Effects of heathland management on seedling recruitment of common juniper (Juniperus communis)

Background and aims – Common juniper (Juniperus communis L.) is one of the most widespread woody species on the planet. Over recent decades, however, common juniper populations are decreasing in size and number in different regions. Lack of recruitment, caused by extremely low seed viability and the absence of suitable microsites for recruitment, is the key reason for this decline. For successful germination, the seeds need gaps in the existing vegetation and a soil with a relatively high base saturation. The aim of this study was therefore to assess how management actions such as sod cutting, rotavation and liming (alone or in various combinations) influence soil characteristics, seed germination and seedling survival of common juniper.Methods – We installed a sowing experiment across 104 1-m2 plots in four different sites in Belgium and the Netherlands using treatments with different combinations of fencing, sod cutting, rotavation, litter addition and liming. We determined how these treatments affected soil characteristics and how they influenced seed germination and seedling survival.Key results and conclusions – Across the whole experiment, germination rates of juniper seeds were very low (almost always < 1%). Our results confirm that bare ground promotes the germination of juniper seeds. Secondly, higher silt and lutum (clay) proportions in the soil and higher soil organic matter content seemed to have a positive impact on recruitment, possibly due to drought reduction. Management actions that negatively affect those soil characteristics, such as deep sod cutting, should thus be avoided in heathlands on sandy soils. Our results reveal a complex relationship between seedling recruitment success, soil conditions and management of common juniper populations. Overall, combinations of fencing, (superficial) sod cutting and liming or rotavation were most successful.

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Spatial decision support for crop structure adjustment – a case study for selection of potential areas for sorghum (Sorghum bicolor (L.) Moench) production

Agrokémia és Talajtan ◽

10.1556/0088.2018.67.1.4 ◽

2018 ◽

Vol 67 (1) ◽

pp. 49-59

Author(s):

János Jóvér ◽

Elza Kovács ◽

Péter Riczu ◽

János Tamás ◽

Lajos Blaskó

Keyword(s):

Sorghum Bicolor ◽

Soil Type ◽

Extreme Values ◽

Organic Matter Content ◽

Soil Characteristics ◽

Soil Conditions ◽

Climatic Data ◽

Great Hungarian Plain ◽

Structure Adjustment ◽

Hungarian Plain

One option for adaptation to climate change is to grow a wider variety of plant species. Sorghum (Sorghum bicolor (L.) Moench) is known to tolerate unfavourable environmental conditions, so it may be feasible to grow it on areas with extreme conditions to replace other species such as maize. Nowadays, spatial decision supporting systems primarily support the crop production process rather than crop structure adjustment. In this study, potential sorghum production sites in the Great Hungarian Plain were selected based on soil characteristics including genetic soil type, parent material, physical soil type, clay composition, water management, pH, organic matter content, topsoil thickness and fertility, as well as climatic data, particularly precipitation. For all the parameters the aim was to find the extreme values at which sorghum, which is less sensitive than maize, may still give an acceptable yield. By combining map layers of soil characteristics, it could be concluded that although the soil is suitable for sorghum on 40.46% of the Great Hungarian Plain, maize is generally a better choice economically. On the other hand, the soil conditions on 0.65% of the land are still suitable for sorghum but unfavourable for maize. As regards the precipitation demand of sorghum, May is the critical period; on 698,968 ha the precipitation required for germination was only recorded once in the period 1991-2010, so these areas cannot be considererd for sorghum. As a consequence, in an alternative crop rotation system sorghum could be competitive with maize, but both the soil and climate conditions and the demands of the crop need to be assessed. The lack of precipitation in critical phenophases significantly decreases the area where maize can survive. Sorghum, however, may produce an acceptable yield, as it is a drought-resistant species.

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Impacts of soil moisture level and organic matter content on growth of two Juncus species and Poa pratensis grown under acid soil conditions

Weed Research ◽

10.1111/wre.12387 ◽

2019 ◽

Vol 59 (6) ◽

pp. 490-500

Author(s):

W Kaczmarek‐Derda ◽

M Helgheim ◽

J Netland ◽

H Riley ◽

K Wærnhus ◽

...

Keyword(s):

Organic Matter ◽

Soil Moisture ◽

Poa Pratensis ◽

Acid Soil ◽

Organic Matter Content ◽

Matter Content ◽

Moisture Level ◽

Soil Conditions ◽

Soil Moisture Level

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Using Microwave Soil Heating to Inhibit Invasive Species Seed Germination

Invasive Plant Science and Management ◽

10.1017/inp.2017.29 ◽

2017 ◽

Vol 10 (3) ◽

pp. 262-270 ◽

Cited By ~ 7

Author(s):

Mélissa De Wilde ◽

Elise Buisson ◽

Nicole Yavercovski ◽

Loïc Willm ◽

Livia Bieder ◽

...

Keyword(s):

Invasive Species ◽

Soil Moisture ◽

Seed Germination ◽

Invasive Plant ◽

Organic Matter Content ◽

Seed Viability ◽

Germination Percentage ◽

Matter Content ◽

Burial Depth ◽

Experimental Conditions

Successful invasive plant eradication is rare, because the methods used target the adult stage, not taking into account the development capacity of a large seedbank. Heating by microwave was considered, because it offers a means to quickly reach the temperature required for loss of seed viability and inhibition of germination. Previous results were not encouraging, because homogeneous and deep-wave penetration was not achieved, and the various parameters that can affect treatment effectiveness were incompletely addressed. This study aimed to determine, under experimental conditions, the best microwave treatment to inhibit invasive species seed germination in terms of power (2, 4, 6 kW) and duration (2, 4, 8 min) of treatments and depending on soil moisture (10%, 13%, 20%, 30%) and seed burial depth (2, 12 cm). Three invasive species were tested: Bohemian knotweed, giant goldenrod, and jimsonweed. The most effective treatments required relatively high power and duration (2kW8min, 4kW4min, 6kW2min, and 6kW4min; 4kW8min and 6kW8min were not tested for technical reasons), and their effectiveness diminished with increasing soil moisture with germination percentage between 0% and 2% for the lowest soil moisture, 0% and 56% for intermediate soil moisture, and 27% and 68% in control treatments. For the highest soil moisture, only 2kW8min and 4kW4min reduced germination percentage between 2% and 19%. Occasionally, germination of seeds located at the 12-cm depth was more strongly affected. Giant goldenrod seeds were the most sensitive, probably due to their small size. Results are promising and justify further experiments before developing a field microwave device to treat large volumes of soil infested by invasive seed efficiently and with reasonable energy requirements. Other types of soil, in terms of texture and organic matter content, should be tested in future experiments, because these factors influence soil water content and, consequently, microwave heating.

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RESPON IKAN KARANG PADA AREA APARTEMEN IKAN DI PERAIRAN TOBOLOLO DAN GAMALAMA KOTA TERNATE

Coastal and Ocean Journal (COJ) ◽

10.29244/coj.1.1.1-6 ◽

2017 ◽

Vol 1 (1) ◽

pp. 1-6

Author(s):

Aditiyawan Ahmad

Keyword(s):

Positive Impact ◽

Management Actions ◽

Coral Fish ◽

Number Of Individuals ◽

Total Species

Fish apartment is a management actions to maintain the presence of coral fish that serves as a new habitat well as shelter and spawning. The number of fish apartment at each location is 20 units. The present study aimed at assessment the response of coral fish to the fish apartment based on the species and number of individuals coral fish. Total species found in the area of fish apartment as much as 7 families and 9 species with a total of 241 individual coral fish in the Tobololo, while 12 families and 23 species with a total of 567 individual. Moreover, the juvenile of coral fish is not identified with a size of 2-3 cm, the number of individuals in Tobololo 154 and 275 in Gamalama. The response of coral fish positively to the fish apartment evidenced by an increase in abundance and the percentage of the number and types of coral fish. So that management action with fish apartment approach provides a positive impact on the presence of coral fish as a new habitat and supports the corals juvenile.

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The Diversification and Intensification of Crop Rotations under No-Till Promote Earthworm Abundance and Biomass

Agronomy ◽

10.3390/agronomy10070919 ◽

2020 ◽

Vol 10 (7) ◽

pp. 919

Author(s):

María Pía Rodríguez ◽

Anahí Domínguez ◽

Melisa Moreira Ferroni ◽

Luis Gabriel Wall ◽

José Camilo Bedano

Keyword(s):

Species Composition ◽

Crop Production ◽

Positive Impact ◽

Organic Matter Content ◽

Taxonomic Composition ◽

Matter Content ◽

Crop Rotations ◽

Subtle Change ◽

No Till ◽

Novel Approach

The diversification and intensification of crop rotations (DICR) in no-till systems is a novel approach that aims to increase crop production, together with decreasing environmental impact. Our objective was to analyze the effect of different levels of DICR on the abundance, biomass, and species composition of earthworm communities in Argentinean Pampas. We studied three levels of DICR—typical rotation (TY), high intensification with grass (HG), and with legume (HL); along with three references—natural grassland (NG), pasture (PA), and an agricultural external reference (ER). The NG had the highest earthworm abundance. Among the DICR treatments, abundance and biomass were higher in HL than in HG and, in both, these were higher than in TY. The NG and PA had a distinctive taxonomic composition and higher species richness. Instead, the DICR treatments had a similar richness and species composition. Earthworm abundance and biomass were positively related to rotation intensity and legume proportion indices, carbon input, and particulate organic matter content. The application of DICR for four years, mainly with legumes, favors the development of earthworm populations. This means that a subtle change in management, as DICR, can have a positive impact on earthworms, and thus on earthworm-mediated ecosystem services, which are important for crop production.

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Organic Matter Clogging Results in Undeveloped Hardpan and Soil Mineral Leakage in the Rice Terraces in the Philippine Cordilleras

Water ◽

10.3390/w12113158 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3158

Author(s):

Tomoyo Kurozumi ◽

Yasushi Mori ◽

Hiroaki Somura ◽

Milagros O-How

Keyword(s):

Organic Matter ◽

Soil Analysis ◽

Influencing Factor ◽

Soil Layer ◽

Organic Matter Content ◽

Matter Content ◽

Water Infiltration ◽

Soil Conditions ◽

Infiltration Process ◽

Soil Nutrition

Rice terraces in Cordillera, Philippines, a world cultural heritage site, are threatened by the risk of collapse. It is crucial to manage these rice terraces for their conservation, while simultaneously practicing traditional farming. We examined the soil environment and investigated its effects on rice terrace conservation, by focusing on the hardpan condition; infiltration process, which is related to the collapse of rice terraces; and soil nutrition conditions in these sites. Field survey and soil analysis revealed that in areas where the hardpan was not sufficiently developed and water infiltration was effectively suppressed, organic matter content was significantly high, suggesting organic matter clogging. In these rice terraces, the amounts of P, K, Ca, and Mn were significantly low, showing the mineral leaching under reductive soil conditions. Therefore, hardpan formation, rather than organic matter clogging, is essential for the suppression of infiltration and prevention of potential terrace collapse. Because hardpan formation or organic matter clogging cannot be identified from the surface of flooded rice paddies, it is difficult to identify the influencing factor. Thus, we suggest that the hard soil layer should be checked before the planting season and drainage is allowed after the cropping season in the rainy season.

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Comparison of the plant growth-promotion performance of a consortium of Bacilli inoculated as endospores or as vegetative cells

FEMS Microbiology Ecology ◽

10.1093/femsec/fiz147 ◽

2019 ◽

Vol 95 (11) ◽

Cited By ~ 4

Author(s):

Isha Hashmi ◽

Christophe Paul ◽

Andrej Al-Dourobi ◽

Frederic Sandoz ◽

Priscilla Deschamps ◽

...

Keyword(s):

Seed Germination ◽

Plant Growth ◽

Positive Impact ◽

Growth Promotion ◽

Soil Microbial Communities ◽

Vegetative Cells ◽

Single Strain ◽

Positive Effects ◽

Pot Experiments

ABSTRACT The effect of three plant growth-promoting Bacillus strains inoculated either alone or as a consortium was tested on oat (Avena sativa) growth. The bioinoculants were applied as vegetative cells or endospores at low cell densities on the seeds and their effect was tested in sterile in vitro conditions, pot experiments, and a field trial. The in vitro seed germination assay showed that both individual bacterial inocula and bacterial consortia had positive effects on seed germination. Greenhouse pot experiments with sterile and non-sterile soil showed that consortia increased the total dry biomass of oat plants as compared to single strain inoculation and uninoculated controls. However, the positive impact on plant growth was less prominent when the bioinoculated strains had to compete with native soil microbes. Finally, the field experiment demonstrated that the consortium of vegetative cells was more efficient in promoting oat growth than the endospore consortium and the uninoculated control. Moreover, both consortia successfully colonized the roots and the rhizosphere of oat plants, without modifying the overall structure of the autochthonous soil microbial communities.

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JUNIPERUS COMMUNIS, COMMON JUNIPER

The Trees of Great Britain and Ireland ◽

10.1017/cbo9781107252837.020 ◽

2014 ◽

pp. 1400-1408

Author(s):

Henry John Elwes ◽

Augustine Henry

Keyword(s):

Juniperus Communis ◽

Common Juniper

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Environmental filters and seedling recruitment on a coastal dune in subarctic Quebec (Canada)

Canadian Journal of Botany ◽

10.1139/b96-181 ◽

1996 ◽

Vol 74 (9) ◽

pp. 1507-1513 ◽

Cited By ~ 36

Author(s):

Gilles Houle

Keyword(s):

Seed Germination ◽

Spatial Pattern ◽

Seedling Establishment ◽

Seedling Recruitment ◽

Salt Spray ◽

Spatial Segregation ◽

Coastal Dune ◽

Seedling Mortality ◽

Environmental Filters ◽

Dune System

One important factor that often determines the presence of a plant species on a site is propagule availability. Afterwards, abiotic and biotic factors act as a series of filters operating sequentially from the seed to the adult stage, determining the pattern of recruitment. By comparing the spatial pattern of emerging seedlings to those of seed availability and of surviving seedlings, one can determine the relative importance of the environmental filters acting on the seed germination and the seedling establishment phases. On a coastal dune system in subarctic Quebec (Canada), sand accumulation, salt spray, and substrate physicochemistry, all affecting microsite quality for seeds and seedlings, vary along a short topographical gradient. My goal was to determine whether or not conditions changing along this gradient differentially affect the initial stages of population recruitment of two perennial herbaceous species for which adults are segregated along the gradient: Honckenya peploides and Elymus mollis. The spatial pattern of seeds in the seed bank and that of emerging seedlings were not related to one another for either Honckenya or Elymus. However, patterns of surviving seedlings were spatially correlated with those of emerging seedlings. Seed and seedling mortality were not density dependent; they were both spatially variable, although not clinal. These results suggest that the environmental filters acting on the germination stage are those that determine the spatial patterns of recruitment. Spatial segregation along the flank of the foredune between adults of the two species studied thus seems to be maintained in part (and maybe reinforced) by low seed mobility, or low seed retention, and the availability of suitable microsites for seed germination. Population progression towards the upper beach seems to depend mostly on seedling establishment for Honckenya but on clonal growth for Elymus. Keywords: Elymus mollis, Honckenya peploides, Hudson Bay, partial Mantel test, spatial segregation, Whapmagoostui-Kuujjuaraapik.

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