scholarly journals Herbivory and Competing Vegetation Interact as Site Limiting Factors in Maritime Forest Restoration

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 950 ◽  
Author(s):  
Emily C. Thyroff ◽  
Owen T. Burney ◽  
Douglass F. Jacobs

Herbivory and competition during the regeneration phase influence forest successional dynamics. We demonstrated the importance of using the Target Plant Concept to identify and overcome site limiting factors for subtropical maritime forest restoration associated with deer browsing and competition. Quercus virginiana Mill. (live oak) bareroot seedlings were planted into clearcuts along the US Southern Atlantic coast with different treatment combinations of herbivory control (fenced or non-fenced) against white-tailed deer (Odocoileus virginianus Zimm.) browsing and competing vegetation removal (none, one-year, or two-years). After three growing seasons, mean seedling survival was 61% with no significant treatment differences. Control of browse and vegetation interacted to facilitate growth of live oak; seedlings were significantly larger for all response parameters (diameter, height, crown width) when fenced and treated with vegetation control. Removal of vegetation improved seedling performance only in fenced plots, however, indicating a shift in pressure from herbivory to competition as the most limiting site factor when deer were excluded. After the second growing season, foliar nitrogen was greater in fenced plots than non-fenced plots and greater in two-year vegetation control subplots than non-vegetation control subplots. This result, however, was absent after the third growing season. Three years after clearcutting, there was no evidence of Q. virginiana natural regeneration in non-fenced plots. Even with artificial regeneration in non-fenced plots, Q. virginiana growth was slow, indicating that herbivory was a key limiting factor. Our findings illustrate the importance of accounting for site limiting factors and may aid in developing management prescriptions to promote semi-evergreen oak regeneration in ecosystems with high pressure from herbivory and competing vegetation.

Author(s):  
Marina Evgenievna Belyshkina ◽  
Tamara Petrovna Kobozeva ◽  
Elena Vasilevna Gureyeva

Based on long-term data, the article considers the peculiarities of growth and development of soybean varieties of the Northern ecotype depending on the conditions of the growing season and the influence of limiting factors. The need of soy plants for heat and moisture increases from seed germination to germination, then to the phases of flowering and bean formation, while their uniform distribution is important. In the absence of abnormal periods of drought or waterlogging, soybean varieties of the Northern ecotype Mature in August – early September. The purpose of the research was to determine the degree of influence of variability of agrometeorological conditions of the vegetation period in different years on the production process of soybean varieties of the Northern ecotype and to assess the possibility of their cultivation in the Ryazan and other regions of the Central district of the Non-Chernozem zone. The experiments were carried out in 2009–2019 years with varieties of soya of Northern ecotype Mahewa, Bright and the Whale. The limiting factor in some years of research in the conditions of the Ryazan region was the lack of moisture, while the biological minimum temperatures were maintained at all stages of growth and development. As a result of the analysis of the average annual temperature and precipitation data, the most favorable conditions for the cultivation of all the studied soybean varieties for seeds are formed in the Bryansk, Oryol and Ryazan regions. For Vladimir, Ivanovo, Kaluga, Moscow, Smolensk and Tula regions, the varieties Kasatka and Mageva are recommended, for Kostroma, Tver, and Yaroslavl – Kasatka. In all areas of the Central region of the Non-Chernozem zone, these varieties can be used to obtain green mass, silage and haylage.


Author(s):  
N. А. Surin ◽  
А. G. Lipshin ◽  
L. V. Plekhanova ◽  
А. А. Tikhomirov ◽  
V. V. Velichko ◽  
...  

The aim of the research was to find out the potential production characteristics of the Krasnoyarsk 12 variety wheat plants under light culture controlled conditions, as close as possible to the average light-temperature conditions of zoning (the experimental farm "Minino" of the Krasnoyarsk Territory), which in the future will allow us to determine the limiting environmental factors that affect the shortage of the crop and the decrease in its quality in the selected cultivation regions. To achieve this goal, wheat was grown by hydroponics on expanded clay under controlled environmental conditions at the intensity of photosynthetic radiation (PAR) (690±70) mmol/m2 s and at the photoperiod of 17 hours of light and 7 hours of darkness. To assess the state of plants at different stages of growth and development, we analyzed the morphometric characteristics of plants, the indicators of the state of the photosynthetic apparatus of leaves of all tiers of the main shoot of plants, plant biomass in different growth periods, indicators of CO2-gas exchange of canopies. A comparative characteristic of the yields of wheat plants of the variety Krasnoyarsk 12, grown in the conditions of light culture and in the fields of the experimental farm "MININO" in 2020, was carried out. It was established that the limiting factor of increasing the productivity of the variety in the field appeared to be the accelerated passage of individual interphase periods and the growing season as a whole in comparison with light culture. A longer growing season in light culture was primarily associated with a longer passage of the tillering phase, during which the primary tubercles were differentiated and the ear was laid. The obtained results of growing wheat plants in light culture more fully revealed the potential limits of productivity of the variety Krasnoyarsk 12. Those results were convincing evidence that the bioclimatic resources of the experimental farm "Minino" of the Krasnoyarsk Territory did not allow realizing the potential productivity of the variety and at the same time indicated the possibility of reducing the effects of limiting factors aimed at its implementation in production conditions.


Author(s):  
Felipe Vargas ◽  
Carlos A. Gonzalez-Benecke ◽  
Rafael Rubilar ◽  
Manuel Sanchez-Olate

Several studies have quantified the responses of Eucalyptus globulus plantations to weed control on its early development (2-3 years after establishment). However, long-term results of competing vegetation effects have been rarely incorporated into growth and yield models that forecast the long-term effects of reducing the intensity of competing vegetation control and its interaction with site resource availability on stem volume production close to rotation age. We compared several models predicting stand stem volume yield of Eucalyptus globulus plantations established across a water and fertility gradient growing under different intensity levels of free area of competing vegetation maintained during the first 3 years of stand development. Four sites were selected encompassing a gradient in rainfall and amount of competing vegetation. Treatments were applied at stand establishment and were monitored periodically until age 9 years. Competing vegetation control intensity levels considered 0, 5, 20, 44 and 100% weed-free cover around individual E. globulus seedlings. Maximum competing vegetation biomass production during the first growing season were 2.9, 6.5, 2.2 and 12.9 Mg ha-1, for sites ranging from low to high annual rainfall. As expected, reductions in volume yield at age 9 years were observed as competing vegetation control intensity decreased during the first growing season. A strong relationship was established between stem volume yield loss and the intensity of competing vegetation control, the amount of competing vegetation biomass produced during the first growing season and mean annual rainfall. The slope of the relationship was different among sites and was related mainly to water and light limitations. Our results, suggest that the biomass of competing vegetation (intensity of competition) affecting site resource availability, contribute to observed long-term effects on E. globulus plantations productivity. The site with the lowest mean annual rainfall showed the highest volume yield loss at age 9 years. Sites with highest rainfall showed contrasting results related to the amount of competing vegetation biomass.


Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 480
Author(s):  
Felipe Vargas ◽  
Carlos Gonzalez-Benecke ◽  
Rafael Rubilar ◽  
Manuel Sanchez-Olate

Several studies have quantified the responses of Eucalyptus globulus Labill. plantations to weed control on its early development (2–3 years after establishment). However, long-term results of competing vegetation effects have not been included into growth and yield models that incorporate treatments of competing vegetation control, and its interaction with site resource availability. In this article, we compared several models predicting stand volume yield of E. globulus plantations established across an environmental gradient, growing under different intensity levels of competing vegetation control. Four sites were selected encompassing a gradient in rainfall and amount of competing vegetation. Treatments were applied at stand establishment and were monitored periodically until age 9 years. Competing vegetation control intensity levels considered 0, 5, 20, 44, and 100% weed-free cover around individual E. globulus cuttings. Maximum competing vegetation biomass production during the first growing season were 2.9, 6.5, 2.2, and 12.9 Mg ha−1, for sites ranging from low to high annual rainfall. As expected, reductions in volume yield at age 9 years were observed as competing vegetation control intensity decreased during the first growing season. A strong relationship was established between stem volume yield loss and the intensity of competing vegetation control, the amount of competing vegetation biomass produced during the first growing season and mean annual rainfall. The slope of the relationship was different among sites and was related mainly to water and light limitations. Our results suggest that the biomass of competing vegetation (intensity of competition), affecting site resource availability, contribute to observed long-term effects on E. globulus plantations productivity. The site with the lowest mean annual rainfall showed the highest volume yield loss at age 9 years. Sites with highest rainfall showed contrasting results related to the amount of competing vegetation biomass.


Rodriguésia ◽  
2008 ◽  
Vol 59 (1) ◽  
pp. 135-150 ◽  
Author(s):  
André Mantovani ◽  
Ricardo Rios Iglesias

ABSTRACT Vegetation islands surrounded by bare sand are one of the most characteristic features of the sandy plains (restinga) of the Brazilian coastline. Abiotic conditions outside the islands are too harsh for the establishment of plants. Bromeliads are frequent both inside and at the borders of islands, but infrequent outside the islands in the restinga of Maricá. We hypothesized that the rarity of bromeliad seedlings in the restinga is due to high mortality during the seed and/or seedling stages. In this study, we assessed the potential limiting factors for germination and seedling survival of three terrestrial bromeliads Neoregelia cruenta, Aechmea nudicaulis and Vriesea neoglutinosa. Seed viability, water balance during dry-wet cycles, germination under different water potentials and the susceptibility of seedlings to high temperatures, desiccation and sand burial were analyzed. The tested seeds were nondormant, and they germinated to >70% even after exposure to 60ºC and desiccation. At temperatures > 27ºC, seeds lost water faster than imbibited it, and drywet cycles and water potentials of -0.4 MPa decreased germination. Thus, low water availability is likely limiting factor for bromeliad seed germination in the restinga of Maricá. Seedlings were extremely sensitive to high temperatures and sand burial. Shoots failed to emerge if seed depth exceeded 10 mm. We suggest that unequal temporal distribution of rainfall, low water retention capacity of the soil, and high temperatures inhibit germination and seedling establishment through water stress. Consequently, bromeliads are not likely to act as pioneer plants in the barren regions that separate restinga islands.


2021 ◽  
Vol 181 (4) ◽  
pp. 83-92
Author(s):  
I. A. Zveinek ◽  
O. N. Kovaleva

Background. The length of the growing season is a limiting factor in many regions with unstable climatic conditions. The development of ultra-early barley donors makes it possible to accelerate the breeding process aimed at producing commercial cultivars adapted to cultivation area requirements.Materials and methods. The donors Kibel, Kibel uluchshenny, Kibtsel and Kibkor were obtained through individual selection of barley forms combining earliness and productivity from the hybrid combination Belogorsky × k-15881. The experiments were carried out according to the approved guidelines. Yield components were used to calculate the index of productivity for the donors versus the reference cv. ‘Belogorsky’.Results and conclusions. Earliness is controlled in the donors by three recessive genes. The donors’ period from emergence to heading was 7–9 days shorter than that of the reference cv. ‘Belogorsky’, with a low norm of reaction, which attested to their high adaptability. The resulting barley forms were highly resistant to lodging. The donor Kibel uluchshenny in all spike yield components did not differ from the reference. The other donors were close to the reference in spike length and 1000 seed weight. The example of Kibel uluchshenny was used to demonstrate the possibility of producing barley forms combining high earliness and good productivity. The developed donors may prove useful in the breeding for earliness in the areas where the length of the growing season is a limiting factor. 


2021 ◽  
Vol 4 (2) ◽  
pp. 94-105
Author(s):  
Koko Tampubolon ◽  
Bagus Fitra Azmi ◽  
Perdana Andriano Tamba ◽  
Ayu Widya Lestari ◽  
Kamaruddin Kamaruddin ◽  
...  

Introduction: The research was aimed to obtain information on the impact of omission one test fertilization as a determination limiting factors for the growth and biomass of maize in variety Bonanza F1. Materials and Methods: The research was located in the experimental field, Faculty of Agriculture and Animal Husbandry, Universitas Tjut Nyak Dhien, Medan from December 2020 until February 2021. The research was applied by Randomized Block Design in non-factorial through fertilization of omission one test that has been converted (urea : SP-36 : KCl = 0.75 : 0.50 : 0.125 g polybag-1). The treatment of this research include P0 = non-fertilization; P1= N+P+K; P2= P+K; P3= N+K; P4= N+P using three replications. The parameters include plant height, leaf growth, total fresh weight, total dry weight, and the percentage of relative yield then processed using ANOVA and continued with DMRT at 5% ± standard error with SPSS v.20 software. Results: Informed that the omission one test technique significantly improved all the characteristics of maize in the variety Bonanza F1. The highest increase in plant height was found in the N+P of 83.65%, meanwhile, the highest leaf and biomass growth characters were found in N+P+K, ranged of 50.00 to 177.81% and 487.60 to 507.37%, respectively. It was obtained that the limiting factor for the maize growth in variety Bonanza F1 was found in the un-fertilization of nitrogen.


2016 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Mubekti Mubekti

The study is the preliminary research aiming to apply the usefulness of the GISsystem for classifying suitability of region to the agricultural mechanization. Simplebasic theory of GIS and classification of agricultural mechanization were presented.Nine physical and non-physical parameters as limiting factors were defined and aweight of each parameter was calculated in order to know how far its effect to theagricultural mechanization practice. Data coming from several types, ie: numeric,vector and remote sensing (raster) were prepared to support the process. Twoordoes consisting of five classes were employed to extract suitability classificationof each District in Jawa Barat dan Banten Province. The results show that tendistricts are classified into suitable for applying agricultural mechanization, and therest ten districts are classified into not suitable. Depending on the dynamic characterof limiting factor, suitability class would possibly change along the time. Saveralconclusions and advices for improving research are given.


2014 ◽  
Vol 90 (3) ◽  
pp. 313
Author(s):  
CLAUDIA ALVAREZ-AQUINO ◽  
GUADALUPE WILLIAMS-LINERA

La restauración del bosque tropical seco es prioritaria por ser el bosque más amenazado. En Veracruz, el bosque seco se ha reducido al 7% de su cobertura original. Nuestro objetivo fue determinar el efecto de la condición del sitio a restaurar y la estacionalidad en la supervivencia y tasa de crecimiento relativo en altura y diámetro de especies de árboles nativos. Estudiamos el desempeño de plántulas durante dos estaciones secas y dos lluviosas, y el efecto de la vegetación leñosa existente > 1 m de altura. Se trasplantaron 960 plantas: 40 individuos de seis especie (Cedrela odorata, Ceiba aesculifolia, Guazuma ulmifolia, Ipomoea wolcottiana, Luehea candida, Tabebuia rosea) en cuatro sitios abandonados. La supervivencia y la tasa de crecimiento relativo se registraron cada cuatro meses durante dos años. La mayor supervivencia se observó en sitios con mayor riqueza de especies arbóreas y la tasa de crecimiento relativo en altura estuvo positivamente correlacionada con la altura de la vegetación existente. La mayor tasa de crecimiento relativo para especies y sitios se registró durante la estación lluviosa. En el sitio con menos vegetación, el desempeño de las plántulas fue pobre y sólo Guazuma sobrevivió. Ceiba mostró la mayor supervivencia (82-90%) pero una tasa de crecimiento relativo baja; Guazuma presentó una supervivencia elevada (20-94%) y la mayor tasa de crecimiento relativo; Cedrela mostró la menor supervivencia (3-7%) y tasa de crecimiento relativo alta. Los resultados sugieren que la vegetación del sitio, la estacionalidad y las especies afectan el desempeño de las plántulas durante el establecimiento temprano. La implicación en términos de la restauración ecológica es la importancia de aprovechar la vegetación existente aunque ésta sea escasa.


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