A simple method to assess macrofungal sporocarp biomass for investigating ecological change

2007 ◽  
Vol 85 (7) ◽  
pp. 652-658 ◽  
Author(s):  
B.B. Tóth ◽  
A. Feest
Keyword(s):  
Environmental Changes ◽  
Fine Root ◽  
Dry Mass ◽  
Accurate Estimation ◽  
Ecological Change ◽  
Fruiting Bodies ◽  
Ectomycorrhizal Community ◽  
Simple Method ◽  
Area Index ◽  
Forested Areas

The methodologies used for studying macrofungal communities are an eclectic assemblage of many different and unstandardized approaches. In this study we propose a simple, nondestructive but still informative method to assess fungal sporocarp biomass in forested areas. We use the number of fruiting bodies found in the surveyed plot, and data on cap diameter of the species from the literature to calculate a cap area index. We show that this index very strongly correlates with the measured total dry mass of the species obtained from the same plot. We point out that the cap area index provides a more accurate estimation of the epigeous fungal sporocarp biomass than do the species sporocarp numbers. This new methodology allows the spatiotemporal distribution of a fungal community in an ecosystem to be followed. Since sporocarp production responds much more sensitively to environmental changes than does the fine-root vegetative ectomycorrhizal community, it may more quickly reflect whether an ecosystem has been perturbed. It will also allow us to collect data on saprotrophic species. A sporocarp survey can be useful for detecting early changes in the habitat and environment, and give an easily applicable method for conservation biology and ecosystem management.

scholarly journals Nondestructive estimation of potato yield using relative variables derived from multi-period LAI and hyperspectral data based on weighted growth stage

Plant Methods ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Shanjun Luo ◽  
Yingbin He ◽  
Qian Li ◽  
Weihua Jiao ◽  
Yaqiu Zhu ◽  
...  
Keyword(s):  
Precision Agriculture ◽  
Growth Stage ◽  
Estimation Error ◽  
Potato Yield ◽  
Hyperspectral Data ◽  
Single Stage ◽  
Accurate Estimation ◽  
Yield Estimation ◽  
Area Index ◽  
Red Edge

Abstract Background The accurate estimation of potato yield at regional scales is crucial for food security, precision agriculture, and agricultural sustainable development. Methods In this study, we developed a new method using multi-period relative vegetation indices (rVIs) and relative leaf area index (rLAI) data to improve the accuracy of potato yield estimation based on the weighted growth stage. Two experiments of field and greenhouse (water and nitrogen fertilizer experiments) in 2018 were performed to obtain the spectra and LAI data of the whole growth stage of potato. Then the weighted growth stage was determined by three weighting methods (improved analytic hierarchy process method, IAHP; entropy weight method, EW; and optimal combination weighting method, OCW) and the Slogistic model. A comparison of the estimation performance of rVI-based and rLAI-based models with a single and weighted stage was completed. Results The results showed that among the six test rVIs, the relative red edge chlorophyll index (rCIred edge) was the optimal index of the single-stage estimation models with the correlation with potato yield. The most suitable single stage for potato yield estimation was the tuber expansion stage. For weighted growth stage models, the OCW-LAI model was determined as the best one to accurately predict the potato yield with an adjusted R2 value of 0.8333, and the estimation error about 8%. Conclusion This study emphasizes the importance of inconsistent contributions of multi-period or different types of data to the results when they are used together, and the weights need to be considered.

How forests change transit times of transpiration, evaporation and streamflow – a modeling approach

2021 ◽  
Author(s):  
Ingo Heidbüchel ◽  
Jie Yang ◽  
Jan H. Fleckenstein
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Water Cycle ◽  
Rooting Depth ◽  
Water Fluxes ◽  
Area Index ◽  
Transit Times ◽  
Physically Based ◽  
Forested Areas ◽  
The Individual

<p>In a recent paper we investigated how different catchment and climate properties influence transit time distributions. This was done by employing a physically-based spatially explicit 3D model in a virtual catchment running many different scenarios with different combinations of catchment and climate properties. We found that the velocity distribution of water fluxes through a catchment is more sensitive to certain properties while other factors appear less relevant. Now we expanded the approach by adding vegetation to the model and thus introducing new hydrologic processes (transpiration and evaporation) to the simulated water cycle. On the one hand we wanted to know how these new processes would influence transit times of the water fluxes to the stream, on the other hand we were interested in how exactly differences in the vegetation itself (e.g. rooting depth and leaf area index) would alter the various flux velocities (including transit times of transpiration and evaporation). It was very interesting to observe that streamflow in forested areas appeared to become older on average. We also found that transpiration was generally younger if the vegetation had shallower roots and/or a larger leaf area index. The biggest difference in the age of evaporation was detected for different amounts of subsequent precipitation (evaporation was generally younger in a wetter climate). In conclusion, we found that forests influence the age of the different water fluxes within a catchment. According to our results the overall hydrologic cycle is decelerated when adding vegetation to a model that otherwise only simulates evaporation.</p><p>Still, in order to make meaningful predictions on the age of hydrologic fluxes, it is not constructive to single out specific catchment and climate properties. The multitude of influences from different parameters makes it very challenging to find rules and underlying principles in the integrated catchment response. Therefore it is necessary to look at the individual parameters and their potential interactions and interdependencies in a bottom-up approach.</p>

scholarly journals MORPHOLOGICAL AND PRODUCTIVE CHARACTERIZATION OF FORAGE CACTUS VARIETIES

2015 ◽  
Vol 28 (3) ◽  
pp. 230-238 ◽  
Author(s):  
PHILIPE LIMA DE AMORIM ◽  
JANAINA AZEVEDO MARTUSCELLO ◽  
JOSÉ TEODORICO DE ARAÚJO FILHO ◽  
DANIEL DE NORONHA FIGUEIREDO VIEIRA DA CUNHA ◽  
LIANA JANK
Keyword(s):  
Block Design ◽  
Morphological Characteristics ◽  
Correlation Coefficients ◽  
Dry Mass ◽  
Negative Effects ◽  
Breeding Programs ◽  
Area Index ◽  
Promising Alternative ◽  
Randomized Block Design ◽  
Use Efficiency

ABSTRACT: Cultivars of the genus Nopalea are known in Brazil for being tolerant to cochineal carmine attacks, thus making the cultivation of this genus a promising alternative for mitigating the negative effects of this insect on the production of biomass. With the objectives of characterizing morphologically spineless forage cactus varieties and identify morphological characteristics that may be the focus in spineless forage cactus breeding programs, an experiment was conducted in a completely randomized block design with 11 treatments and four replications. The variety Alagoas showed the highest values of weight, area and volume of cladodes. The varieties Negro Michoacan F7 and V7, Tamazunchale V12 showed the highest values of the cladode area index, the total volume of cladodes and total fresh mass production. The varieties Negro Michoacan V7 and F7 presented the highest water use efficiency and dry mass yield. Cladode volume showed the highest correlation coefficients with the fresh weight of cladodes. Aiming the release of varieties for biomass production, varieties Negro Michoacan F7, V7 and Tamazunchale V12 may substitute the Miúda variety. The number and cladode area index may be used as criteria for selection of superior varieties in breeding programs.

Mapping and monitoring intertidal benthic habitats: a review of techniques and a proposal for a new visual methodology for the European coasts

2009 ◽  
Vol 33 (3) ◽  
pp. 378-402 ◽  
Author(s):  
Laurent Godet ◽  
Jérôme Fournier ◽  
Nicolas Toupoint ◽  
Frédéric Olivier
Keyword(s):  
Environmental Changes ◽  
Coastal Zones ◽  
Quick Method ◽  
Simple Method ◽  
Long Term Monitoring ◽  
Intertidal Habitats ◽  
Global Environmental Changes ◽  
Remote Sensing Methods ◽  
Term Monitoring

Mapping seafloors is a fundamental step for managing and preserving coastal zones. Moreover, in a context of current global environmental changes, new methods allowing long-term monitoring are increasingly required. Various methods have been used to map seafloors, primarily benthic macrofauna and sediment sampling along regular grids or transects, and remote sensing methods. These methods map very different things, do not have the same accuracy levels, and have different costs in time and money. Furthermore, such methods often require the competencies of highly skilled scientists and exclude non-specialists otherwise best placed to perform them. In this paper, we test a method based on Direct Field Observations (‘DFO method’), which can be used by non-specialists, and assess if it is sufficient for mapping and monitoring intertidal habitats. We further compare this method with other conventional ones. The results show that such a simple method is relatively rapid and inexpensive given the results obtained. Moreover, it is particularly suitable for highly fragmented intertidal landscapes where other methods are often very limited. In consequence, in areas such as the European coasts, it can be used by non-specialists, such as protected-area managers, and because it is an inexpensive and quick method long-term monitoring is also possible.

scholarly journals DESENVOLVIMENTO DO TOMATEIRO INDUSTRIAL EM RESPOSTA A DIFERENTES NÍVEIS DE IRRIGAÇÃO

Irriga ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 432-448
Author(s):  
Cícero José da Silva ◽  
José Antônio Frizzone ◽  
César Antônio da Silva ◽  
Nadson de Carvalho Pontes ◽  
Luiz Felipe Mariano da Silva ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Development ◽  
Tomato Plant ◽  
Dry Mass ◽  
Area Index ◽  
Tomato Plants ◽  
Subsurface Drip ◽  
Irrigation Levels ◽  
E Mail

DESENVOLVIMENTO DO TOMATEIRO INDUSTRIAL EM RESPOSTA A DIFERENTES NÍVEIS DE IRRIGAÇÃO     Cícero José da Silva1; José Antônio Frizzone2; César Antônio da Silva3; Nadson de Carvalho Pontes4; Luiz Felipe Mariano da Silva5 E Ênio Eduardo Basílio6   1Professor do Curso Bacharelado em Agronomia, Instituto Federal Goiano – Campus Morrinhos – GO, BR 153, Km 633, Zonal Rural, CEP;75650-000, Morrinhos – GO, Brasil. E-mail: [email protected] 2Professor Aposentado Colaborador Senior, Departamento de Engenharia de Biossitemas, Escola Superior de Agricultura “Luiz de Queiroz” – Universidade de São Paulo, Avenida Pádua Dias, N 11, Caixa Postal 9, CEP: 13418-900, Piracicaba – SP, Brasil. E-mail: [email protected] 3Professor do Curso Bacharelado em Agronomia, Instituto Federal Goiano – Campus Morrinhos – GO, BR 153, Km 633, Zonal Rural, CEP;75650-000, Morrinhos – GO, Brasil. E-mail: [email protected] 4Professor do Curso Bacharelado em Agronomia, Instituto Federal Goiano – Campus Morrinhos – GO, BR 153, Km 633, Zonal Rural, CEP;75650-000, Morrinhos – GO, Brasil. E-mail: [email protected] 5Estudante de Iniciação Científica do Curso Bacharelado em Agronomia, Instituto Federal Goiano – Campus Morrinhos – GO, BR 153, Km 633, Zonal Rural, CEP;75650-000, Morrinhos – GO, Brasil. E-mail: [email protected] 6Técnico Administrativo, Mestre em Olericultura, Instituto Federal Goiano – Campus Morrinhos – GO, BR 153, Km 633, Zonal Rural, CEP;75650-000, Morrinhos – GO, Brasil. E-mail: [email protected]     1 RESUMO   O objetivo desta pesquisa foi avaliar o desenvolvimento de plantas de tomateiros submetidas a diferentes níveis de reposição da irrigação, aplicados via sistema gotejamento subsuperficial durante duas safras. O experimento foi conduzido no delineamento em blocos ao acaso, com quatro repetições. Foram avaliados cinco níveis de irrigação: 50, 75, 100, 125 e 150% da evapotranspiração da cultura (%ETc) medida com lisímetros de pesagem, sobre o desenvolvimento de plantas de tomateiro. Cada parcela experimental foi composta por três fileiras de plantas de 5,5 m de comprimento, espaçadas a 1,10 m entre si e 0,30 m entre plantas. As avaliações de área foliar, índice de área foliar, massa seca de raiz, caule, folhas, flores, frutos e total foram realizadas aos 45, 65 e 85 dias após o transplante das mudas. Irrigações deficitárias e em excesso prejudicaram o desenvolvimento vegetativo das plantas de tomateiro. Os maiores valores de área foliar, índice de área foliar e massa seca total das plantas de tomateiro foram estimados com níveis de irrigação que variaram de 96 a 112% da ETc, variando de acordo com o ano de avaliação e a fase de desenvolvimento do tomateiro. Irrigações deficitárias e excessivas prejudicaram a floração e frutificação do tomateiro híbrido BRS Sena.             Palavras-chave: Solanum lycopersicom L.; gotejamento enterrado; manejo da irrigação; massa seca.             Silva, c. j. da; FRIZZONE, J. A.; SILVA, C. A. da; pontes, n. de C.; SILVA, L. F. M. da; BASÍLIO, Ê. E. Industrial tomato plant development in response to different irrigation levels    2 ABSTRACT   This research aimed to evaluate tomato plant development submitted to different irrigation replacement levels, irrigated via subsurface drip system for two harvests. The experiment was conducted under a randomized complete block design with four replications. Five irrigation levels were evaluated: 50, 75, 100, 125 and 150% of crop evapotranspiration (% ETc) measured with weighing lysimeters over the tomato plants development. Each experimental plot was composed of three plants rows with 5.5 m long, spaced 1.10 m apart and 0.30 m between plants. Leaf area, leaf area index, root dry matter, stem, leaves, flowers, fruits and total were evaluated at 45, 65 and 85 days after seedlings transplanting. Deficit and excess irrigation impaired the vegetative development of tomato plants. The highest values of leaf area, leaf area index and plants total dry mass were estimated with irrigation levels ranging from 96 to 112% of ETc, depending on the evaluation harvest year and the crop development phase. Deficit and excessive irrigation affected the flowering and fruiting of the hybrid tomato BRS Sena.   Keywords: Solanum lycopersicom L; subsurface drip irrigation; irrigation manegement; dry mass.

scholarly journals An automated procedure for estimating the leaf area index (LAI) of woodland ecosystems using digital imagery, MATLAB programming and its application to an examination of the relationship between remotely sensed and field measurements of LAI

2008 ◽  
Vol 35 (10) ◽  
pp. 1070 ◽  
Author(s):  
Sigfredo Fuentes ◽  
Anthony R. Palmer ◽  
Daniel Taylor ◽  
Melanie Zeppel ◽  
Rhys Whitley ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Gap Analysis ◽  
Digital Camera ◽  
Field Measurements ◽  
Accurate Estimation ◽  
Image Capture ◽  
Area Index ◽  
Modis Lai ◽  
Matlab Programming

Leaf area index (LAI) is one of the most important variables required for modelling growth and water use of forests. Functional–structural plant models use these models to represent physiological processes in 3-D tree representations. Accuracy of these models depends on accurate estimation of LAI at tree and stand scales for validation purposes. A recent method to estimate LAI from digital images (LAID) uses digital image capture and gap fraction analysis (Macfarlane et al. 2007b) of upward-looking digital photographs to capture canopy LAID (cover photography). After implementing this technique in Australian evergreen Eucalyptus woodland, we have improved the method of image analysis and replaced the time consuming manual technique with an automated procedure using a script written in MATLAB 7.4 (LAIM). Furthermore, we used this method to compare MODIS LAI values with LAID values for a range of woodlands in Australia to obtain LAI at the forest scale. Results showed that the MATLAB script developed was able to successfully automate gap analysis to obtain LAIM. Good relationships were achieved when comparing averaged LAID and LAIM (LAIM = 1.009 – 0.0066 LAID; R2 = 0.90) and at the forest scale, MODIS LAI compared well with LAID (MODIS LAI = 0.9591 LAID – 0.2371; R2 = 0.89). This comparison improved when correcting LAID with the clumping index to obtain effective LAI (MODIS LAI = 1.0296 LAIe + 0.3468; R2 = 0.91). Furthermore, the script developed incorporates a function to connect directly a digital camera, or high resolution webcam, from a laptop to obtain cover photographs and LAI analysis in real time. The later is a novel feature which is not available on commercial LAI analysis softwares for cover photography. This script is available for interested researchers.

Virtual Ground Fence: A Simple Method for Protection against High Frequency Simultaneous Switching Noise

2012 ◽  
Vol 2012 (1) ◽  
pp. 001081-001084 ◽  
Author(s):  
Jesse Bowman ◽  
A. Ege Engin
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Power Efficiency ◽  
Printed Circuit Board ◽  
Supply Voltage ◽  
Circuit Board ◽  
Voltage Source ◽  
Accurate Estimation ◽  
Simple Method ◽  
Power Distribution System

When integrating sensitive RF analog devices with complex VLSI digital components, simultaneously switching drivers cause supply voltage fluctuations which can propagate both horizontally and vertically between the power/ground planes. The same voltage source on a printed circuit board can be shared to increase power efficiency and reduce space used. In order to accomplish this, on board filtering is needed to isolate the noise between these two types of devices for proper operation. Hence, accurate estimation and improvement of the performance of power/ground planes is critical in a mixed-signal system. We present a new method to minimize the noise transfer at high frequencies to the power distribution system, called the Virtual Ground Fence. At its basic level, the Virtual Ground Fence consists of quarter-wave transmission-line stubs that act as short circuits between power and ground planes at their design frequency. We will present various configurations of Virtual Ground Fence for different coupling scenarios.

scholarly journals Modelling Canopy Actual Transpiration in the Boreal Forest with Reduced Error Propagation

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1158
Author(s):  
M. Rebeca Quiñonez-Piñón ◽  
Caterina Valeo
Keyword(s):  
Error Propagation ◽  
Climate Change Impacts ◽  
Field Measurements ◽  
Sap Flux ◽  
Area Index ◽  
Sapwood Area ◽  
Canopy Transpiration ◽  
Tree Sap ◽  
Forested Areas ◽  
Monteith Equation

The authors have developed a scaling approach to aggregate tree sap flux with reduced error propagation in modeled estimates of actual transpiration () of three boreal species. The approach covers three scales: tree point, single tree trunk, and plot scale. Throughout the development of this approach the error propagated from one scale to the next was reduced by analyzing the main sources of error and exploring how some field and lab techniques, and mathematical modeling can potentially reduce the error on measured or estimated parameters. Field measurements of tree sap flux at the tree point scale are used to obtain canopy transpiration estimates at the plot scale in combination with allometric correlations of sapwood depth (measured microscopically and scaled to plots), sapwood area, and leaf area index. We compared the final estimates to actual evapotranspiration and actual transpiration calculated with the Penman–Monteith equation, and the modified Penman–Monteith equation, respectively, at the plot scale. The scaled canopy transpiration represented a significant fraction of the forest evapotranspiration, which was always greater than 70%. To understand climate change impacts in forested areas, more accurate actual transpiration estimates are necessary. We suggest our model as a suitable approach to obtain reliable estimates in forested areas with low tree diversity.

Estimating Fractional Snow Cover in Mountain Environments with Fuzzy Classification

2012 ◽  
Vol 3 (3) ◽  
pp. 1-20 ◽  
Author(s):  
Clayton J. Whitesides ◽  
Matthew H. Connolly
Keyword(s):  
Snow Cover ◽  
Snow Water Equivalent ◽  
Recursive Partitioning ◽  
Fuzzy Classification ◽  
Model Parameters ◽  
Water Runoff ◽  
Simple Method ◽  
Primary Input ◽  
Area Index ◽  
Fractional Snow Cover

The disproportionate amount of water runoff from mountains to surrounding arid and semiarid lands has generated much research in snow water equivalent (SWE) modeling. A primary input in SWE models is snow covered area (SCA) which is generally obtained via satellite imagery. Mixed pixels in alpine snow studies complicate SCA measurements and can reduce accuracy. A simple method was developed to estimate fractional snow cover using freely available Landsat and data derived from DEMs, commercial and free software, as well as fuzzy classification and recursive partitioning. The authors attempted to develop a cost effective technique for estimating fractional snow cover for resource and recreation managers confined by limited budgets and resources. Results indicated that the method was non-sensitive (P = 0.426) to differences in leaf area index and solar radiation between 4 March 2000 and 13 March 2003. Fractional snow cover was predicted consistently despite variation in model parameters between years, indicating that the developed method may be a viable way for monitoring fractional snow cover in mountainous areas where capital and resources are limited.

scholarly journals Adjusting Ceptometer Data to Improve Leaf Area Index Measurements

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 866 ◽  
Author(s):  
Klára Pokovai ◽  
Nándor Fodor
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Measurement Techniques ◽  
Well Being ◽  
Average Error ◽  
Light Conditions ◽  
Simple Method ◽  
Area Index ◽  
Expert Opinions ◽  
Optimal Illumination

Leaf Area Index (LAI) is an important plant parameter for both farmers and plant scientists to monitor and/or model the growth and the well-being of plants. Since direct LAI measurement techniques are relatively laborious and time-consuming, various indirect methods have been developed and widely used since the early 1990s. The LP-80 ceptometer uses a linear array of PAR (photosynthetically active radiation) sensors for non-destructive LAI measurements that is backed by 15 years of research. Despite this, considerable discrepancy can be found between the expert opinions regarding the optimal illumination conditions recommended for the measurement. The sensitivity of ceptometer-based LAI values to PAR was investigated, and a simple method was devised to correct raw ceptometer data collected under non-ideal light conditions. Inadequate light conditions (PAR < 1700 µmol m−2 s−1) could cause an underestimation of LAI. Using the corrected LAI values, the ceptometer data showed a significantly better fit (higher R2, smaller mean average error and closer to zero mean signed error values) to the destructive LAI data for both wheat and maize. With the help of the correction equations, the use of the LP-80 ceptometer could be extended to days when light conditions are not ideal.

Sign in / Sign up

Export Citation Format

Share Document