

Assessment of Soil Chemical Properties and Coffee Leaf Analysis in Goma Woreda of Oromia Region

Information on soil test and plant analysis is essential for sustainable soil fertility management and crop production. Conversely, this is lacking for smallholder coffee farms in Gomma district, Southwestern Ethiopia. Thus, the objectives of this study were to assess and determine the nutritional status of the soil–plant relation from coffee growing farms in Gomma district. Accordingly, soil samples, coffee leaves and field history were collected from 10 coffee farms during pinhead phase. Soil samples collected from 0-30 cm depth were prepared and analyzed in the laboratory following standard procedures. For data analysis, descriptive statistics was used. Results showed that the soil pH ranged from strongly to moderately acidic (pH 4.72–5.75) and low to medium in their organic matter (2.68–4.72%) content. Total N content was low in 20% of the samples, while 100% of the soil samples found to be deficient in P content. Exchangeable Ca ranged from low to high, exchangeable Mg in all soil samples was medium, while exchangeable K ranged medium to very high. Nevertheless, K to Mg ratio varied from 0.64:1 to 2.62:1, indicating Mg induced K deficiency in 10%. The plant tissue analysis depicted that 50, 60 and 50% low in N, P and K, respectively, while high in Ca and Mg concentrations. Significant and positive correlations of soil phosphorus, potassium, calcium and magnesium with tissue concentration were existed. For sound conclusion, soil test and crop response calibration, appropriate soil, N, P, K, organic fertilizers and lime are recommended for future work.

Phytonanoremediation by Avicennia Germinans (black mangrove) and Nano Zero Valent Iron for Heavy Metal Uptake from Cienaga Las Cucharillas Wetland Soils

Plants may be used to remove or convert pollutants into harmless products by bioaccumulating, degrading, extracting, or immobilizing them. Phytoremediation processes offer advantages over traditional remediation methods such as chemical oxidation, excavation, and thermal treatments. A combined usage of mangroves and nano zero valent iron (nZVI), could be implemented for the remediation of Cadmium (Cd), Lead (Pb) and Arsenic (As) in contaminated wetlands. Here, a phytonanoremediation process which combined A. germinans and nZVI was evaluated for a period of 5 months using contaminated soil from Cienaga las Cucharillas, Cataño, Puerto Rico. We evaluate the efficiency of the phytonanoremediation process using 15 individuals of A. germinans with and without nZVI to remove Cd, Pb and As in contaminated soil by inductively coupled plasma (ICP) analysis measurements. A plant tissue analysis of root, stem and leave of A. germinans after nZVI exposure in their corresponding soil was conducted using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) techniques. Bioaccumulation factors (BAF) and Translocation factors (TF) were calculated. A BAF < 1 combined with a TF < 1 indicates that A. germinans is not working as a hyperaccumulator plant, but rather as excluders for Cd and Pb metals. Data obtained in the nanoenvironmental project suggested that the interaction of nZVI with A. germinans is an efficient way to enhance the bioavailability of Pb2+ and Cd2+ and enable plants to better translocate them into their aerial parts.

Recent developments of MALDI MSI application in plant tissues analysis.

Mass spectrometry imaging (MSI) combined with matrix-assisted laser desorption/ionization (MALDI) is an efficient technology applied in plant metabolomics research. This technique allows for visualization of spatial distribution of metabolites such as: lipids, proteins, peptides and DNA sequences, by determining the x, y coordinates of the compounds exactly in plant tissue. Simplicity of the tissue preparation without the need of prior exact knowledge about the analytes is a great advantage of this method. In this review, we provide an overview of experimental workflow including sample preparation, data acquisition and analysis, methodology, and some recent applications of MALDI MS imaging in plant metabolomics research.

Recent Progress on Tissue Analysis by Mass Spectrometry without Sample Pretreatment

Abstract Tissue samples are widely used for the study of metabolomics, lipidomics and proteomics due to their abundant useful biomolecular information. Modern analytical mass spectrometry has the ability to directly obtain the molecular information contained in various tissue samples (e.g., plant tissues, animal tissues, and clinical tissues, etc.) in real-time, with minimal or no sample pretreatment. Such features of analytical mass spectrometry promote the throughput of tissue analysis and extend the application of tissue analysis in multiple fields. This review summarizes the applications of mass spectrometry in direct analysis of plant tissues, animal tissues and clinical tissues, and the challenges and perspectives of mass spectrometry in direct analysis of tissue samples are discussed as well.

Use of Fluorescence Sensing to Detect Nitrogen and Potassium Variability in Maize

Real-time fluoro-sensing is a promising crop sensing technology to support variable-rate nutrient management for precision agricultural practices. The objective of this study was to evaluate the potential of fluoro-sensing to detect the variability of nitrogen (N) and potassium (K) in the crop canopy at the early growth stages of maize (before the V6 crop growth stage). This study was conducted under greenhouse conditions in pots filled with silica sand, and maize plants were supplied with modified Hoagland’s solution with different rates of N and K. Sensor readings were collected using a Multiplex®3 fluorescence sensor and analyzed using ANOVA (analysis of variance) to test differences in crop response to nutrient rates. Regression analysis was used to assess the ability of fluorescence sensor-based indices to estimate N and K in the crop canopy. The results of this study indicate that all fluorescence indices under consideration enabled the detection of N variability in the maize canopy prior to the V2 crop growth stage. The NBI_B (nitrogen balance index blue) index enabled N uptake detection (R2 = 0.99) as early as the V2 crop growth stage. However, the fluorescence indices failed to identify K deficiency, as the maize plants with K treatments showed little to no variability of this nutrient at early crop growth stages as measured by plant tissue analysis. The results present a tremendous opportunity to assess N uptake at early growth stages of maize for precision nitrogen application. We recommend using fluorescence sensor-based NBI_B or NBI_R (Nitrogen balance index red) for early detection of nitrogen uptake in maize for precision nitrogen management.

Growth and elemental uptake of Rhodes grass (Chloris gayana) grown in a mine waste-contaminated soil amended with fly ash-enriched vermicompost.

Vegetation cover in mine waste-affected soils is necessary to ensure sustainability of these fragile ecosystems. This study evaluated the potential of fly ash-enriched vermicompost (FV) to improve growth of Chloris gayana in a gold mine waste-affected soil. The treatments in the study were based on optimizing phosphorus supplied as vermicompost at 20mg P and 40mg P per kilogram soil which were compared to triple super phosphate (TSP) applied at 40mg P/kg. The 40-mg P/kg FV treatment resulted in 38.4%, 164% and 182.5% significant increase in shoot height, shoot biomass and root biomass, respectively, relative to the control. The increased biomass was reflected in the plant tissue analysis where 40mg P/kg FV had high P, Ca, Mg and K, though not significantly different to the 20-mg P/kg FV treatment. Amendment effect had no influence on plant tissue N, Pb, Cd and As. Chloris gayana uptake of Fe, Mn, Zn and Cr was significantly reduced with addition of the vermicompost, whereas Cu and B were significantly increased in the 40-mg P/kg FV treatment relative to the control though the increases did not exceed the critical concentration limits of these elements. Therefore, re-vegetation of mine waste-contaminated soils can be achieved with addition of FV at a rate of 40mg P/kg FV. However, more studies may need to be done under field conditions to further evaluate the effectiveness of such vermicomposts in improving the re-vegetation capacity of mine waste-contaminated soils.

Towards single-cell ionomics: a novel micro-scaled method for multi-element analysis of nanogram-sized biological samples

BackgroundTo understand processes regulating nutrient homeostasis at the single-cell level there is a need for new methods that allow multi-element profiling of biological samples ultimately only available as isolated tissues or cells, typically in nanogram-sized samples. Apart from tissue isolation, the main challenges for such analyses are to obtain a complete and homogeneous digestion of each sample, to keep sample dilution at a minimum and to produce accurate and reproducible results. In particular, determining the weight of small samples becomes increasingly challenging when the sample amount decreases.ResultsWe developed a novel method for sampling, digestion and multi-element analysis of nanogram-sized plant tissue, along with strategies to quantify element concentrations in samples too small to be weighed. The method is based on tissue isolation by laser capture microdissection (LCM), followed by pressurized micro-digestion and ICP-MS analysis, the latter utilizing a stable µL min−1 sample aspiration system. The method allowed for isolation, digestion and analysis of micro-dissected tissues from barley roots with an estimated sample weight of only ~ 400 ng. In the collection and analysis steps, a number of contamination sources were identified. Following elimination of these sources, several elements, including magnesium (Mg), phosphorus (P), potassium (K) and manganese (Mn), could be quantified. By measuring the exact area and thickness of each of the micro-dissected tissues, their volume was calculated. Combined with an estimated sample density, the sample weights could subsequently be calculated and the fact that these samples were too small to be weighed could thereby be circumvented. The method was further documented by analysis of Arabidopsis seeds (~ 20 µg) as well as tissue fractions of such seeds (~ 10 µg).ConclusionsThe presented method enables collection and multi-element analysis of small-sized biological samples, ranging down to the nanogram level. As such, the method paves the road for single cell and tissue-specific quantitative ionomics, which allow for future transcriptional, proteomic and metabolomic data to be correlated with ionomic profiles. Such analyses will deepen our understanding of how the elemental composition of plants is regulated, e.g. by transporter proteins and physical barriers (i.e. the Casparian strip and suberin lamellae in the root endodermis).

Induced Self-aspiration Electrospray Ionization Mass Spectrometry for Flexible Sampling and Analysis.

Electrospray ionization (ESI) operating in pulse mode can enhance the utilization efficiency of the electrospray ions by a mass spectrometer. Herein, a novel ionization technique called induced self-aspiration-electrospray ionization (ISA-ESI) was developed based on self-aspiration sampling and capacitive induction. The sample solution polarized in a strong electric field was pulsed drawn into a capillary that was connected to a subambient chamber. The sample solution with polarized ions forms a charged liquid column, which can initiate an electrospray when reaching the capillary outlet. In addition to the self-aspiration ability, the use of a constant high voltage supply and no electrical contact with the solution can also simplify the sampling and ionization operation, enabling a convenient ESI mass spectrometry analysis. The developed ISA-ESI source has been used for multidimensional monitoring of chemical reactions as well as liquid extraction surface analysis of plant tissues. It was expected that this special ionization method could be extended to automated high-throughput ESI-MS analysis.

Plant tissue analysis as a tool for predicting fertiliser needs for low cyanogenic glucoside levels in cassava roots: An assessment of its possible use.

The use of plant tissue analysis as a tool for attaining low cyanogenic glucoside levels in cassava roots, has hardly been investigated. Just as the quality of crops is improved through the use of plant tissue analysis, the same can probably be done to consistently attain the lowest possible cyanogenic glucoside levels in cassava roots. High levels of cyanogenic glucosides in consumed fresh cassava roots or in their products have the potential of causing cyanide intoxication, hence the need to lower them. An experiment was thus conducted to assess the occurrence of meaningful relationships between plant nutritional status and cyanogenic glucoside production in cassava roots. Total hydrogen cyanide (HCN) levels in cassava roots were used to assess cyanogenic glucoside production. Using NPK fertiliser application to induce changes in plant nutritional status, the main objective of the study was investigated using the following sub-objectives; (1) to determine the effects of increased NPK fertiliser application on cassava root HCN levels; (2) and to show the occurrence of relationships between changes in nutrient levels in plant 'indicator tissue' and HCN levels in cassava roots. The study was a field experiment laid out as a split-plot in a randomized complete block design with three replicates. It was repeated in two consecutive years, with soil nutrient deficiencies only being corrected in the second year. The varieties Salanga, Kalinda, Supa and Kiroba were used in the experiment, while the NPK fertiliser treatments included; a control with no fertiliser applied; a moderate NPK treatment (50 kg N + 10 kg P + 50 kg K /ha); and a high NPK treatment (100 kg N + 25 kg P + 100 kg K /ha). A potassium only treatment (50 kg K/ha) was also included, but mainly for comparison. The root HCN levels of Salanga, Kalinda and Kiroba were significantly influenced by NPK fertiliser application in at least one of the two field experiments, while those of Supa remained uninfluenced. Changes in plant nutritional status in response to fertiliser application were thus shown to influence cyanogenic glucoside production. The results of the multiple linear regression analysis for the first field experiment, generally showed that the root HCN levels of some cassava varieties could have been 'reduced' by decreasing concentrations of nitrogen, potassium and magnesium in plants, or by improving plant calcium concentrations along with NPK fertiliser application. However, in the second field experiment (with corrected soil nutrient deficiencies) the regression analysis generally showed that the root HCN levels of some cassava varieties could have been 'reduced' by improving either one or a combination of the nutrients phosphorous, zinc and potassium in plants along with NPK fertiliser application. Although the results obtained in the two experiments had been contradicting due to slight differences in how they were conducted, the study had nonetheless demonstrated the occurrence of meaningful relationships between plant nutritional status and cyanogenic glucoside production; confirming the possible use of plant tissue analysis in predicting fertiliser needs for the consistent attainment of low cyanogenic glucosides in cassava roots.

A rapid and effective optical-clearing technique for deep tissue fluorescence imaging in trees

This non-invasive clearing technique allows for deep clear imaging of plant tissue and 3D structural analysis of leaf cells. Optical-clearing technology allows the reduction of light scattering and absorption in internal biological tissues. This technology allows microscopy techniques, such as confocal laser scanning microscopy, to obtain structural information deep within the internal tissue and also allows for three-dimensional (3D) tissue analysis. However, the transparent method in plants remains to be further elucidated. In this study, we first report on a non-invasive, rapid and effective clearing technique that increases the transmission of light through plants. Importantly, we found that the leaf terminal veins of four species had different characteristics based on fluorescence imaging observations. Moreover, through the combination of transparent technology and microscopic observation, we clearly observed the three-dimensional structure of plant leaf cells. Our simple and rapid clearing method is useful for fluorescence imaging the intact internal structure. Taken together, the results of this study will provide valuable information for further microscopic experimental investigations in trees.

How fully productive olive trees (Olea europaea L., cv. 'Chondrolia Chalkidikis') manage to over-satisfy their P nutritional needs under low Olsen P availability in soils?

Often, from soil and plant tissue analyses, over-sufficient foliar P levels in olive trees, grown under low Olsen P availability, are determined. In order to deepen our knowledge in this topic, a field P fertilization experiment (with or without supply of the fertilizer 0-46-0) with 25-year-old olive trees was conducted, in order to investigate if: i) soil organic P was a sufficient 'pool' to satisfy the P nutritional needs of mature, fully productive, olive trees under low Olsen P availability and sufficient organic matter content, ii) the activities of acid and alkaline phosphatase were enhanced under low Olsen P availability, iii) soil chemical properties were significantly influenced by P fertilization, iv) significant differences in foliar nutrition of olive trees existed between P-fertilized (+P) and unfertilized (-P) trees. Our results indicated that in the -P plots 48 % of the total soil P was in organic fraction, while in the + P ones approximately 23 % of the total P was in organic form. In contrast, Olsen, inorganic and total P fractions were significantly higher in the + P plots. In addition, in the + P plots significantly lower: i) soil Fe, Mn and Zn, and ii) foliar Ca, Mg and Mn concentrations were determined, while, in contrast, iii) higher leaf K concentration was found. Foliar P was not influenced by P fertilization, while at the same time, both the activities of alkaline and acid phosphatase were significantly higher in the –P plots, compared to those received P fertilization. Overall, the kind of management of olive groves (sufficient organic matter levels, with or without inorganic P fertilization inputs) significantly influences P dynamics and modifies its fractions in soils, while it also affects organic P mineralization and supports P nutrition for olive trees. It is believed that these data reveal the crucial role of organic matter to sustain P uptake and contribute towards a sustainable management of olive groves to support and sufficiently satisfy the P nutritional needs of olive trees, by also significantly reducing the unnecessary annual P fertilizer inputs.

Temporal variation in positive and negative interactions between marsh herbivores mediated by changes in plant traits

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 634:89-97 (2020) - DOI: https://doi.org/10.3354/meps13187 Temporal variation in positive and negative interactions between marsh herbivores mediated by changes in plant traits Alejandro D. Canepuccia1,*, Daniela Alemany1, Esteban Espinosa Vidal2, M. Fernanda Alvarez3, Oscar O. Iribarne1 1Laboratorio de Ecología, Instituto De Investigaciones Marinas y Costeras (IIMYC), FCEYN, UNMDP-CONICET, CC1260, 7600 Mar del Plata, Argentina 2Center for Strategic Technologies of the Northeastern Region (CETENE), Cidade Universitária, Recife 50740-545, Pernambuco State, Brazil 3Instituto de Limnología ‘Raúl A. Ringuelet’ (ILPLA, CONICET), Universidad Nacional de La Plata, 1900 La Plata, Argentina *Corresponding author: acanepuc@mdp.edu.ar ABSTRACT: Studies on bidirectional benefactor-beneficiary interactions between organisms have generally neglected the importance of this feedback in trophic levels other than plants. The burrowing crab Neohelice granulata aids the development of larvae of the stem-boring moth Haimbachia sp. nov. within the stems of Spartina alterniflora. In our research, we evaluated whether the stem-boring moth subsequently influences crab feeding on these marsh plants. Surveys and experiments in a tidal marsh of the SW Atlantic coast (36°22’S) showed that at the beginning of the stem-boring moth attack there was no difference in crab herbivory between plants with or without larvae of the stem-boring moth. However, after 3.5 mo, crabs foraged more on plants without larvae than on those with larvae. Plant tissue analyses showed a decrease in leaf tissue carbon concentrations in plants with larvae. This change in the nutritional quality of leaves, caused by construction of the stem-boring moth galleries, could explain the segregation in plant use between both herbivores. Unlike an allelochemical response, the non-specificity of the induced nutritional change could impair a wide variety of herbivores regardless of their feeding modes or taxonomic proximity. These effects could propagate bottom-up through the food-web, leading to more diffuse interspecific effects. Thus, here we show how the benefactor-beneficiary feedback between herbivores can be important for the maintenance of species coexistence and the functioning of communities. KEY WORDS: Positive-negative interactions · Indirect interactions · Benefactor-beneficiary relationship · Facilitation · Herbivory · Plant-mediated interactions · Salt marsh · Crabs · Stem-boring moth Full text in pdf format PreviousNextCite this article as: Canepuccia AD, Alemany D, Espinosa Vidal E, Alvarez MF, Iribarne OO (2020) Temporal variation in positive and negative interactions between marsh herbivores mediated by changes in plant traits. Mar Ecol Prog Ser 634:89-97. https://doi.org/10.3354/meps13187 Export citation Mail this link - Contents Mailing Lists - RSS Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 634. Online publication date: January 23, 2020 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2020 Inter-Research.

Plant responses to nutrient addition and predictive ability of vegetation N:P ratio in an austral fen

Abstract Previous studies of the N:P ratio in wetland plants have been carried out in northern hemisphere wetlands where atmospheric nitrogen deposition is higher. There is little research on foliar N:P ratio as a potential indicator of nutrient limitation in vegetation communities in southern hemisphere wetlands. This study aimed to redress this knowledge gap and answer the following questions: how well does the plant tissue nitrogen to phosphorus (N:P) ratio predict wetland plant community nutrient limitation, as indicated by vegetation standing stocks and below‐ground biomass, in southern hemisphere fens? Secondly, what are the impacts of realistic upper levels of farm nutrient run‐off on natural montane fen vegetation? Low (35 kg ha−1 year−1) and high (70 kg ha−1 year−1) levels of nitrate‐N or ammonium‐N with and without P (20 kg ha−1 year−1) were added to 81 vegetation plots over a period of 2.75 years. Species composition, plant nutrient status, and above‐ground live vegetation standing stocks were assessed after 3 years, and below‐ground biomass after 2 years. Plant tissue analysis suggested the community was N limited or N and P co‐limited; we found greater standing stocks of vegetation in plots treated with 70 kg ha−1 year−1 ammonium‐N, indicating N limitation. No difference between other treatments was found in above‐ground standing stocks or below‐ground biomass. Plant species cover increased in both high N treatments, consistent with N limitation. These changes in plant species cover were accompanied by significant decreases in species richness in both high N treatments. Native species dominated the vegetation and this was unaffected by nutrient addition (90% cover). This is one of the first studies to test and find support for the N:P ratio in southern hemisphere wetlands. Observed declines in species richness after N fertilisation in an N‐limited fen suggests increased N may pose risks to austral wetlands. Responses by plant communities (changes in composition, biomass) to lower levels of nutrient addition may require longer periods of fertilisation to be apparent in slow growing ecosystems.

Methods for Nutrient Diagnosis of Fruit Trees Early in the Growing Season by Using Simultaneous Multi-element Analysis

Fruit tree nutrition is one of the most important factors in terms of growth and productivity. Measurement of nutritional requirements is an important aspect of nutrient management because nutritional disorders reduce yield and fruit quality. This review explores how nutrient imbalances affect the yield and fruit quality of fruit trees, and presents methods for diagnosing fruit tree nutritional disorders in order to correct nutritional deficiencies. In orchards, differences between soil sampling sites and locations of fruit tree roots when the root system is deep and unevenly distributed make it difficult to obtain representative soil samples from which to measure the forms of nutrients available to the trees. The delayed response of fruit trees to fertilizer applications compared with annual crops makes it difficult to determine their nutritional status through soil analysis immediately after application. In addition to soil analysis, plant tissue analysis is used to determine nutritional status and fruit tree nutritional requirements. In particular, earlier analysis in the growing season could allow sufficient time to correct any deficiencies before harvest. A recent approach that relies on analysis of the ionome, which is defined as the entire mineral nutrient and trace element complement in an organism, through simultaneous quantitative measurement enables comprehensive evaluation of multi-element composition. This approach could be especially effective as major decreases in yield and fruit quality are often caused by the interaction of several elements. Until recently, studies of fruit tree nutritional disorders have focused on particular nutrients, not multiple elements. Therefore, the application of ionomic analysis is a promising approach to elucidate multi-element interactions for accurate diagnosis of nutritional disorders.