The Effects of Canopy Gaps on Seedling Emergence and Growth of Two Deciduous Broad-leaved Species (Cornus controversa and Prunus grayana) in a Cryptomeria japonica Plantations

2001 ◽  
Vol 6 (4) ◽  
pp. 303-305 ◽  
Author(s):  
Jiro Kodani
Keyword(s):  
Cryptomeria Japonica ◽  
Seedling Emergence ◽  
Canopy Gaps ◽  
Cornus Controversa ◽  
Broad Leaved Species ◽  
Prunus Grayana

scholarly journals Depression of the soil arbuscular mycorrhizal fungal community by the canopy gaps in a Japanese cedar (Cryptomeria japonica) plantation on Lushan Mountain, subtropical China

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10905
Author(s):  
Guiwu Zou ◽  
Yuanqiu Liu ◽  
Fanqian Kong ◽  
Liqin Liao ◽  
Guanghua Deng ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Cryptomeria Japonica ◽  
Soil Nutrient ◽  
Japanese Cedar ◽  
Arbuscular Mycorrhizal ◽  
Nutrient Content ◽  
Canopy Gaps ◽  
Long Term Effects ◽  
Subtropical China ◽  
Lushan Mountain

Both canopy gaps (CG) and arbuscular mycorrhizal fungi (AMF) play key roles in seedling establishment and increasing species diversity in forests. The response of AMF to canopy gaps is poorly understood. To assess the long-term effects of canopy gaps on soil AMF community, we sampled soil from plots in a 50-year Cryptomeria japonica (L.f.) D. Don. plantation, located in Lushan Mountain, subtropical China. We analyzed the AMF community, identified through 454 pyrosequencing, in soil and edaphic characteristics. Both richness and diversity of AMF in CG decreased significantly compared to the closed canopy (CC). The differences of the AMF community composition between CG and CC was also significant. The sharp response of the AMF community appears to be largely driven by vegetation transformation. Soil nutrient content also influenced some taxa, e.g., the low availability of phosphorus increased the abundance of Acaulospora. These results demonstrated that the formation of canopy gaps can depress AMF richness and alter the AMF community, which supported the plant investment hypothesis and accentuated the vital role of AMF–plant symbioses in forest management.

Ecological aspects of weed control in cotton in the Ord River valley, W.A. 2. The effect of soil depth on emergence of weed seedlings

1969 ◽  
Vol 9 (36) ◽  
pp. 19
Author(s):  
Rijn PJ van
Keyword(s):  
Seed Weight ◽  
Soil Depth ◽  
Seedling Emergence ◽  
River Valley ◽  
Irrigation Area ◽  
Emergence Pattern ◽  
Irrigated Area ◽  
Ecological Aspects ◽  
Practical Implications ◽  
Broad Leaved Species

A study was made of the emergence from various soil depths of cotton, six grasses and six broad-leaved weeds commonly occurring in the irrigated area of the Ord River valley, W.A. The experiments were conducted in a glasshouse under temperatures fluctuating between 20� and 35�C, under conditions of adequate aeration and soil water in Cununurra clay, the main soil type of the Ord irrigation area. Seedling emergence was inversely related to seed depth, and, in general, the ability of seeds to emerge from various soil depths was positively associated with the average seed weight of the species. Of the grasses, only Echinochloa colonum and Iseilema vaginiflorum emerged from depths exceeding 3 inches. The maximum depths from which broad-leaved species emerged varied from 3 to 7 inches, depending on the species. The emergence pattern of cotton was almost identical with that of Hibiscus ficulneus and Operculina turpethum, but cotton and Operculina were the only species to emerge from a depth of 7 inches and then only in small numbers. The practical implications of these findings on depth of cultivation and herbicide placement are discussed.

scholarly journals Forest canopy gaps offer a window into the future The case of subtropical coastal forests within an urban matrix in South Africa

2021 ◽  
Vol 30 (1) ◽  
pp. e003
Author(s):  
Astika Bhugeloo ◽  
Syd Ramdhani ◽  
Kabir Peerbhay ◽  
Olivier Kambol Kambaj ◽  
Sershen
Keyword(s):  
South Africa ◽  
Species Richness ◽  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Seedling Emergence ◽  
Canopy Gaps ◽  
Coastal Forests ◽  
Disturbed Forest ◽  
Primary Forests

Aim of the study: Alien and indigenous species emergence patterns within canopy gaps in urban subtropical forests are poorly understood. This study compared canopy gap floristics in relation to abiotic and physical characteristics across three subtropical urban forests differing in disturbance history.Area of study: Three Northern Coastal Forests of varying disturbance histories found in coastal subtropical urban KwaZulu-Natal (KZN), South Africa (SA).Materials and methods: Closed canopy ( n = 15 quadrats per forest ) and four gaps from three size classes (‘small’ < 25 m2, ‘medium’ 25 - 45 m2; ‘large’ > 45 m2) were surveyed for each forest using classical vegetation sampling techniques. Soil moisture content and air temperature were measured within each gap.Main results: Cumulatively all forests hosted 198 species. Species richness was highest in the primary highly disturbed forest followed by the primary least disturbed forest and lowest in the transitional highly disturbed forest. Alien taxa cover within gaps was correlated with higher indigenous seedling emergence in the primary forests. Species richness was positively correlated with gap size and soil moisture content, and negatively correlated with air temperature.Research highlights: Gap floristic patterns are influenced by size, abiotic factors, disturbance and forest successional status. Alien taxa may facilitate indigenous seedling emergence within gaps in primary forests. Floristic, abiotic and physical characteristics of canopy gaps should be monitored within urban forests as they can influence gap infilling regarding species composition and rate. This can inform management strategies including species reintroduction and enrichment planting.

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

Seedling emergence of Lupinus diffusus in response to abrasion in an electric seed scarifier

2019 ◽  
Vol 20 (1) ◽  
pp. 14-24
Author(s):  
Gabriel Campbell-Martínez ◽  
Mack Thetford ◽  
Deborah L Miller ◽  
Héctor E Pérez
Keyword(s):  
Seedling Emergence

Effects of salinity on seedling emergence and early seedling growth of Irvingia gabonensis (Irvingiaceae)

2017 ◽  
Vol 45 (2) ◽  
pp. 282-295
Author(s):  
R. Vihotogbé ◽  
C. Watson ◽  
R. Glèlè Kakaï ◽  
F. Wichern ◽  
B. Sinsin ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Seedling Emergence ◽  
Early Seedling Growth ◽  
Early Seedling ◽  
Irvingia Gabonensis

Drought stress and osmo-priming effects on physiological and biochemical characteristics of Ocimum basilicum

2016 ◽  
Vol 6 (1) ◽  
pp. 905-913
Author(s):  
Bahram Majd Nassiry ◽  
Neda Mohammadi
Keyword(s):  
Drought Stress ◽  
Total Protein ◽  
Catalase Activity ◽  
Seedling Emergence ◽  
Seed Priming ◽  
Ocimum Basilicum ◽  
Field Development ◽  
Physiological And Biochemical Characteristics ◽  
Germination Characteristics ◽  
And Control

    One of the effects of reducing water content on soil is reduction of growth and development of seedlings and variation of field development. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stresses. The objectives of this research were to evaluate the effects of osmo-priming on germination characteristics and changes of proline, protein and catalase activity of Ocimum basilicum seeds. Results showed that drought stress reduced the germination characteristics and drought stress in -8 bar was the critical stress.  Priming treatments were include KNO3, PEG and NaCl by 0, -4 and -8 bar concentrations. The seeds were primed with those materials for 8 and 16 hours. The highest germination characteristics were obtained from nitrate potassium in -8 bar for 16 hours priming. Therefore the best seed treatment under drought stress during germination was obtained from the osmo-primed with -8 bar nitrate potassium for 16 hours. The drought stress increased proline and catalase activity but reduced total protein. Priming treatment increases proline, total protein and catalase activity under drought and control conditions. It is concluded that priming results in improvement in germination components of Ocimum basilicum in drought stress conditions and increases the resistance to drought stress with improvement of proline, protein and catalase activity in germination phase.

EFFECT OF TEMPORARY COVERING ON EARLY POTATO YIELD IN THE CONDITIONS OF THE MOSCOW REGION

2020 ◽  
pp. 31-38
Author(s):  
MARINA E. DIYKANOVA ◽  
◽  
ALEKSANDR G. LEVSHIN ◽  
IRINA N. GASPARYAN ◽  
NATALIA F. DENISKINA ◽  
...  
Keyword(s):  
Seedling Emergence ◽  
Maximum Yield ◽  
Moscow Region ◽  
Cold Weather ◽  
Test Plot ◽  
Early Potato ◽  
Emergence Period ◽  
Potato Varieties ◽  
Russian State ◽  
Covering Material

In the Moscoww region, frosts are quite probable to return until the fi rst decade of June. To protect potatoes from the returning cold weather, it is possible to use a temporary covering material in the “planting – seedling emergence” period. The authors have studied the use of covering materials on early potato varieties of Udacha, Zhukovsky early, Red Scarlet, Snegir’, and Meteor. Studies have been conducted on the test plot of the Vegetable Growing Department of Russian State Agrarian University – Moscow Timiryazev Agricultural Academy in 2017-2019. Non-woven white and black material of the same density of 17 g/m2 was used for covering. No covering was used in the check variant. The cultivation technology was standard,it included tillage (plowing, spring tillage, and cutting ridges before planting), as well as plant care (inter-row cultivation and hilling-up). Planting was carried out with a single-row potato planter. The earliest emergence of seedlings was observed under white covering material with a diff erence of 5-6 days in relation to the check variant. In the variant with a black covering material, the diff erence averaged 3-4 days. Due to covering, planting was carried out earlier than expected and the crop was formed by July 15. The interphase period between potato planting and seddling emergence decreased, while that from seddling emergence to harvesting increased, consequently, the yield increased by 11.6…14.7%. The maximum yield was obtained with the Red Scarlet variety using the white covering material, the minimum – in the check variant without covering. The same trend is typical for other varieties. It has been established that covering with any material has a positive eff ect on the duration of the potato growing season and the yield by increasing the period of tuberization. Covering allows getting early potato varieties 2 weeks earlier in the Moscow region.

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