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In strawberry (Fragaria ×ananassa), initial bare-root crown diameter and early-season flower cluster removal have been two factors suspected of influencing fruit yield and size. This study evaluated the effect of these two factors on the day-neutral strawberry varieties Monterey and Cabrillo. Bare-root crowns with three different diameters were categorized into small (< 0.5 cm), medium (> 0.5 to 1 cm), and large (> 1 cm) at planting. Each of the crown diameter treatments was split into two plots for flower removal or no flower removal in the early season and data on canopy diameter, fruit yield, and fruit size collected in the subsequent months of production. The study was conducted over two growing seasons (2019–20 and 2020–21). No difference was found in plant canopy diameters measured in February, ∼3 months after planting, between any of the treatments in either year. Although early-season flower removal and some crown sizes resulted in lower fruit yield in March and April, none of these treatments resulted in any fruit yield or size differences in subsequent months nor in season end totals.

Grazing and precipitation are pivotal factors influencing the productivity and biodiversity of grassland ecosystems, largely through their effects on the growth and reproduction of dominant species. Approximately 50 % of terrestrial ecosystems are concurrently affected by grazing and precipitation addition (PA), yet the interactive effects of these factors remain underexplored. To elucidate the combined impacts of grazing and PA on the growth of dominant species and their influence on community structure and function, we initiated a four-year combined grazing and PA experiment based on a long term of grazing experiment in a typical steppe. The synergistic interaction between PA and grazing enhanced canopy diameter (CD), tiller density (TD), and seedling density (SD) in dominant species, while decreasing reproductive branch density (RB). Conversely, an antagonistic interaction increased plant height (PH) and TD but reduced SD. These responses suggest that dominant species adapt to combined grazing and PA pressures by shifting growth strategies towards lateral growth and asexual reproduction. The growth characteristics of dominant species exhibited four response patterns to grazing and PA interactions: full saturation, sufficient saturation, equal saturation, and deficit saturation, each with three corresponding thresholds: adaptation, optimum, and saturation points. Grazing decreased the precipitation response thresholds for PH, CD, RB, and population density, while increasing the optimal points for TD and SD. These changes in the growth of the dominant species resulted in a 33 % reduction in the aboveground biomass (AGB) of the community and triggered a 18 % increase in the coupling index between AGB and species richness within the community. Our findings highlight the role of dominant species in facilitating community adaptation to increased precipitation and rotational grazing, offering critical insights for developing sustainable grazing strategies under climate change. [Display omitted] • Effects of the interaction of grazing and precipitation addition on population growth. • Contribution of population changes to community structure and functioning. • Grazing and precipitation addition have synergistic effects on growth indicators. • Plant height and population density were the most sensitive to synergistic effects. • Grazing and precipitation addition increase the competitiveness of Stipa bungeana. [ABSTRACT FROM AUTHOR]

Woody structure, particularly that created by large trees, is crucial to savanna biodiversity pattern and process. We assessed changes in vertical and horizontal canopy over 15 years of saplings of Vachellia (Acacia) erioloba (camelthorn), a keystone species and one of the only trees to grow large in arid savanna on low rainfall areas of Kalahari sands, southern Africa. We also assessed whether the fastest growing saplings over the 2003–2004 growing season were also the fastest growing over the following 15 years. We measured height, canopy extent, and diameter of largest stem at ground level of 120 saplings of V. erioloba in November 2003, remeasuring these in March 2004. In November 2019, we were able to find 67 of these saplings, and we measured them again to assess growth between 2004 and 2019. We modeled interindividual explanatory variables for growth (i.e., measures taken in 2004 of height, diameter, number of stems, evidence of fire, and largest stem diameter). We also compared residuals of growth between 2003 and 2004 with those between 2004 and 2019, to assess whether individuals showed similar progress relative to their peers over the two periods considered. Height increase was extremely variable, but mean increase over 15 years was only 45.4 mm, similar to that measured for the 2003–2004 growing season (43.1 mm). Mean horizontal canopy showed far greater growth (mean 120.2 mm over 15 years, compared with 7.12 mm over 2003–2004) than vertical growth. Individuals that had shown the fastest increase in horizontal canopy in 2003–2004 tended to be the same individuals that grew fastest over the following 15 years, but even the highest "achievers" showed increases of only 47.2 mm and 37.5 mm year−1 in average horizontal canopy extent and height, respectively. This study demonstrates how crucial long‐term studies are, particularly in arid systems. Many individuals may be trapped in the "sapling" class and could take decades to become large trees. Woody sapling growth was not cumulative, and modeling studies in savannas should be cautious in extrapolating growth from one season to several years. [ABSTRACT FROM AUTHOR]

Abstract Woody structure, particularly that created by large trees, is crucial to savanna biodiversity pattern and process. We assessed changes in vertical and horizontal canopy over 15 years of saplings of Vachellia (Acacia) erioloba (camelthorn), a keystone species and one of the only trees to grow large in arid savanna on low rainfall areas of Kalahari sands, southern Africa. We also assessed whether the fastest growing saplings over the 2003–2004 growing season were also the fastest growing over the following 15 years. We measured height, canopy extent, and diameter of largest stem at ground level of 120 saplings of V. erioloba in November 2003, remeasuring these in March 2004. In November 2019, we were able to find 67 of these saplings, and we measured them again to assess growth between 2004 and 2019. We modeled interindividual explanatory variables for growth (i.e., measures taken in 2004 of height, diameter, number of stems, evidence of fire, and largest stem diameter). We also compared residuals of growth between 2003 and 2004 with those between 2004 and 2019, to assess whether individuals showed similar progress relative to their peers over the two periods considered. Height increase was extremely variable, but mean increase over 15 years was only 45.4 mm, similar to that measured for the 2003–2004 growing season (43.1 mm). Mean horizontal canopy showed far greater growth (mean 120.2 mm over 15 years, compared with 7.12 mm over 2003–2004) than vertical growth. Individuals that had shown the fastest increase in horizontal canopy in 2003–2004 tended to be the same individuals that grew fastest over the following 15 years, but even the highest “achievers” showed increases of only 47.2 mm and 37.5 mm year−1 in average horizontal canopy extent and height, respectively. This study demonstrates how crucial long‐term studies are, particularly in arid systems. Many individuals may be trapped in the “sapling” class and could take decades to become large trees. Woody sapling growth was not cumulative, and modeling studies in savannas should be cautious in extrapolating growth from one season to several years.

Growth strategies of plant populations plays an important role in biodiversity and productivity of community while over half 77% of global terrestrial ecosystem is used for grazing and simultaneously 30%-40% is exposed to precipitation addition (PA). However, the combined effects of grazing and PA on plant population growth and their relationship with community characteristics remain poorly understood, largely due to the limited number and quality of field experiments. Hereby, a four-year PA experiment was conducted in long-term grazed paddocks in a typical steppe, which aimed to compare the effects of both grazing and PA on the growth, reproduction, and trade-offs between dominant and companion species. The interaction between grazing and PA prompted the dominant species to adopt a horizontal growth strategy and sexual reproduction, allocating 69 % of its resources to offspring production, whereas the companion species opted for a vertical growth strategy and asexual reproduction, allocating 87 % of its resources to individual survival and dispersal. This trade-off strategy increased the proportion of dominant species while companion species remained stable, and PA mitigated this trend while concurrently decreasing the proportion of other species within the community. The interaction between grazing and PA promotes the coupling of aboveground biomass and species riches in community by decreasing plant height of dominant and companion species and increasing canopy diameter of companion species. There were mainly four biotic response curves of dominant and companion species to grazing and PA interaction: full saturation, sufficient saturation, equal saturation, and deficit saturation. Correspondingly, there were three pairs of threshold values for three phases of each pattern. Our study reveals how communities improve their adaptability by regulating population growth, providing important insights for developing sustainable grazing management strategies under global climate change. • The grazing and precipitation addition interactively affect population growth. • Population changes contribute to community structure and functioning. • Changes in aboveground biomass and species richness affect population growth. [ABSTRACT FROM AUTHOR]

Abstract Background Determining the spatial distribution of tree heights at the regional area scale is significant when performing forest above-ground biomass estimates in forest resource management research. The geometric-optical mutual shadowing (GOMS) model can be used to invert the forest canopy structural parameters at the regional scale. However, this method can obtain only the ratios among the horizontal canopy diameter (CD), tree height, clear height, and vertical CD. In this paper, we used a semi-variance model to calculate the CD using high spatial resolution images and expanded this method to the regional scale. We then combined the CD results with the forest canopy structural parameter inversion results from the GOMS model to calculate tree heights at the regional scale. Results The semi-variance model can be used to calculate the CD at the regional scale that closely matches (mainly with in a range from − 1 to 1 m) the CD derived from the canopy height model (CHM) data. The difference between tree heights calculated by the GOMS model and the tree heights derived from the CHM data was small, with a root mean square error (RMSE) of 1.96 for a 500-m area with high fractional vegetation cover (FVC) (i.e., forest area coverage index values greater than 0.8). Both the inaccuracy of the tree height derived from the CHM data and the unmatched spatial resolution of different datasets will influence the accuracy of the inverted tree height. And the error caused by the unmatched spatial resolution is small in dense forest. Conclusions The semi-variance model can be used to calculate the CD at the regional scale, together with the canopy structure parameters inverted by the GOMS model, the mean tree height at the regional scale can be obtained. Our study provides a new approach for calculating tree height and provides further directions for the application of the GOMS model.

Intercropping Moldavian balm with mung bean is an ecological approach for improving resource productivity. A field experiment was conducted over two growing seasons (2018 and 2019) to determine the effect of fertilizer application on yield and essential oil (EO) productivity of Moldavian balm intercropped with mung bean. The experiment had a two‐factor randomized complete block design (RCBD) with three replicates. The first factor comprised of five cropping patterns: Moldavian balm sole crop (MBs), mung bean sole crop (MGs), one row each of Moldavian balm +mung bean (1MB:1MG), two rows each of Moldavian balm +mung bean (2MB:2MG), and three rows of Moldavian balm +two rows of mung bean (3MB:2MG). The second factor comprised four fertilizer sources: no fertilizer application (C, control), 100% chemical fertilizer (NPK), 50% chemical fertilizer +100% bacterial fertilizer (NPK+BF), and 100% bacterial fertilizer +100% mycorrhizal fungi (BF+MF). The sole crop fertilized with NPK+BF produced the highest seed yields for MG (1189 kg/ha) and MB (7027 kg/ha), while 3MB:2MG fertilized with NPK+BF had the highest nutrient contents. Moldavian balm produced the highest EO content and yield in 2MB:2MG fertilized with NPK+BF. The EO of MB mainly comprised geranyl acetate (30–39%), geranial (20–31%), neral (18–24%), and geraniol (3–8%). In addition, the 3MB:2MG intercropping treatment fertilized with NPK+BF had the highest land equivalent ratio (LER = 1.35). We recommend an intercropping ratio of 2MB:2MG fertilized with NPK+BF is recommended as an alternative and eco‐friendly strategy for farmers to improve EO quantity and quality. [ABSTRACT FROM AUTHOR]

Abstract Intercropping Moldavian balm with mung bean is an ecological approach for improving resource productivity. A field experiment was conducted over two growing seasons (2018 and 2019) to determine the effect of fertilizer application on yield and essential oil (EO) productivity of Moldavian balm intercropped with mung bean. The experiment had a two‐factor randomized complete block design (RCBD) with three replicates. The first factor comprised of five cropping patterns: Moldavian balm sole crop (MBs), mung bean sole crop (MGs), one row each of Moldavian balm +mung bean (1MB:1MG), two rows each of Moldavian balm +mung bean (2MB:2MG), and three rows of Moldavian balm +two rows of mung bean (3MB:2MG). The second factor comprised four fertilizer sources: no fertilizer application (C, control), 100% chemical fertilizer (NPK), 50% chemical fertilizer +100% bacterial fertilizer (NPK+BF), and 100% bacterial fertilizer +100% mycorrhizal fungi (BF+MF). The sole crop fertilized with NPK+BF produced the highest seed yields for MG (1189 kg/ha) and MB (7027 kg/ha), while 3MB:2MG fertilized with NPK+BF had the highest nutrient contents. Moldavian balm produced the highest EO content and yield in 2MB:2MG fertilized with NPK+BF. The EO of MB mainly comprised geranyl acetate (30–39%), geranial (20–31%), neral (18–24%), and geraniol (3–8%). In addition, the 3MB:2MG intercropping treatment fertilized with NPK+BF had the highest land equivalent ratio (LER = 1.35). We recommend an intercropping ratio of 2MB:2MG fertilized with NPK+BF is recommended as an alternative and eco‐friendly strategy for farmers to improve EO quantity and quality.

Some vegetative properties measured in fruit trees are important indicators in examining of plant growth calculation, estimation of leaf area index in evapotranspiration, fertilizer requirement etc. These measurements reflect the effects of the cultivation treatments in many areas of commercial growing and scientific studies. One of the most important measurements is the status of the canopy development. Canopy width, area and volume can be measured with some calculations. However, more technological equipment may be needed to reduce work and labor, and to make the results more precise and clearer. Recently, unmanned aerial vehicles, which have become widespread, have a wide potential for use in agriculture. By using image processing methods, it is possible to make more objective and high accuracy evaluations much faster. In this study, the images of the apple trees (Malus domestica Borkh) cultivar Golden grafted onto MM106 rootstock, were taken by light unmanned aerial vehicle to calculate the canopy area and then these images were analyzed using image processing methods for calculating canopy areas. Both circular and elliptical calculation methods were used. The area calculations with image processing methods were compared with the areas obtained manually. Comparisons were made by regression analysis. For the most successful method R value was 0.9662 for elliptic area and 0.9346 for circular area which was calculated by image processing. The results demonstrated that the image processing can be an alternative method to determine the canopy area according to accuracy ratios.

Background: Determining the spatial distribution of tree heights at the regional area scale is significant when performing forest above-ground biomass estimates in forest resource management research. The geometric-optical mutual shadowing (GOMS) model can be used to invert the forest canopy structural parameters at the regional scale. However, this method can obtain only the ratios among the horizontal canopy diameter (CD), tree height, clear height, and vertical CD. In this paper, we used a semi-variance model to calculate the CD using high spatial resolution images and expanded this method to the regional scale. We then combined the CD results with the forest canopy structural parameter inversion results from the GOMS model to calculate tree heights at the regional scale. Results: The semi-variance model can be used to calculate the CD at the regional scale that closely matches (mainly with in a range from − 1 to 1 m) the CD derived from the canopy height model (CHM) data. The difference between tree heights calculated by the GOMS model and the tree heights derived from the CHM data was small, with a root mean square error (RMSE) of 1.96 for a 500-m area with high fractional vegetation cover (FVC) (i.e., forest area coverage index values greater than 0.8). Both the inaccuracy of the tree height derived from the CHM data and the unmatched spatial resolution of different datasets will influence the accuracy of the inverted tree height. And the error caused by the unmatched spatial resolution is small in dense forest. Conclusions: The semi-variance model can be used to calculate the CD at the regional scale, together with the canopy structure parameters inverted by the GOMS model, the mean tree height at the regional scale can be obtained. Our study provides a new approach for calculating tree height and provides further directions for the application of the GOMS model. [ABSTRACT FROM AUTHOR]

The objective was to explore a fast, accurate, non-destructive, and less disturbance method for predicting the aboveground biomass (AGB) of the typical steppe, by using plant height and canopy diameter of the dominant species, Stipa bungeana, Artemisia capillaris, and Lespedeza davurica, data were observed from 165 quadrats during the peak plant growing season, and the product of plant height (PH) and canopy diameter (PC) were calculated for each species. AGB of population were predicted for the same species and other species through using 2/3 of the measured data, and the optimal predictive equation was linear in terms of determination coefficient. The other 1/3 of the data, which was measured from no grazing paddocks or rotational grazing paddocks, was substituted into the predictive equations for validation. Results showed that PC of one dominant species could be used to predict AGB of the same species or other species well. The predicted and measured values were significantly correlative, and most of the predictive accuracy was above 80%, and not affected by managements of grassland, including rotational grazing or no grazing. A combination of 3 to 6 representative species was used to predict AGB of the community, and the predictive equations with PC of six species as an independent variable were the most optimal because explaining 83.5% variation of AGB. The predictive methods cost 1/15, 1/9, and 1/51 of time, labor, and capital as much as the destructive sample method (quadrat sampling method), respectively, and thus improved the efficiency of field study and protecting the fragile study areas, especially the long-term study sites in grassland.

Rose-scented geranium oil is extracted from the shoots (mostly the leaves) of the Pelargonium spp. through steam- or hydro-distillation. To extract less than 0.2% oil, farmers must transport and distil bulky herbage. This makes geranium oil production costly, and high time- and energy-consuming process. To investigate the effect of different paclobutrazol (PBZ) concentrations (0, 100, 200, 300 mg/L of water) on vegetative growth, and oil yield and composition of rose-scented geranium, three pot experiments were conducted. The experiments were conducted in a glasshouse of the University of Fort Hare, Alice, South Africa (located at 25°45'S and 28°16'E, an altitude of 520 m above sea level), between Oct. 2011 and May 2013. The treatments were arranged in a randomized complete block design (RCBD) in four replications. The PBZ was sprayed on the plants at 1 month of regrowth stage. Chlorophyll content increased with concentration of PBZ. The reduction of plant height in all PBZ-treated plants was significant, ranged between 18% and 33%. Plant canopy also reduced by 5% to 23%, and the differences were more noticeable in the plants grown between January and May (summer/autumn season), producing compact plants. Leaf area and internode length reduced as PBZ concentration increased. Paclobutrazol had no significant effect on leaf number, and essential oil yield and composition. This implies that, through applying PBZ, compacted (less bulky) rose-scented geranium could be produced without significant change in essential oil yield per plant and essential oil composition. [ABSTRACT FROM AUTHOR]

Measuring plant height (y) and canopy diameter (x) in trees may not be an easy task, but stem diameter (z) can be more easily evaluated. This work's objective was two-fold: evaluate the growth of species adapted to the Brazilian Semi-Arid Region in the first two years of age, and obtain linear equations to estimate y and x from z, in those species. A random block design with four replications was employed. The values for x, z, and y were measured biannually from October/2003 to March/2005. Prosopis juliflora and Mimosa caesalpiniaefolia showed the highest stem diameter and plant height values, respectively, and both showed the highest canopy diameter. In the equations to estimate plant height from the stem diameter the value of the coefficient of determination (R²) ranged from 0.76 (Tamarindus indica and Leucaena leucocephala) to 0.92 (Prosopis juliflora and Azadirachta indica). In the equations that allowed to estimate the crown diameter from the stem diameter the R² value ranged from 0.70 (Leucaena leucocephala) to 0.92 (Azadirachta indica).A mensuração da altura da planta (y) e do diâmetro da copa (x) em árvores pode não ser tarefa fácil, mas o diâmetro do caule (z) pode ser avaliado mais facilmente. Este trabalho teve por objetivos avaliar o crescimento de espécies adaptadas ao Semi-Árido brasileiro, nos primeiros dois anos de idade, e obter equações lineares para estimar y e x a partir de z, nessas espécies. Utilizou-se o delineamento de blocos ao acaso com quatro repetições. Os valores de x, z e y foram medidos semestralmente de outubro/2003 a março/2005. Prosopis juliflora e Mimosa caesalpiniaefolia apresentaram os maiores diâmetros do caule e altura da planta, respectivamente, e ambas apresentaram o maior diâmetro da copa. Nas equações para estimar a altura da planta a partir do diâmetro do caule, o valor do coeficiente de determinação (R²) variou de 0,76 (Tamarindus indica and Leucaena leucocephala) a 0,92 (Prosopis juliflora and Azadirachta indica). Nas equações que permitiram estimar o diâmetro da copa a partir do diâmetro do caule, o valor de R² variou de 0,70 (Leucaena leucocephala) a 0,92 (Azadirachta indica).

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Abstract: Determination of aboveground biomass (AGB) is an important step in planning the protection and sustainable use of mangrove resources. In the present paper, allometric relationships for estimating AGB of different morphology mangrove trees on the basis of canopy diameter (CD) and tree height (H) were studied. By comparing of correlation between AGB and CD2*H, and of relative error rates between measurement value and simulation value within the three mangrove specie, results show that regression equation, in the form of AGB=a(CD2*H)b, is very suitable for estimation of AGB of multi-stemmed mangrove trees such as Aegiceras corniculatum, and is not suitable for single- stemmed mangrove trees such as Kandelia candel, but may be applied to those mangrove trees between multi- stemmed and single-stemmed in morphology such as Avicennia marina. [Copyright &y& Elsevier]

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective was to explore a fast, accurate, non-destructive, and less disturbance method for predicting the aboveground biomass (AGB) of the typical steppe, by using plant height and canopy diameter of the dominant species, Stipa bungeana, Artemisia capillaris, and Lespedeza davurica, data were observed from 165 quadrats during the peak plant growing season, and the product of plant height (PH) and canopy diameter (PC) were calculated for each species. AGB of population were predicted for the same species and other species through using 2/3 of the measured data, and the optimal predictive equation was linear in terms of determination coefficient. The other 1/3 of the data, which was measured from no grazing paddocks or rotational grazing paddocks, was substituted into the predictive equations for validation. Results showed that PC of one dominant species could be used to predict AGB of the same species or other species well. The predicted and measured values were significantly correlative, and most of the predictive accuracy was above 80%, and not affected by managements of grassland, including rotational grazing or no grazing. A combination of 3 to 6 representative species was used to predict AGB of the community, and the predictive equations with PC of six species as an independent variable were the most optimal because explaining 83.5% variation of AGB. The predictive methods cost 1/15, 1/9, and 1/51 of time, labor, and capital as much as the destructive sample method (quadrat sampling method), respectively, and thus improved the efficiency of field study and protecting the fragile study areas, especially the long-term study sites in grassland. [ABSTRACT FROM AUTHOR]