scholarly journals Effects of fertilisation on grass and forb gamic reproduction in semi-natural grasslands

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michele Scotton ◽  
Valentina Rossetti
Keyword(s):  
Seed Production ◽  
Soil Nutrient ◽  
Shoot Density ◽  
Maturation Stage ◽  
Variable Effect ◽  
Grassland Species ◽  
Natural Grasslands ◽  
Soil Eutrophication ◽  
Viable Seeds ◽  
The Relationship

AbstractStudying the effects of fertilisation on the seed production of grassland species can help understand the vegetation changes and biodiversity losses due to soil eutrophication. The seed production of fifteen grasses and seventeen forbs from a temperate hay meadow was studied under three fertilisation treatments: 0-0-0, 0-54-108 and 192-108-216 kg N, P2O5 and K2O respectively, per year. Fertile shoots collected at the seed maturation stage were analysed for all main traits of the gamic reproduction. On average, forbs produced more ovules and viable seeds per shoot (199 and 65, respectively) than grasses (112 and 35, respectively). Fertilisation increased the number of inflorescences per shoot in both grasses and forbs and had a limited but variable effect on germinability and viability in the two functional groups: viability increased in grasses but often decreased in forbs. This pattern resulted in 55% and 11% increases in viable seed production in grasses and forbs, respectively. At the higher level of fertilisation, shoot density was positively related to the number of viable seeds per shoot in grasses and to the seed size in forbs. These results highlight that the traits of the gamic reproduction can contribute to explain the relationship between soil nutrient richness and grassland species composition and richness.

scholarly journals Effects of Fertilisation on Grass and Forb Gamic Reproduction in Semi-natural Grasslands

2021 ◽  
Author(s):  
Michele Scotton ◽  
Valentina Rossetti
Keyword(s):  
Seed Production ◽  
Shoot Density ◽  
Maturation Stage ◽  
Vegetation Changes ◽  
Variable Effect ◽  
Grassland Species ◽  
Grass Seed ◽  
Natural Grasslands ◽  
Soil Eutrophication ◽  
Viable Seeds

Abstract Studying the effects of fertilisation on the seed production of grassland species can help understand the vegetation changes and biodiversity losses due to soil eutrophication. On a temperate hay-meadow, the seed production of fifteen grasses and seventeen forbs was studied under three fertilisation treatments: 0-0-0, 0-54-108 and 192-108-216 kg N, P2O5 and K2O respectively, per year. Fertile shoots collected at the seed maturation stage were analysed for all main traits of the gamic reproduction. On average, forbs produced more ovules and viable seeds per shoot (199 and 65, respectively) than grasses (112 and 35, respectively). Fertilisation increased the number of inflorescences per shoot in both grasses and forbs and had a limited but variable effect on germinability and viability in the two functional groups: viability increased in grasses but often decreased in forbs. This pattern resulted in 55% and 11% increases in viable seed production in grasses and forbs, respectively. At the higher level of fertilisation, shoot density was positively related to the number of viable seeds per shoot in grasses and to the seed size in forbs. Higher grass seed dormancy likely allowed for later grass seed germination in autumn when vegetation cover was low, contributing to the dominance of a few light-seeded nutrient-demanding grasses and poor forb number in fertilised meadows.

scholarly journals The Relationship between Flower Age and Seed Production in Hatiora gaertneri and Schlumbergera truncata (Cactaceae)

HortScience ◽  
2005 ◽  
Vol 40 (7) ◽  
pp. 1988-1991
Author(s):  
Thomas H. Boyle
Keyword(s):  
Seed Production ◽  
Late Phase ◽  
Viable Seed ◽  
Flower Longevity ◽  
Degree Polynomial ◽  
Flower Opening ◽  
Production Studies ◽  
Flower Age ◽  
Viable Seeds ◽  
The Relationship

Flowers of two cacti [Hatiora gaertneri (Regel) Barthlott `Crimson Giant' and Schlumbergera truncata (Haworth) Moran `Eva'] were pollinated at different times between anthesis and senescence to determine the effect of floral age on seed production. Studies were conducted in a growth chamber (20 ± 0.5°C) to minimize temperature effects. Mean flower longevity (time from anthesis to first signs of senescence) was 4.7 days for S. truncata and 10.5 days for H. gaertneri. Stigmas of both species were receptive to pollination on the day of anthesis. The maximum number of viable seeds per pollinated flower was obtained when flowers of S. truncata and H. gaertneri were pollinated (respectively) on the second and fourth days after anthesis. For both species, the relationship between floral age and number of viable seeds per pollinated flower was described by a second-degree polynomial. The rate of pollen tube growth in the style was about 1.7 mm·h–1 for S. truncata and about 0.9 mm·h–1 for H. gaertneri. Some senesced flowers of H. gaertneri were capable of setting fruit with viable seed. Flowers of S. truncata did not set fruit when pollinated during the late phase of flower opening or after they had senesced. Senesced flowers of S. truncata failed to set fruit due to an insufficient number of pollen tubes reaching the ovary.

HEALTHINESS OF OIL PALM PLANTATION TOWARDS SUSTAINABILITY OF ENVIRONMENT

2020 ◽  
Vol 7 (1) ◽  
pp. 21
Author(s):  
Faradina Marzukhi ◽  
Nur Nadhirah Rusyda Rosnan ◽  
Md Azlin Md Said
Keyword(s):  
Oil Palm ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Satellite Image ◽  
Vegetation Indices ◽  
Soil Nutrient ◽  
Oil Palm Plantation ◽  
Sustainable Environment ◽  
Moisture Analysis ◽  
The Relationship

The aim of this study is to analyse the relationship between vegetation indices of Normalized Difference Vegetation Index (NDVI) and soil nutrient of oil palm plantation at Felcra Nasaruddin Bota in Perak for future sustainable environment. The satellite image was used and processed in the research. By Using NDVI, the vegetation index was obtained which varies from -1 to +1. Then, the soil sample and soil moisture analysis were carried in order to identify the nutrient values of Nitrogen (N), Phosphorus (P) and Potassium (K). A total of seven soil samples were acquired within the oil palm plantation area. A regression model was then made between physical condition of the oil palms and soil nutrients for determining the strength of the relationship. It is hoped that the risk map of oil palm healthiness can be produced for various applications which are related to agricultural plantation.

scholarly journals The Impact of Alkaloid-Producing Epichloë Endophyte on Forage Ryegrass Breeding: A New Zealand Perspective

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 158
Author(s):  
Colin Eady
Keyword(s):  
Seed Production ◽  
Health Issues ◽  
Abiotic Stressors ◽  
Livestock Health ◽  
The Right ◽  
The Impact ◽  
The Relationship ◽  
And Storage ◽  
Selection Of ◽  
Epichloë Endophyte

For 30 years, forage ryegrass breeding has known that the germplasm may contain a maternally inherited symbiotic Epichloë endophyte. These endophytes produce a suite of secondary alkaloid compounds, dependent upon strain. Many produce ergot and other alkaloids, which are associated with both insect deterrence and livestock health issues. The levels of alkaloids and other endophyte characteristics are influenced by strain, host germplasm, and environmental conditions. Some strains in the right host germplasm can confer an advantage over biotic and abiotic stressors, thus acting as a maternally inherited desirable ‘trait’. Through seed production, these mutualistic endophytes do not transmit into 100% of the crop seed and are less vigorous than the grass seed itself. This causes stability and longevity issues for seed production and storage should the ‘trait’ be desired in the germplasm. This makes understanding the precise nature of the relationship vitally important to the plant breeder. These Epichloë endophytes cannot be ‘bred’ in the conventional sense, as they are asexual. Instead, the breeder may modulate endophyte characteristics through selection of host germplasm, a sort of breeding by proxy. This article explores, from a forage seed company perspective, the issues that endophyte characteristics and breeding them by proxy have on ryegrass breeding, and outlines the methods used to assess the ‘trait’, and the application of these through the breeding, production, and deployment processes. Finally, this article investigates opportunities for enhancing the utilisation of alkaloid-producing endophytes within pastures, with a focus on balancing alkaloid levels to further enhance pest deterrence and improving livestock outcomes.

scholarly journals Potential and Limitations of Grasslands α-Diversity Prediction Using Fine-Scale Hyperspectral Imagery

2021 ◽  
Vol 13 (14) ◽  
pp. 2649
Author(s):  
Hafiz Ali Imran ◽  
Damiano Gianelle ◽  
Michele Scotton ◽  
Duccio Rocchini ◽  
Michele Dalponte ◽  
...  
Keyword(s):  
Species Richness ◽  
Well Being ◽  
Hyperspectral Data ◽  
Hyperspectral Images ◽  
Grassland Species ◽  
Biodiversity Indices ◽  
Grassland Ecosystems ◽  
Natural Grasslands ◽  
Α Diversity ◽  
Diversity Metrics

Plant biodiversity is an important feature of grassland ecosystems, as it is related to the provision of many ecosystem services crucial for the human economy and well-being. Given the importance of grasslands, research has been carried out in recent years on the potential to monitor them with novel remote sensing techniques. In this study, the optical diversity (also called spectral diversity) approach was adopted to check the potential of using high-resolution hyperspectral images to estimate α-diversity in grassland ecosystems. In 2018 and 2019, grassland species composition was surveyed and canopy hyperspectral data were acquired at two grassland sites: Monte Bondone (IT-MBo; species-rich semi-natural grasslands) and an experimental farm of the University of Padova, Legnaro, Padua, Italy (IT-PD; artificially established grassland plots with a species-poor mixture). The relationship between biodiversity (species richness, Shannon’s, species evenness, and Simpson’s indices) and optical diversity metrics (coefficient of variation-CV and standard deviation-SD) was not consistent across the investigated grassland plant communities. Species richness could be estimated by optical diversity metrics with an R = 0.87 at the IT-PD species-poor site. In the more complex and species-rich grasslands at IT-MBo, the estimation of biodiversity indices was more difficult and the optical diversity metrics failed to estimate biodiversity as accurately as in IT-PD probably due to the higher number of species and the strong canopy spatial heterogeneity. Therefore, the results of the study confirmed the ability of spectral proxies to detect grassland α-diversity in man-made grassland ecosystems but highlighted the limitations of the spectral diversity approach to estimate biodiversity when natural grasslands are observed. Nevertheless, at IT-MBo, the optical diversity metric SD calculated from post-processed hyperspectral images and transformed spectra showed, in the red part of the spectrum, a significant correlation (up to R = 0.56, p = 0.004) with biodiversity indices. Spatial resampling highlighted that for the IT-PD sward the optimal optical pixel size was 1 cm, while for the IT-MBo natural grassland it was 1 mm. The random pixel extraction did not improve the performance of the optical diversity metrics at both study sites. Further research is needed to fully understand the links between α-diversity and spectral and biochemical heterogeneity in complex heterogeneous ecosystems, and to assess whether the optical diversity approach can be adopted at the spatial scale to detect β-diversity. Such insights will provide more robust information on the mechanisms linking grassland diversity and optical heterogeneity.

The relationship of buried, germinating seeds to vegetation in an old-growth Colorado subalpine forest

1978 ◽  
Vol 56 (13) ◽  
pp. 1505-1509 ◽  
Author(s):  
Stephen A. Whipple
Keyword(s):  
Subalpine Forest ◽  
Forest Species ◽  
Forest Stands ◽  
Rapid Loss ◽  
Old Growth ◽  
Old Growth Forest ◽  
Viable Seeds ◽  
Relationship Of ◽  
Germinating Seeds ◽  
The Relationship

Species of buried, germinating seeds and species occurring in the vegetation are compared for two Colorado subalpine forest stands, one dry and one mesic, both over 325 years old. The total numbers of seeds found were small and the correspondence with species in the vegetation was poor. This is consistent with reports from other old-growth forests and may be accounted for by a combination of low seed input and rapid loss of viable seeds from the soil reservoir for old-growth forest species.

LA MESURE DE L’INTERFÉRENCE DU CHIENDENT DANS L’ORGE

1982 ◽  
Vol 62 (1) ◽  
pp. 183-188 ◽  
Author(s):  
R. RIOUX
Keyword(s):  
Regression Analysis ◽  
Hordeum Vulgare ◽  
Linear Relationship ◽  
Linear Relation ◽  
Shoot Density ◽  
Yield Variability ◽  
Hordeum Vulgare L ◽  
The Mean ◽  
The Relationship ◽  
Agropyron Repens

Barley (Hordeum vulgare L. ’Champlain’) was grown with quackgrass (Agropyron repens (L.) Beauv.) at various densities for 3 yr. According to the regression analysis, a linear relation is appropriate to describe the relationship between yield of barley and biomass or density of quackgrass. A greater proportion of yield variability was explained by density (64%) than by biomass (40%). Density is then a better criterion than biomass to predict yield lost in barley. The linear relationship between barley yield and the shoot density of quackgrass is estimated by the following equation: yield barley = 345.3–0.5682 dens, quackgrass. An increase of 10 shoots/m2 in the mean density of quackgrass resulted in a mean loss of 6 g/m2 in the yield of barley.

scholarly journals EVALUASI TERHADAP PERUBAHAN STATUS BEBERAPA HARA TANAH SETELAH 10 TAHUN DI BUKIT GAJABUIH PADANG

Jurnal Solum ◽  
2008 ◽  
Vol 5 (1) ◽  
pp. 23
Author(s):  
Hermansah Hermansah ◽  
Juniarti Juniarti ◽  
Utami Maya Pribadi
Keyword(s):  
Soil Nutrients ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Soil Nutrient ◽  
Nutrient Status ◽  
The Other ◽  
Experimental Plot ◽  
Soil Nutrient Status ◽  
P Content ◽  
The Relationship

This experiment is about the evaluation of characteristic alteration of soil nutrients after ten years at tropical rain forest Bukit Gajabuih Gunung Gadut Padang. This experiment was conducted from November 2006 - April 2007.  This experiment is arranged based on anova design with three treatments which was based on three great groups of land ( oxic-dystroudept (eutriccc, aquic), oxic-dystroudept (xanthic), oxic-typic-dystroudept (xanthic)).  The purpose of this experiment was to study the alteration of soil fertility characteristics  (K, Ca, Mg, Na, P and C/N) in ten years period (1995-2005) in tropical rain forest at Bukit Gajabuih Padang, to observe vegetation variety alteration, and the relationship with the land fertility characteristics.  From the experiment was found that nutrient status of the soils altered after ten years (*1995-2005).  Available P content increased about 77%, exchangeable Na and K  increased 86,04% and 53.65%, respectively.  On the other hand, exchangeable Mg and Ca decreased 3,05% and 65,88%, respectively.  Land C/N ratio decreased about 21,39%. The experimental plot had low soil pH.Key Words: tropical rain forest, soil nutrient status

scholarly journals The relationship between resource abundance and insect herbivory on islands

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256183
Author(s):  
Bora Shin ◽  
Jae-Young Lee ◽  
Nang-Hee Kim ◽  
Sei-Woong Choi
Keyword(s):  
Plant Species ◽  
Forest Cover ◽  
Food Resource ◽  
Phytophagous Insects ◽  
Feeding Guild ◽  
Resource Abundance ◽  
Variable Effect ◽  
The Relationship ◽  
External Feeding ◽  
Number Of Plant Species

We examined the relationship between resource abundance and the feeding activity of phytophagous insects on three common island plants. The aim was to investigate the correlation between phytophagous insects’ abundance and availability of food and island geography. We collected 30,835 leaves from three tree species groups (Mallotus japonicus, Prunus species, and Quercus species) on 18 islands in southwest Korea. The number of plant resources for herbivores varied: the number of leaves per shoot was the highest in Mallotus, leaf weight and the water content per leaf was significantly lower in Quercus species. External feeding was higher for Prunus and Quercus species, whereas the internal feeding type was significantly higher for Quercus species. Geography (area and distance), elevation and food resource (elevation, number of plant species, and the forest cover rate) had a variable effect on phytophagous insects feeding activities: distance and the number of plant species were more explainable to the external feeding guild. In contrast, area and forest cover were more to the internal feeding guild.

scholarly journals Effect of Pyrochar and Hydrochar on Water Evaporation in Clayey Soil under Greenhouse Cultivation

2019 ◽  
Vol 16 (14) ◽  
pp. 2580 ◽  
Author(s):  
Yang Liu ◽  
Xiaoyu Liu ◽  
Ni Ren ◽  
Yanfang Feng ◽  
Lihong Xue ◽  
...  
Keyword(s):  
Bulk Density ◽  
Clayey Soil ◽  
Soil Nutrient ◽  
Soil Bulk Density ◽  
Water Evaporation ◽  
Secondary Salinization ◽  
Inhibition Effect ◽  
New Type ◽  
Greenhouse Cultivation ◽  
The Relationship

Greenhouse cultivation consumes large volumes of freshwater, and excessive irrigation induces environmental problems, such as nutrient leaching and secondary salinization. Pyrochar (biochar from high-temperature pyrolysis) is an effective soil amendment, and researches have shown that pyrochar application could maintain soil nutrient and enhance carbon sequestration. In addition to pyrochar from pyrolysis, hydrochar from hydrothermic carbonization is considered as a new type of biochar and has the advantages of low energy consumption and a high productive rate. However, the effect of these two biochars on water evaporation in clayey soils under a greenhouse system has seldom been studied. The relationship between water evaporation and biochar properties is still unknown. Thus, in the present study, water evaporation under pyrochar and hydrochar application were recorded. Results showed that both pyrochar and hydrochar application could inhibit water evaporation in clayey soil under greenhouse cultivation. Pyrochar showed a better inhibition effect compared with hydrochar. Correlation analysis indicated that the water evaporation rate was significantly positively correlated with bulk density of biochar (p < 0.05). Overall, application of pyrochar or hydrochar could both reduce soil bulk density and inhibit soil evaporation, and be available for greenhouse cultivation. However, the inhibition effect depends on the properties of the biochar.

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