The effect of experimental defoliation on the growth and reproduction of a woodland orchid, Tipularia discolor

1990 ◽  
Vol 68 (8) ◽  
pp. 1812-1816 ◽  
Author(s):  
Dennis F. Whigham
Keyword(s):  
Sexual Reproduction ◽  
Key Words ◽  
Biomass Allocation ◽  
Leaf Biomass ◽  
Woodland Herb ◽  
Defoliation Treatment ◽  
Biomass Component ◽  
Leaf Herbivory ◽  
Growth And Reproduction

Leaves of individuals of Tipularia discolor were subjected to 3 years of manual defoliation to simulate natural patterns of herbivory. Compared with controls, plants that were 100% defoliated did not reproduce sexually after two defoliations, the biomass of new belowground corms decreased significantly in the 1st year and each year thereafter, and leaf biomass declined significantly after three defoliations. Senescence of belowground corms and mortality of entire plants were highest in the 100% defoliation treatment. The responses of plants with 50% defoliation were intermediate. The study demonstrates that belowground corms are the first biomass component to be negatively impacted by complete and partial defoliation. Reductions in corm biomass resulting from leaf herbivory would eventually reduce leaf biomass and sexual reproduction. Key words: woodland herb, herbivory, biomass allocation, reproduction, Tipularia discolor, Orchidaceae, defoliation.

scholarly journals Aboveground Biomass Allocation of Boreal Shrubs and Short-Stature Trees in Northwestern Canada

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 234
Author(s):  
Linda Flade ◽  
Christopher Hopkinson ◽  
Laura Chasmer
Keyword(s):  
Short Stature ◽  
Biomass Allocation ◽  
Aboveground Biomass ◽  
Leaf Biomass ◽  
Sectional Area ◽  
Plant Component ◽  
Cross Sectional ◽  
Allometric Models ◽  
Stem Biomass ◽  
Model Fits

In this follow-on study on aboveground biomass of shrubs and short-stature trees, we provide plant component aboveground biomass (herein ‘AGB’) as well as plant component AGB allometric models for five common boreal shrub and four common boreal short-stature tree genera/species. The analyzed plant components consist of stem, branch, and leaf organs. We found similar ratios of component biomass to total AGB for stems, branches, and leaves amongst shrubs and deciduous tree genera/species across the southern Northwest Territories, while the evergreen Picea genus differed in the biomass allocation to aboveground plant organs compared to the deciduous genera/species. Shrub component AGB allometric models were derived using the three-dimensional variable volume as predictor, determined as the sum of line-intercept cover, upper foliage width, and maximum height above ground. Tree component AGB was modeled using the cross-sectional area of the stem diameter as predictor variable, measured at 0.30 m along the stem length. For shrub component AGB, we achieved better model fits for stem biomass (60.33 g ≤ RMSE ≤ 163.59 g; 0.651 ≤ R2 ≤ 0.885) compared to leaf biomass (12.62 g ≤ RMSE ≤ 35.04 g; 0.380 ≤ R2 ≤ 0.735), as has been reported by others. For short-stature trees, leaf biomass predictions resulted in similar model fits (18.21 g ≤ RMSE ≤ 70.0 g; 0.702 ≤ R2 ≤ 0.882) compared to branch biomass (6.88 g ≤ RMSE ≤ 45.08 g; 0.736 ≤ R2 ≤ 0.923) and only slightly better model fits for stem biomass (30.87 g ≤ RMSE ≤ 11.72 g; 0.887 ≤ R2 ≤ 0.960), which suggests that leaf AGB of short-stature trees (<4.5 m) can be more accurately predicted using cross-sectional area as opposed to diameter at breast height for tall-stature trees. Our multi-species shrub and short-stature tree allometric models showed promising results for predicting plant component AGB, which can be utilized for remote sensing applications where plant functional types cannot always be distinguished. This study provides critical information on plant AGB allocation as well as component AGB modeling, required for understanding boreal AGB and aboveground carbon pools within the dynamic and rapidly changing Taiga Plains and Taiga Shield ecozones. In addition, the structural information and component AGB equations are important for integrating shrubs and short-stature tree AGB into carbon accounting strategies in order to improve our understanding of the rapidly changing boreal ecosystem function.

scholarly journals Tolerance of Swallowworts (Vincetoxicum spp.) to Multiple Years of Artificial Defoliation and Clipping

2016 ◽  
Vol 9 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Lindsey R. Milbrath ◽  
Antonio DiTommaso ◽  
Jeromy Biazzo ◽  
Scott H. Morris
Keyword(s):  
North America ◽  
Seed Production ◽  
Aboveground Biomass ◽  
Root Biomass ◽  
Plant Competition ◽  
Common Garden ◽  
Plant Size ◽  
Tissue Loss ◽  
Defoliation Treatment ◽  
Growth And Reproduction

AbstractThe European vines pale swallowwort and black swallowwort are invading various habitats in northeastern North America. It is unclear how these plants might respond to potential biological control agents, as they experience little herbivore damage in North America, or longer durations of mowing given the reported lack of efficacy of mechanical control. We evaluated the effect of six seasons of artificial defoliation (50 or 100% defoliation once or twice per season) and clipping (once, twice, or four times at 8 cm above the soil level) on the survival, growth, and reproduction of mature plants of the two species grown in a common garden field experiment. No plants died from damage after 6 yr. Black swallowwort produced more aboveground biomass, whereas pale swallowwort produced more root biomass and root crown buds, compared with its congener species. For most damage treatments, root biomass and the number of crown buds and stems increased over time, whereas aboveground biomass and viable seeds per plant generally did not change. Substantial overlap in plant size and seed production occurred among damage treatments and species. The most severe defoliation treatment did not substantially limit growth and reproduction compared with undamaged plants. While two clippings per season sometimes prevented seed production, four clippings per season was the only type of damage that consistently prevented plant growth and eliminated seed production. Pale and black swallowwort display a high tolerance to aboveground tissue loss in high-light environments without plant competition. The annual increase in plant size calls into question the potential efficacy of a defoliating insect against field populations of swallowworts, and it seems likely the only benefits of a long-term mowing regime will be to eliminate seed production.

Differences in recovery between a deciduous and an evergreen ericaceous clonal dwarf shrub after simulated aboveground herbivory and belowground damage

1994 ◽  
Vol 72 (6) ◽  
pp. 853-859 ◽  
Author(s):  
Anne Tolvanen
Keyword(s):  
Sexual Reproduction ◽  
Key Words ◽  
Growth Form ◽  
Clonal Integration ◽  
Simulated Herbivory ◽  
Aboveground Herbivory ◽  
Dry Biomass ◽  
Microtine Rodent ◽  
Vaccinium Myrtillus L ◽  
Rhizome Severing

Insect and microtine rodent herbivory (defoliation and branch clipping, respectively) were simulated in stands of the deciduous Vaccinium myrtillus L. and evergreen V. vitis-idaea L. Rhizome connections around the treated plots were either left intact or severed. Recovery in the plots was monitored for two growth seasons, from 1991 to 1992. It was hypothesized that the evergreen V. vitis-idaea would suffer more from the simulated herbivory treatment than V. myrtillus, but that severing the rhizome connections would decrease recovery of both species, because clonal integration is disrupted and wounding may have a harmful influence on growth. After two growth seasons, recovery was complete from simulated herbivory in V. myrtillus, whereas the new dry biomass was reduced slightly (22 – 37%) or significantly (49%) compared with that of the control in V. vitis-idaea. Rhizome severing reduced the growth of the branches and ramets and the aboveground dry biomass by 34% compared with that of the unsevered control in V. myrtillus. In the evergreen V. vitis-idaea, severing slightly reduced growth, the effect being significant only in the clipped treatment. The results suggest that the deciduous V. myrtillus recovers more rapidly from simulated herbivory than the evergreen V. vitis-idaea. Rhizome severing is more detrimental to the growth of V. myrtillus, but less detrimental to recovery from simulated herbivory. Sexual reproduction decreases more in V. vitis-idaea than in V. myrtillus after damage. Key words: compensation, growth form, herbivory, rhizome severing, Vaccinium

scholarly journals INFLUENCE OF DIETARY CALCIUM-PHOSPHORUS LEVELS ON APPARENT ABSORPTION OF MINERALS AND NITROGEN DURING GROWTH AND REPRODUCTION IN GILTS

1984 ◽  
Vol 64 (2) ◽  
pp. 491-494
Author(s):  
R. R. GRANDHI
Keyword(s):  
Key Words ◽  
Dietary Calcium ◽  
Nutrient Absorption ◽  
Nitrogen Absorption ◽  
Apparent Absorption ◽  
Key Words Calcium ◽  
Calcium Phosphorus ◽  
Phosphorus Levels ◽  
Growth And Reproduction

A higher Ca-P intake during finishing, gestation and lactation periods increased (P < 0.05) the apparent absorption (g/day) of Ca and P during all three periods. Nutrient absorption appeared to differ for Lacombe and Yorkshire gilts. Key words: Calcium, phosphorus, nitrogen, absorption, gilts

Percid Habitat: The River Analogy

1977 ◽  
Vol 34 (10) ◽  
pp. 1936-1940 ◽  
Author(s):  
James F. Kitchell ◽  
Murray G. Johnson ◽  
C. Kenneth Minns ◽  
Kenneth H. Loftus ◽  
Lorne Greig ◽  
...  
Keyword(s):  
Key Words ◽  
Environmental Conditions ◽  
Current Velocity ◽  
Perca Flavescens ◽  
Light Penetration ◽  
Habitat Conditions ◽  
Reproductive Patterns ◽  
Evolutionary Origins ◽  
Reduced Light ◽  
Growth And Reproduction

We propose that the optimum habitat of the percid fishes Perca flavescens, P. fluviatilis, Stizostedton vitreum vitreum, and S. lucioperca in lakes may be defined by the littoral and sublittoral environmental conditions equivalent to those in large, temperate rivers. Analogous habitat conditions include sand or gravel substrate, low current velocity, reduced light penetration (Stizostedion spp. only), temperatures optimal for growth and reproduction, and well-oxygenated spawning substrates. The species' evolutionary origins and reproductive patterns also reflect their riverine ancestral habitat. Evidence in support of the hypothesis is derived from the diversity of papers contributed to the PERCIS Symposium. Key words: Percidae, habitat, theory, Perca, Stizostedion

scholarly journals Variability of quackgrass (Agripyron repens) biotypes in Québec

2005 ◽  
Vol 72 (3) ◽  
pp. 115-121 ◽  
Author(s):  
F.J. Tardif ◽  
G.D. Leroux
Keyword(s):  
Sexual Reproduction ◽  
Biomass Allocation ◽  
Field Experiments ◽  
Dry Weight ◽  
Total Biomass ◽  
Growth Variability ◽  
Rhizome Buds ◽  
Agropyron Repens

Field experiments were conducted in 1985 and 1986 at Sainte-Foy, Quebec, Canada, to characterize the growth variability of 10 quackgrass (Agropyron repens) biotypes collected in Quebec. The growth variables and the pattern of biomass allocation differed significantly among biotypes. Three-fold difference existed among biotypes for the number of tillers and spikes. The number of daughter-shoots varied from 6 to 51. More than 1900 rhizome buds were formed by the most productive biotypes and fewer than 500 by the least productive ones. Biomass varied from 73 to 241 g dry weight between the least and the most productive biotype. The percentage of total biomass allocated to the mother-shoot and the daughter-shoots varied more between years and among biotypes than the percentage allocated to the rhizomes. Reproduction in quackgrass is predominantly vegetative and sexual reproduction is more variable among biotypes and years.

Competition between native and immigrant Polygonum congeners

1993 ◽  
Vol 71 (7) ◽  
pp. 939-945 ◽  
Author(s):  
B. Collins ◽  
G.R. Wein
Keyword(s):  
Key Words ◽  
Plant Height ◽  
Biomass Allocation ◽  
Seed Set ◽  
Niche Differentiation ◽  
Greenhouse Experiment ◽  
Competitive Interactions ◽  
Mature Plant ◽  
Shared Resources ◽  
Density Dependent

Coexistence of annual herbs Polygonum punctatum, a native, and Polygonum caespitosum, an immigrant, may result from (i) niche differentiation that reduces or avoids competition, (ii) competitive equivalence for shared resources, or (iii) interaction between a strong competitor and a species that tolerates competition. We investigated competitive interactions between the Polygonum congeners in a greenhouse experiment using plants grown from seed to seed set. Thinning profiles of monocultures were density dependent but did not differ between the species in monocultures. Biomass allocation to root, shoot, and racemes was not influenced by competition from conspecifics or congeners. Mature plant height and raceme production of both species were negatively affected by congener density; however, the species were not competitively equivalent. Polygonum caespitosum was suppressed into the shorter heights in mixture pots but produced more racemes at all but the greatest congener densities. Key words: competition, coexistence, annual herbs, immigrant.

The role of biomass allocation in the growth response of plants to different levels of light, CO2, nutrients and water: a quantitative review

2000 ◽  
Vol 27 (6) ◽  
pp. 595 ◽  
Author(s):  
Hendrik Poorter ◽  
Oscar Nagel
Keyword(s):  
Leaf Area ◽  
Biomass Allocation ◽  
Mass Fraction ◽  
Plant Biomass ◽  
Growth Parameters ◽  
Meta Analysis ◽  
Carbon Gain ◽  
Leaf Biomass ◽  
Functional Equilibrium ◽  
Leaf Mass

The allocation of biomass to different plant organs depends on species, ontogeny and on the environment experienced by the plant. In this paper we first discuss some methodological tools to describe and analyse the allocation of biomass. Rather than the use of shoot:root ratios, we plead strongly for a subdivision of biomass into at least three compartments: leaves, stems and roots. Attention is drawn to some of the disadvantages of allometry as a tool to correct for size differences between plants. Second, we tested the extent to which biomass allocation of plants follows the model of a ‘functional equilibrium’. According to this model, plants respond to a decrease in above-ground resources with increased allocation to shoots (leaves), whereas they respond to a decrease in below-ground resources with increased allocation to roots. We carried out a meta-analysis of the literature, analysing the effect of various environmental variables on the fraction of total plant biomass allocated to leaves (leaf mass fraction), stem (stem mass fraction) and roots (root mass fraction). The responses to light, nutrients and water agreed with the (qualitative) prediction of the ‘functional equilibrium’ theory. The notable exception was atmospheric CO2, which did not affect allocation when the concentration was doubled. Third, we analysed the quantitative importance of the changes in allocation compared to changes in other growth parameters, such as unit leaf rate (the net difference between carbon gain and carbon losses per unit time and leaf area), and specific leaf area (leaf area: leaf biomass). The effects of light, CO2 and water on leaf mass fractions were small compared to their effects on relative growth rate. The effects of nutrients, however, were large, suggesting that only in the case of nutrients, biomass allocation is a major factor in the response of plants to limiting resource supply.

Shifts of Sexual Reproductive and Vegetative Growth Allocation in Stipa grandis along a Climate Gradient in Inner Mongolia Steppe

2013 ◽  
Vol 726-731 ◽  
pp. 4431-4435 ◽  
Author(s):  
Hui Gao ◽  
Yu Bao Gao ◽  
An Zhi Ren ◽  
Wei Bin Ruan
Keyword(s):  
Resource Allocation ◽  
Sexual Reproduction ◽  
Biomass Allocation ◽  
Vegetative Growth ◽  
Environmental Variability ◽  
Adaptive Strategy ◽  
Percentage Increase ◽  
Growth Allocation ◽  
Allocation Patterns ◽  
The Relationship

Trade-off between vegetative growth and reproduction is an important plant adaptive strategy to environmental variability. The study investigated the Stipa grandis resource allocation and the relationship between its sexual reproduction and climate factors among three sites located along a typical environmental gradient in the Inner Mongolian Plateau. The results show that different climatic characteristics among three habitats cause the growth differentiation of S. grandis. S. grandis exhibits a prominent change on the resource allocation patterns. The number of reproductive tillers and panicles biomass allocation are significantly increased along the gradient of water availability and temperature whereas the number of vegetative tillers and root biomass allocation are reduced. The rate of the percentage increase is prominently reduced although the foliage allocation increased. It suggests that under the environments with drought and high temperature, S. grandis allocates more resources to sexual reproduction but reduces the investment in vegetative growth and asexual reproduction. Moreover, the amount of precipitation in April and May are significantly correlated with the sexual reproductive allocation of S. grandis.

scholarly journals Plasticity of Leaf Traits of Juglans regia L. f. luodianense Liu et Xu Seedlings Under Different Light Conditions in Karst Habitats

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 81
Author(s):  
Deng Wang ◽  
XiaoLong Huang ◽  
JingZhong Chen ◽  
LiXia Li ◽  
Jing Cheng ◽  
...  
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Biomass Allocation ◽  
Specific Leaf Area ◽  
Juglans Regia ◽  
Morphological Characteristics ◽  
Cell Membrane Permeability ◽  
Karst Area ◽  
Leaf Biomass ◽  
Phenotypic Traits

This study examined the effects of light intensity on the plasticity of the leaves of Juglans regia f. luodianense seedlings in karst habitat and how they respond to changes in light intensity. The light intensity of 1-year-old seedlings of J. regia f. luodianense in different niches in a karst area was set as 100% (bare land), 75% (forest margin), 50% (forest gap), and 25% (under forest) of natural light. The material harvested after four months was compared to analyze the differences in various morphological characteristics, biomass allocation, and physiological characteristics of the leaves of seedlings of J. regia f. luodianense, and a comprehensive evaluation of the plasticity indexes was conducted. The results showed that under moderate (50%) full light intensity, the leaf area, specific leaf area, leaf biomass, and chlorophyll content increased, and improved photosynthesis and promoted the accumulation of free proline content and peroxidase (POD) activity. The accumulation of malondialdehyde was also the lowest in this treatment, indicating that the plants had the strongest adaptability under this light intensity. Moreover, under high (75%) full light intensity, the above functional characteristics of plants showed good performance. Under low (25%) full light intensity, plants also had higher specific leaf area, leaf biomass, and photosynthetic parameters. However, under full light, the cell membrane permeability decreased, the chlorophyll accumulation was the lowest, and the photosynthetic index was seriously inhibited. Our results showed that the plasticity of morphological characters was greater than that of biomass allocation and physiological characters; POD activity and stomatal conductance were the highest, followed by leaf area and chlorophyll b, whereas the plasticity of palisade tissue/sponge tissue thickness and lower-epidermis thickness were the lowest. In summary, there are evident differences in the sensitivity and regulation mechanisms of morphological characteristics, biomass allocation, and physiological indices of the seedling leaves of J. regia f. luodianense in response to light intensity. During the stage of seedling establishment, only the plants in the bare ground under full light can be induced to show obvious inhibition of phenotypic traits. In contrast, the plants in the forest margins and gaps and under the forest habitats under light intensity can regulate their own characteristics to maintain their growth and development. The wide light range and strong plasticity of the species might be two of the important reasons for its existence in a highly heterogeneous karst habitat.

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