Response of red alder (Alnus rubra) seedlings to a woolly alder sawfly (Eriocampa ovata) outbreak

1998 ◽  
Vol 28 (4) ◽  
pp. 591-595 ◽  
Author(s):  
John H Markham ◽  
C P Chanway
Keyword(s):  
Growth Rate ◽  
Positive Relationship ◽  
Negative Relationship ◽  
Growing Season ◽  
High Elevation ◽  
Alnus Rubra ◽  
Herbivore Damage ◽  
Red Alder ◽  
Relative Growth ◽  
High Degree

We monitored the effect of an outbreak of Eriocampa ovata L.on experimental Alnus rubra Bong. seedlings during the year of the outbreak (1993) and the following growing season. Seedlings planted on low-elevation sites had significantly more of their leaves damaged (>50% per tree) than plants on high-elevation sites (<25% per tree), with significant differences between low-elevation sites during the year of the outbreak. There was a positive relationship between the amount of herbivore damage and plant relative growth rate early in the growing season and a negative relationship by August. This suggests that the sawflies attacked the largest and fastest growing plants, reducing their growth by midsummer. Plants with the highest degree of herbivore damage were the largest by the end of the growing season with no effects on plant growth the following year. Leaves from plants that had previously been defoliated were less palatable to E. ovata in 1994, but plants with a high degree of herbivore damage in 1994 were likely plants that had a high degree of damage in 1993.

scholarly journals Seed mass effects on germination and growth of diverse European Scots pine populations

1994 ◽  
Vol 24 (2) ◽  
pp. 306-320 ◽  
Author(s):  
P.B. Reich ◽  
J. Oleksyn ◽  
M.G. Tjoelker
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Scots Pine ◽  
Field Experiments ◽  
Seed Mass ◽  
Growing Season ◽  
Turkish Population ◽  
Dry Mass ◽  
Relative Growth ◽  
Mass Effects

Seedlings of 24 European Scots pine (Pinussylvestris L.) populations were grown in controlled environment chambers under simulated photoperiodic conditions of 50 and 60°N latitude to evaluate the effect of seed mass on germination and seedling growth characteristics. Seeds of each population were classified into 1-mg mass classes, and the four classes per population with the highest frequencies were used. Photoperiod had minimal influence on seed mass effects. Overall, seed mass was positively related to the number of cotyledons and hypocotyl height. Populations differed significantly in seed mass effect on biomass. In northern populations (55–61°N), dry mass at the end of the first growing season was little affected by seed mass. However, dry mass in 9 of 15 central populations (54–48°N) and all southern (<45°N) populations correlated positively with seed mass. Relative growth rate was not related to seed mass within or across populations, and thus early growth is largely determined by seed mass. Relative growth rate also did not differ among populations, except for a geographically isolated Turkish population with the highest seed mass and lowest relative growth rate. After one growing season, height was positively correlated (r2 > 0.6) with seed mass in 15 populations. To check the duration of seed mass effects, height growth of 1- to 7-year-old field experiments established with the same seed lots were compared. Seed mass effects on height were strongest for 1-year-old seedlings and declined or disappeared by the age of 5–7 years among central and southern populations, but remained stable over that time in northern populations.

Growth and Development of Organic Arsenical-Susceptible and -Resistant Common Cocklebur (Xanthium strumarium) Biotypes Under Noncompetitive Conditions

1994 ◽  
Vol 8 (1) ◽  
pp. 154-158 ◽  
Author(s):  
William E. Haigler ◽  
Billy J. Gossett ◽  
James R. Harris ◽  
Joe E. Toler
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Plant Height ◽  
Growth And Development ◽  
Reproductive Potential ◽  
Dry Weight ◽  
Growing Season ◽  
Xanthium Strumarium ◽  
Relative Growth ◽  
Growth Development

The growth, development, and reproductive potential of several populations of organic arsenical-susceptible (S) and -resistant (R) common cocklebur biotypes were compared under noncompetitive field conditions. Plant height, leaf area, aboveground dry weights, and relative growth rate (RGR) were measured periodically during the growing season. Days to flowering, bur dry weight, and number of burs per plant were also recorded. Arsenical S- and R-biotypes were similar in all measured parameters of growth, development, and reproductive potential. Populations within each biotype varied occasionally in plant height, leaf area, aboveground dry weights, and reproductive potential.

THE WING LENGTH OF SWELTSA REVELSTOKA (PLECOPTERA: CHLOROPERLIDAE)

1985 ◽  
Vol 117 (2) ◽  
pp. 233-239 ◽  
Author(s):  
D.B. Donald
Keyword(s):  
Body Size ◽  
Significant Relationship ◽  
Positive Relationship ◽  
Wing Length ◽  
Negative Relationship ◽  
Head Capsule ◽  
High Elevation ◽  
Glacial Ice ◽  
Significant Negative Relationship ◽  
Stream Size

AbstractFunctional wing length (wing length/head-capsule width) of female Sweltsa revelstoka (Jewett) from streams was measured for 19 sites that have been free of Wisconsin glacial ice for about 15 000 years and possibly longer, and from 23 sites that have been ice free for about 10 000 years. At the former sites brachypterous populations were common and there was a significant negative relationship between functional wing length and elevation, and a positive relationship between functional wing length and stream size. In the area that deglaciated more recently, populations were not or only slightly brachypterous and there was no significant relationship between wing length and elevation or between wing length and stream size. Functional wing length was not related to body size. These analyses indicate that the brachypterous condition is probably genotypic in origin. I suggest that streams were colonized by macropterous forms shortly after deglaciation, and that brachyptery takes several millennia to develop at small, high-elevation streams.

scholarly journals Leaf and Stem Traits are Linked to Liana Growth Rate in a Subtropical Cloud Forest

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1120
Author(s):  
Xiao-Long Bai ◽  
Yun-Bing Zhang ◽  
Qi Liu ◽  
Yang-Si-Ding Wang ◽  
Da Yang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Cloud Forest ◽  
High Elevation ◽  
Growth Patterns ◽  
Relative Growth ◽  
Leaf Vein ◽  
Vein Density ◽  
Leaf Vein Density

There is accumulating evidence that the abundance and biomass of lianas are increasing with global climate change in the Neotropics. However, our knowledge of growth–trait relationships among lianas is surprisingly rare. Here, we monitored the relative growth rate of 2860 individuals from seven deciduous and four evergreen liana species in a 20 ha subtropical cloud forest dynamics plot at high elevation (2472–2628 m a.s.l.) in southwest China. We linked the relative growth rate of lianas with nine leaf traits associated with leaf morphology, nutrient concentrations, and water hydraulic capacity as indicated by leaf vein density, and five stem wood traits related to stem water transport capacity and wood density. Our results showed that deciduous lianas have higher relative growth rates than their evergreen counterparts. Across all lianas studied, the relative growth rate was positively correlated with the leaf area and specific leaf area, but negatively correlated with leaf dry matter content. The relative growth rate of lianas was strongly correlated with nitrogen concentration after excluding the legume liana species. The relative growth rate was decoupled from leaf phosphorus and potassium concentrations, leaf vein density, and stem vessel traits across all lianas investigated. For four evergreen lianas, there were positive associations of the relative growth rate with the leaf thickness and diameter of the largest vessels. This study is the first to illustrate the relationships of liana growth with leaf and stem traits in the high-elevation subtropical cloud forest. More studies from diverse forest ecosystems are needed to comprehensively understand the mechanism underlying liana growth patterns.

Influence of initial pesticide concentrations in water on chlorpyrifos toxicity and removal by Iris pseudacorus

2013 ◽  
Vol 67 (9) ◽  
pp. 1908-1915 ◽  
Author(s):  
Qinghai Wang ◽  
Juan Yang ◽  
Cui Li ◽  
Bo Xiao ◽  
Xiaoe Que
Keyword(s):  
Growth Rate ◽  
Water Body ◽  
Removal Rate ◽  
Negative Relationship ◽  
Relative Growth ◽  
Hydroponic System ◽  
Initial Concentration ◽  
Iris Pseudacorus ◽  
Increased Sensitivity ◽  
Natural Water Body

For understanding the influence of initial concentrations of pesticides in the water body on removal efficiency of the contaminant by aquatic plants, one hydroponics experiment was used to investigate the influence of initial concentration (1–16 mg L−1) on toxicity and chlorpyrifos removal potential of Iris pseudacorus for 20 days under greenhouse conditions. An increased sensitivity to and reduced removal rate for chlorpyrifos were observed with increasing chlorpyrifos concentration. The relative growth rate (RGR) of I. pseudacorus was significantly inhibited in the presence of 4, 8 and 16 mg L−1 chlorpyrifos, and a negative relationship was also found between RGR and initial pesticide concentration. The half-life of chlorpyrifos was shortened in the hydroponic system with plants, indicating that I. pseudacorus accelerated chlorpyrifos removal from water. But the contribution of the plant to chlorpyrifos removal in the hydroponic phytoremediation system decreased with the increase of initial concentration of chlorpyrifos. The results also indicated that I. pseudacorus can efficiently eliminate chlorpyrifos and may ultimately serve as phytoremediation agents in the natural water body.

scholarly journals THE GROWTH AND ABSORPTION OF NUTRIENTS BY FERTILIZED AND UNFERTILIZED WHITE SPRUCE SEEDLINGS

1966 ◽  
Vol 42 (2) ◽  
pp. 127-136 ◽  
Author(s):  
K. A. Armson
Keyword(s):  
Growth Rate ◽  
Growth And Development ◽  
Dry Weight ◽  
Growing Season ◽  
White Spruce ◽  
Height Growth ◽  
Relative Growth ◽  
Uptake Rates ◽  
Abrupt Changes ◽  
Growth Development

A study was made of the effects of fertilizer additions on the growth and development of white spruce seedlings during their second growing season. In terms of dry weight increment, unfertilized trees grew for only two-thirds of the total growing season available as compared with fertilized trees. The relative growth rate curve for the fertilized trees was smooth with none of the abrupt changes which marked the curve for the unfertilized trees. The pattern of height growth was changed for seedlings which were fertilized. Nutrient uptake rates particularly for phosphorus were different under the two treatments and it is suggested that these differences were related to different patterns of height growth development and root extension.

Competitive ability of cowpea genotypes with different growth habit

Weed Science ◽  
2006 ◽  
Vol 54 (4) ◽  
pp. 775-782 ◽  
Author(s):  
Guangyao Wang ◽  
Milton E. McGiffen ◽  
Jeff D. Ehlers ◽  
Edilene C. S. Marchi
Keyword(s):  
Growth Rate ◽  
Competitive Ability ◽  
Growth Habit ◽  
Biomass Accumulation ◽  
Growing Season ◽  
Similar Reduction ◽  
Relative Growth ◽  
Use Efficiency ◽  
Common Purslane ◽  
Prostrate Growth

Growth habit is an important determinant of competitive ability in legume crops. Erect ‘Iron-Clay’ (IC), semi-erect ‘IT89KD-288’ (288), and prostrate ‘UCR 779’ (779) cowpea genotypes were planted with four densities of common sunflower or common purslane to determine which cowpea growth habit is more competitive to these weeds having markedly different statures. Both sunflower and purslane reduced cowpea relative growth rate (RGR) but at different phases of the growing season. Low-growing purslane had an effect in the earlier part of the season, and sunflower decreased cowpea RGR in the middle of growing season. RGR of genotype IC was the least affected and genotype 779 the most reduced by sunflower. Cowpea apparently compensated for early season purslane competition by increasing RGR after purslane flowering, with RGR for the IC genotype increasing the most and 779 increasing the least. All cowpea genotypes caused a similar reduction in sunflower biomass accumulation; but purslane biomass was most reduced by genotype IC and least affected by genotype 288. Erect genotype IC is more competitive due to its taller stature, greater height growth rate, and higher position of maximal leaf area density, despite a lower photosynthetic rate and light use efficiency than the other cowpea genotypes. Our results suggest that erect cowpea growth habit may be generally more competitive with weeds compared to semi-erect or prostrate growth habit.

Physiological indicators of nitrogen response in a short rotation sycamore plantation. II. Nitrogen metabolism

1993 ◽  
Vol 71 (6) ◽  
pp. 841-847 ◽  
Author(s):  
Timothy J. Tschaplinski ◽  
Richard J. Norby
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Nitrate Reductase ◽  
Nitrogen Fertilization ◽  
Free Amino ◽  
Nitrate Reductase Activity ◽  
Growth Response ◽  
Reductase Activity ◽  
Growing Season ◽  
Relative Growth

American sycamore (Platanus occidentalis L.) seedlings were grown in the field under different urea–nitrogen fertilization regimes to identify nitrogen variables that characterize the growth response. Treatments included fertilization with 50, 150, and 450 kg N/ha, periodic fertilization (three times during the growing season) at 37.5 kg N/ha, and an unfertilized control. Leaf total nitrogen concentration was a poor indicator of plant growth response to nitrogen fertilization. Salt-extractable protein, nitrate, and free amino acid concentrations all trended upward by the end of the growing season as relative growth rate declined, but treatment differences were minimal. Leaf nitrate reductase activity was consistently higher in fertilized trees before substantial leaf senescence had occurred. When leaf loss was evident, all treatments had high levels of nitrate reductase activity. Aspartic acid and glutamic acid were the most prevalent free amino acids in leaves, whereas concentrations of amine-rich amino acids were low. Although several nitrogen variables, including foliar asparagine and glycine concentrations, were positively correlated with relative growth rate (r ≥ 0.7), no single variable closely reflected treatment differences in growth response. Key words: amino acids, nitrogen, nitrate reductase, sycamore.

scholarly journals A comparative study of resource allocation in Pteridium in different Brazilian ecosystems and its relationship with European studies

2014 ◽  
Vol 74 (1) ◽  
pp. 156-165 ◽  
Author(s):  
DM Silva Matos ◽  
RO Xavier ◽  
FCS Tiberio ◽  
RH Marrs
Keyword(s):  
Invasive Species ◽  
Resource Allocation ◽  
South America ◽  
Positive Relationship ◽  
Negative Relationship ◽  
Growing Season ◽  
Similar Data ◽  
Response Range ◽  
The World ◽  
Rhizome Biomass

Pteridium is a cosmopolitan genus that acts as an invasive species in many parts of the world. Most research on this genus has occurred in Europe, and there is a lack of data on it from South America, in spite of causing considerable conservation problems. We compared the biomass allocation of P. esculentum subsp. arachnoideum in two ecosystems in Brazil - Atlantic forest and Brazilian savanna. We measured the biomass of fronds, rhizomes and above-ground litter. We also compared the density, length and biomass of fronds from this Brazilian study with similar data of P. esculentumsubsp. arachnoideum derived from Venezuela and P. aquilinum from Europe. P. esculentum subsp. arachnoideum showed a wide response range. We found a negative relationship between frond and necromass, indicating a negative feedback effect, while a positive relationship was observed between frond and rhizome biomass. The continental comparison of relationships showed that Pteridium responds in a different way in both Brazil and Europe, and that in Brazil fronds tend to be longer and heavier, presumably as a result of the continuous growing season in South America while is shortened in Europe by frost. The paper shows the ability of Pteridium to adapt to different ecosystems.

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