scholarly journals Rapid revegetation by sowing seed mixtures of shrub and herbaceous species

Solid Earth ◽  
2015 ◽  
Vol 6 (2) ◽  
pp. 573-581 ◽  
Author(s):  
J. Feng ◽  
C. Zhang ◽  
T. Zhao ◽  
Q. Zhang

Abstract. Fast revegetation by means of sowing seed mixtures of shrub and herbaceous species is a measure to prevent bare soils from wind and water erosion. A field experiment was used to test the effect of species selection and the ratio of shrub to herbaceous species on vegetation formation and shrub growth. Results showed that herbaceous species hastened cover formation and maintained a high coverage for a longer period. However, the growth of shrubs was hindered. In the North China Plain or where the soil and climate are similar, the ratio of shrub to herbaceous seeds is proposed to be 6 : 4–7 : 3 (weight ratio). Among the herbaceous species tested, Festuca arundinacea Schreb. grows relatively slow, so it should be mixed with other fast-growing species in the practice of rapid revegetation, and a seeding density lower than 6 g m−2 is proposed when applied; Orychophragmus violaceus O. E. Schulz. wilts when the seeds are ripe, leading to a significant decrease of coverage, so other species with different phenology should be involved when it is applied; Viola philippica Car. is a good ground cover plant which grows fast and maintains a stable coverage from July to October, and a seeding density of 1.5 g m−2 is proposed for rapid revegetation. Herbaceous species have different traits. Three different types of herbs were found in our experiment: slow-growing stable species (F. arundinacea), fast-growing unstable species (O. violaceus) and fast-growing stable species (V. philippica). Shrubs, slow-growing stable species and fast-growing unstable species should not be used alone because they cannot cover the ground fast or they cannot maintain a long period of good coverage. A small seeding rate of fast-growing stable species should be used to ensure a fair coverage against erosion. Because natural environmental conditions are heterogeneous and stochastic, more species should be added to enhance the stability of plant community.

2015 ◽  
Vol 7 (1) ◽  
pp. 369-391
Author(s):  
J. J. Feng ◽  
C. L. Zhang ◽  
T. N. Zhao

Abstract. Fast revegetation by means of sowing seed mixture of shrub and herbaceous species is a measure to prevent bare soils from wind and water erosion. Field experiment was used to test the effect of species selection and the ratio of shrub to herbaceous species on vegetation formation and shrub growth. Results showed that herbaceous species hastened cover formation and maintained a high coverage for longer period. However, the growth of shrubs was hindered. In North China Plain or where the soil and climate are similar, the ratio of shrub to herbaceous seeds is proposed to be 6:4–7:3 (weight ratio). Among the herbaceous species tested, Festuca arundinacea Schreb. grows relatively slow so it should be mixed with other fast-growing species in the practice of rapid revegetation, and a seeding density lower than 6 g m−2 is proposed when applied; Orychophragmus violaceus O. E. Schulz. wilts when the seeds are ripe, leading to a significant decrease of coverage, so other species with different phenology should be involved when it is applied; Viola philippica Car. is a good ground cover plant, which grows fast and maintains a stable coverage form July to October, and a seeding density of 1.5 g m−2 is proposed for rapid revegetation.


Oecologia ◽  
2021 ◽  
Author(s):  
Juha Mikola ◽  
Katariina Koikkalainen ◽  
Mira Rasehorn ◽  
Tarja Silfver ◽  
Ulla Paaso ◽  
...  

AbstractFast-growing and slow-growing plant species are suggested to show integrated economics spectrums and the tradeoffs of fast growth are predicted to emerge as susceptibility to herbivory and resource competition. We tested if these predictions also hold for fast-growing and slow-growing genotypes within a silver birch, Betula pendula population. We exposed cloned saplings of 17 genotypes with slow, medium or fast height growth to reduced insect herbivory, using an insecticide, and to increasing resource competition, using naturally varying field plot grass cover. We measured shoot and root growth, ectomycorrhizal (EM) fungal production using ergosterol analysis and soil N transfer to leaves using 15N-labelled pulse of NH4+. We found that fast-growing genotypes grew on average 78% faster, produced 56% and 16% more leaf mass and ergosterol, and showed 78% higher leaf N uptake than slow-growing genotypes. The insecticide decreased leaf damage by 83% and increased shoot growth, leaf growth and leaf N uptake by 38%, 52% and 76%, without differences between the responses of fast-growing and slow-growing genotypes, whereas root mass decreased with increasing grass cover. Shoot and leaf growth of fast-growing genotypes decreased and EM fungal production of slow-growing genotypes increased with increasing grass cover. Our results suggest that fast growth is genotypically associated with higher allocation to EM fungi, better soil N capture and greater leaf production, and that the tradeoff of fast growth is sensitivity to competition, but not to insect herbivory. EM fungi may have a dual role: to support growth of fast-growing genotypes under low grass competition and to maintain growth of slow-growing genotypes under intensifying competition.


1971 ◽  
Vol 24 (4) ◽  
pp. 1115 ◽  
Author(s):  
RC Jennings

CCC and Amo.1618, at relatively high concentrations only, inhibited the growth of excised branch apices of the red alga Hypnea musciformis. Neither GA3 nor GA7 stimulated growth of the alga in the presence or absence of these compounds, and gibberellin-like material extracted from H. musciformis also failed to stimulate growth. However, both gibberellins stimulated the growth of slow-growing, but not fast-growing, branch apices of the related red alga Gracilaria verucosa. It is concluded that endogenous gibberellins may not regulate the growth of H. musciformis, but this is likely to be a peculiarity of this species and not a general phenomenon in red algae.


1985 ◽  
Vol 65 (3) ◽  
pp. 555-562 ◽  
Author(s):  
E. B. ROSLYCKY

Sensitivity to paraquat as function of growth varied considerably among 15 rhizobia from seven cross-inoculation groups and 13 agrobacteria from five different species. No relationship was evident between the sensitivity and the "fast-growing" or the "slow-growing" characteristics among the rhizobia. The agrobacteria were uniformly less sensitive. Maximum stabilized paraquat resistance induced by the adptations ranged from 200 μg paraquat∙mL−1 in Rhizobium lupini 112, to 20 000 μg paraquat∙mL−1 in Agrobacterium radiobacter R-590 and A. tumefaciens A6-K1. No relationship was found between the sensitivity and the adaptability. Identical lytic patterns with six bacteriophages confirmed the relationship between the adapted and parent cultures suggesting no genetic effect of paraquat on susceptibility to lysis. The bacteria-plant symbiont interaction, including nodulation, plant weight, vigor and color, was unaffected by the adaptations to paraquat resistance. Similarly, the adaptations exerted no effect on tumorigenicity of A. tumefaciens A6-K1. Key words: Rhizobia, agrobacteria, adaptation, herbicides, paraquat, N2-fixation


2016 ◽  
Vol 5 (2) ◽  
pp. 20-24
Author(s):  
Alexandr Zakharovych Glukhov ◽  
Lyudmila Valerievna Kharkhota ◽  
Georgy Alexandrovych Pasternak ◽  
Elena Nikolaevna Likhatskaya

We present the study results of modern dendroflora of Donetsk (a large industrial city of the south steppe zone). We have determined the species composition, analyzed the age structure of plantations, estimated the life condition of trees and shrubs. Plantations compose 76 species and 32 forms, types, sorts of trees, including 11 species and 9 sorts of the coniferous, as well as 79 species and 35 forms, sorts of shrubs, including 7 species and 19 sorts of the coniferous. Trees and shrubs belong to 78 genera, which are included into 38 families. The most represented family among the deciduous is Rosaceae Juss. - 46 species and 13 sorts, among the coniferous - Pinaceae Lindl. (9 species and 6 sorts), Cupressaceae Rich. ex Bartl. (7 species and 22 sorts). Tree species dominating in plantations are Populus bolleana Lauche (14,6% of the total number of trees), dominating shrubs are the sorts of Rosa hybrida (44,0% of the total number of shrubs). In the plantations studied we have indicated 33 species of trees and shrubs of the aboriginal fraction of local flora. Analysis of the age structure of plantations revealed that the majority of trees compose the age group of 20-29 years, the majority of shrubs - up to 10 years. Fast-growing species prevail in plantations (73% of the total number). Viability of the most part of trees of fast-growing and slow-growing species is estimated by 4 points, viability of moderate-growing species - by 6 points. The number of trees being in unsatisfactory condition (0 or 1-3 points) prevails among fast-growing species.


1995 ◽  
Vol 4 ◽  
pp. 19-22
Author(s):  
A. Anon

Pasture establishment involves considerations such as site preparation, time of sowing, seed mixtures, seed coating, method of sowing and subsequent management. The recommendations which follow relate mostly to the initial development of native tussock grassland


Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1942
Author(s):  
Giovanni Preiti ◽  
Antonio Calvi ◽  
Maurizio Romeo ◽  
Giuseppe Badagliacca ◽  
Monica Bacchi

Over two cropping seasons, 2017/18 and 2018/19, an experimental trial was conducted in a typical cereal-growing environment of the Calabrian hills (southern Italy) to study seeding rate (D) and nitrogen fertilization (N) effects on two barley F1 hybrids (Zoo and Jallon) compared to those of a traditional variety (Lutece), assessing the bio-agronomic response. Barley hybrids, gradually introduced into the principal European countries starting in 2010 as winter forage, currently represent a significant part of the EU internal market. Productive performance was evaluated as grain yield for feed and total biomass for silage and/or biogas production. Research results pointed out the greater performance of barley hybrids compared to conventional varieties in terms of both grain and biomass production. On average, barley hybrids vigour mainly manifested itself through a high tillering and a greater number of ears m−2 compared to those of the conventional variety (+24 and +23%, respectively). Furthermore, barley hybrids were characterized by a greater 1000-kernel weight and hectolitre weight than those of the Lutece variety (conventional variety). A significant increase in grain production was observed, increasing density from D150 to D225 rates (+35% and +33%, respectively) which was followed by a decrease in production shifting from D225 to D300 doses. A significant increase in biomass production was as well highlighted for the two hybrids, shifting from D150 to D225 rates (+26% and +27%, respectively). The applied nitrogen dose highlighted a different behaviour between the hybrids and the conventional variety; in particular, the lowest nitrogen dose (N80) negatively influenced the Lutece variety both in terms of grain and biomass production (−9% and −16%, respectively) while the hybrids showed the best agronomic response even at the lowest dose. On average, with the N80 dose, grain yield of Zoo and Jallon was greater than 20% and 16%, while with the N120 dose grain yield was 9% and 7%, respectively. A similar behaviour was found for biomass yield. It should therefore be emphasized that barley hybrids possess high yielding capacities and that such higher grain production can be achieved in a Mediterranean environment by using a lower seed rate (approximately −25%) and a reduced nitrogen dose (approximately −33%) compared with those commonly applied to conventional varieties.


2006 ◽  
Vol 61 (9-10) ◽  
pp. 619-624 ◽  
Author(s):  
Xinkun Wang ◽  
Yinghua Huang ◽  
Andrew J. Mort ◽  
Yuhong Zeng ◽  
Charles G. Tauer ◽  
...  

AbstractNeedles from 17 different Taxus x media cultivars, belonging to 4 groups showing different growth characteristics, were analyzed using high performance liquid chromatography for their content of 10-deacetylbaccatin III, baccatin III, cephalomannine and paclitaxel (Taxol®). The 4 Taxus x media cultivar groups were: 1.) medium to fast growing and upright form; 2.) slow growing and upright form; 3.) fast growing and spreading form; and 4.) slow growing and spreading form. The purpose of this study was to identify yew cultivars of fast growth rate, upright growth and high taxane content in their needles. The highest content of paclitaxel was found in ‘Coleana’ of group 1 (378 μg/g of the extracted dry weight). Three cultivars in group 1, ‘Coleana’, ‘Stovekenii’ and ‘Hicksii’, make good candidates for taxane extraction because of their high paclitaxel and 10-deacetylbaccatin III content, fast biomass accumulation and upright growing form. They are also good starting materials to develop alternative methods for the production of paclitaxel and its analogous compounds through modern biotechnology approaches.


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