Seedling Growth and Biomass Production under Different Light Availability Levels and Competition Types

Light availability is a crucial resource determining seedling survival, establishment, and growth. Competition for light is asymmetric, giving the taller individuals a competitive advantage for obtaining light resources. Species-specific traits, e.g., shade tolerance, rooting depth, and leaf morphology, determine their strategical growth response under limited resource availability and different competitive interactions. We established a controlled pot experiment using European beech, Norway spruce, and Douglas fir seedlings and applying three different light availability levels—10%, 20%, and 50%. The experiment’s main aim was to better understand the effects of light availability and competition type on the growth, growth allocation, and biomass production of recently planted seedlings. We planted four seedlings per pot in either monocultures or mixtures of two species. Relative height and diameter growth and aboveground woody biomass of seedlings increased with increasing light availability. All seedlings allocated more growth to height than diameter with decreasing light availability. Seedlings that reached on average greater height in the previous year allocated less growth to height in the following year. Additionally, there were general differences in growth allocation to the height between gymnosperms and angiosperms, but we did not find an effect of the competitor’s identity. Our mixture effect analysis trends suggested that mixtures of functionally dissimilar species are more likely to produce higher biomass than mixtures of more similar species such as the two studied conifers. This finding points towards increased productivity through complementarity.

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Variation in vegetation cover and seedling performance of tree species in a forest-savanna ecotone

Journal of Tropical Ecology ◽

10.1017/s0266467418000469 ◽

2019 ◽

Vol 35 (2) ◽

pp. 74-82 ◽

Cited By ~ 2

Author(s):

Hamza Issifu ◽

George K. D. Ametsitsi ◽

Lana J. de Vries ◽

Gloria Djaney Djagbletey ◽

Stephen Adu-Bredu ◽

...

Keyword(s):

Vegetation Cover ◽

Seedling Recruitment ◽

Seedling Survival ◽

Tree Cover ◽

First Year ◽

Transplant Experiment ◽

Tree Seedling ◽

Savanna Woodland ◽

Specific Effects ◽

Species Specific

AbstractDifferential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.

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Retention of relict satellite DNA sequences in Anemone (Ranunculaceae)

Acta Botanica Croatica ◽

10.2478/v10184-012-0010-z ◽

2013 ◽

Vol 72 (1) ◽

pp. 1-133 ◽

Cited By ~ 2

Author(s):

Višnja Besendorfer ◽

Jelena Mlinarec

Keyword(s):

Dna Sequences ◽

Southern Hybridization ◽

Repeat Unit ◽

Similar Species ◽

Genomic Component ◽

Library Hypothesis ◽

Species Specific ◽

Eukaryotic Organisms ◽

Fish Signal

Abstract Satellite DNAis a genomic component present in virtually all eukaryotic organisms. The turnover of highly repetitive satellite DNAis an important element in genome organization and evolution in plants. Here we study the presence, physical distribution and abundance of the satellite DNAfamily AhTR1 in Anemone. Twenty-two Anemone accessions were analyzed by PCR to assess the presence of AhTR1, while fluorescence in situ hybridization and Southern hybridization were used to determine the abundance and genomic distribution of AhTR1. The AhTR1 repeat unit was PCR-amplified only in eight phylogenetically related European Anemone taxa of the Anemone section. FISH signal with AhTR1 probe was visible only in A. hortensis and A. pavonina, showing localization of AhTR1 in the regions of interstitial heterochromatin in both species. The absence of a FISH signal in the six other taxa as well as weak signal after Southern hybridization suggest that in these species AhTR1 family appears as relict sequences. Thus, the data presented here support the »library hypothesis« for AhTR1 satellite evolution in Anemone. Similar species-specific satellite DNAprofiles in A. hortensis and A. pavonina support the treatment of A. hortensis and A. pavonina as one species, i.e. A. hortensis s.l.

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Duplex DNA barcoding allows accurate species determination of morphologically similar limpets (Patella spp.) from non-destructive sampling

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315416000813 ◽

2016 ◽

Vol 97 (7) ◽

pp. 1479-1482 ◽

Cited By ~ 1

Author(s):

Thomas J. Ashton ◽

Meriem Kayoueche-Reeve ◽

Andrew J. Blight ◽

Jon Moore ◽

David M. Paterson

Keyword(s):

Dna Barcoding ◽

Species Abundance ◽

Microscopic Analysis ◽

Cost Effective ◽

Field Studies ◽

Similar Species ◽

Species Determination ◽

Destructive Sampling ◽

Species Specific ◽

Non Destructive

Accurate discrimination of two morphologically similar species of Patella limpets has been facilitated by using qPCR amplification of species-specific mitochondrial genomic regions. Cost-effective and non-destructive sampling is achieved using a mucus swab and simple sample lysis and dilution to create a PCR template. Results show 100% concurrence with dissection and microscopic analysis, and the technique has been employed successfully in field studies. The use of highly sensitive DNA barcoding techniques such as this hold great potential for improving previously challenging field assessments of species abundance.

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Competition for Light Affects Alfalfa Biomass Production More Than Its Nutritive Value in an Olive-Based Alley-Cropping System

Forests ◽

10.3390/f12020233 ◽

2021 ◽

Vol 12 (2) ◽

pp. 233

Author(s):

Alberto Mantino ◽

Cristiano Tozzini ◽

Enrico Bonari ◽

Marcello Mele ◽

Giorgio Ragaglini

Keyword(s):

Biomass Production ◽

Nutritive Value ◽

Alley Cropping ◽

Light Availability ◽

Agroforestry Systems ◽

Tree Canopy ◽

Soil Protection ◽

Olive Orchard ◽

Competition For Light ◽

Perennial Legumes

Cropping among trees with perennial legumes is one option for increasing agro-ecosystem services, such as improving the nitrogen supply and increasing soil protection by herbaceous vegetation. Moreover, cropping under the canopy of olive trees should diversify the farm production, compared to the traditional fallow management. Among perennial legumes, alfalfa (Medicago sativa L.) produces abundant biomass under Mediterranean rainfed condition. Based on this, a two-year field experiment was implemented in southern Tuscany in a rainfed olive orchard to test the competition for light effects on alfalfa biomass production and nutritive value. Light availability under the tree canopy was measured by hemispherical photos. In both years, the alfalfa yield of under-canopy varied according to the tree presence. A significant relationship between biomass production and light availability was recorded. The nutritive value of under-canopy alfalfa was similar to that of the open-grown alfalfa. However, same significant differences did however occur, between shaded and sole crop. When differences were found, under-canopy herbage was characterised by a higher content of crude protein and a lower content of fibre with respect to open-grown. In a hilly silvoarable olive orchard, alfalfa biomass accumulation was reduced mainly due to scarce light availability, therefore tree management such as pruning and plantation layout can enhance the herbage productivity. Studying shade tolerant forage legumes in order to enhance the yield and nutritive value of herbage production in rainfed agroforestry systems is essential.

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Time shifts in height and diameter growth allocation in understory European beech (Fagus sylvatica L.) following canopy release

Trees ◽

10.1007/s00468-018-1779-8 ◽

2018 ◽

Vol 33 (2) ◽

pp. 333-344 ◽

Cited By ~ 1

Author(s):

Estelle Noyer ◽

François Ningre ◽

Jana Dlouhá ◽

Mériem Fournier ◽

Catherine Collet

Keyword(s):

Fagus Sylvatica ◽

European Beech ◽

Diameter Growth ◽

Growth Allocation ◽

Fagus Sylvatica L

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Contemporary Concepts of Root System Architecture of Urban Trees

Arboriculture & Urban Forestry ◽

10.48044/jauf.2010.020 ◽

2010 ◽

Vol 36 (4) ◽

pp. 149-159

Author(s):

Susan Day ◽

P. Eric Wiseman ◽

Sarah Dickinson ◽

J. Roger Harris

Keyword(s):

Built Environment ◽

Root Growth ◽

Root System ◽

Root Architecture ◽

Root Systems ◽

Growth Patterns ◽

Urban Trees ◽

Rooting Depth ◽

Similar Species ◽

Urban Settings

Knowledge of the extent and distribution of tree root systems is essential for managing trees in the built environment. Despite recent advances in root detection tools, published research on tree root architecture in urban settings has been limited and only partially synthesized. Root growth patterns of urban trees may differ considerably from similar species in forested or agricultural environments. This paper reviews literature documenting tree root growth in urban settings as well as literature addressing root architecture in nonurban settings that may contribute to present understanding of tree roots in built environments. Although tree species may have the genetic potential for generating deep root systems (>2 m), rooting depth in urban situations is frequently restricted by impenetrable or inhospitable soil layers or by underground infrastructure. Lateral root extent is likewise subject to restriction by dense soils under hardscape or by absence of irrigation in dry areas. By combining results of numerous studies, the authors of this paper estimated the radius of an unrestricted root system initially increases at a rate of approximately 38 to 1, compared to trunk diameter; however, this ratio likely considerably declines as trees mature. Roots are often irregularly distributed around the tree and may be influenced by cardinal direction, terrain, tree lean, or obstacles in the built environment. Buttress roots, tap roots, and other root types are also discussed.

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Initial Survival and Development of Planted European Beech (Fagus sylvatica L.) and Small-Leaved Lime (Tilia cordata Mill.) Seedlings Competing with Black Cherry (Prunus serotina Ehrh.)

Plants ◽

10.3390/plants9060677 ◽

2020 ◽

Vol 9 (6) ◽

pp. 677

Author(s):

Sarah L. Hasstedt ◽

Peter Annighöfer

Keyword(s):

Fagus Sylvatica ◽

Tree Species ◽

Survival Rates ◽

Light Availability ◽

European Beech ◽

Prunus Serotina ◽

Tilia Cordata ◽

Black Cherry ◽

Light Gradient ◽

Fagus Sylvatica L

Black cherry (Prunus serotina Ehrh.) is considered one of the most invasive tree species in central Europe and causes problems for both nature conservation and silviculture. Besides mechanical control treatments, a suggested control method to prevent its ongoing spread is to underplant shade-tolerant native tree species. Therefore, we combined two mechanical treatments, with underplanting of European beech (Fagus sylvatica L.) or small-leaved lime (Tilia cordata Mill.) on fenced and unfenced plots. After the first growing season, survival rates were evaluated, and selected seedlings were destructively harvested to analyze their growth performance and leaf morphology in association with the different light regimes resulting from mechanical treatments Survival rates for both seedlings were very high (>95%). Survival rates were higher on fenced plots than on unfenced plots, most likely as result of browsing. The mortality of F. sylvatica decreased with increasing light availability on fenced plots. The mortality of T. cordata did not change along the light gradient. After one vegetation period no differences with respect to biomass allocation could be detected along the light gradient. However, the specific leaf areas of both species responded similarly, decreasing with increasing light availability. In summary, both species were able to establish and survive in the dense P. serotina understory and might have the potential to outcompete the invasive alien species in the long run.

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Light-dependent seedling survival and growth of four tree species in Costa Rican second-growth rain forests

Journal of Tropical Ecology ◽

10.1017/s026646740500235x ◽

2005 ◽

Vol 21 (4) ◽

pp. 383-395 ◽

Cited By ~ 31

Author(s):

Silvia Iriarte Vivar Balderrama ◽

Robin L. Chazdon

Keyword(s):

Tree Species ◽

Seedling Survival ◽

Light Availability ◽

Light Transmittance ◽

Growth Responses ◽

Low Light ◽

Growth Increments ◽

Light Gradient ◽

Second Growth ◽

Survival And Growth

The dependence of tree seedling survival and growth on light availability was evaluated over 15 mo in three second-growth, wet forest stands (15–18 y old) in north-eastern Costa Rica. Seedlings of four canopy tree species (Dipteryx panamensis, Hyeronima alchorneoides, Virola koschnyi and Vochysia guatemalensis) were planted into four canopy treatments in three replicated stands and in a pasture site, spanning a nearly complete gradient of light availability. Survival and growth of all species increased in response to increasing light availability, but species differed in survival in shaded microsites (6–20% light transmittance) and in growth increments per light increase. Hyeronima showed the highest mortality at low light levels and the highest relative height growth increase per light increase. In contrast, Virola showed high survival at low and moderate light, but showed the lowest leaf area and above-ground biomass per light increase among all species. Dipteryx and Vochysia maintained relatively high rates of survival and growth across the entire light gradient. Hyeronima and Virola showed trade-offs between growth and survival responses to light, unlike Dipteryx and Vochysia. Differences among species in seedling survival at low light may be determined by a variety of physiological and morphological traits that may or may not be mechanistically linked to growth responses.

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Employing plant functional groups to advance seed dispersal ecology and conservation

AoB Plants ◽

10.1093/aobpla/plz006 ◽

2019 ◽

Vol 11 (2) ◽

Cited By ~ 8

Author(s):

Clare Aslan ◽

Noelle G Beckman ◽

Haldre S Rogers ◽

Judie Bronstein ◽

Damaris Zurell ◽

...

Keyword(s):

Seed Dispersal ◽

Functional Groups ◽

Community Dynamics ◽

Single Species ◽

Plant Functional Groups ◽

Similar Species ◽

Seed Dispersal Effectiveness ◽

Data Collection And Analysis ◽

Population And Community Dynamics ◽

Species Specific

Abstract Seed dispersal enables plants to reach hospitable germination sites and escape natural enemies. Understanding when and how much seed dispersal matters to plant fitness is critical for understanding plant population and community dynamics. At the same time, the complexity of factors that determine if a seed will be successfully dispersed and subsequently develop into a reproductive plant is daunting. Quantifying all factors that may influence seed dispersal effectiveness for any potential seed-vector relationship would require an unrealistically large amount of time, materials and financial resources. On the other hand, being able to make dispersal predictions is critical for predicting whether single species and entire ecosystems will be resilient to global change. Building on current frameworks, we here posit that seed dispersal ecology should adopt plant functional groups as analytical units to reduce this complexity to manageable levels. Functional groups can be used to distinguish, for their constituent species, whether it matters (i) if seeds are dispersed, (ii) into what context they are dispersed and (iii) what vectors disperse them. To avoid overgeneralization, we propose that the utility of these functional groups may be assessed by generating predictions based on the groups and then testing those predictions against species-specific data. We suggest that data collection and analysis can then be guided by robust functional group definitions. Generalizing across similar species in this way could help us to better understand the population and community dynamics of plants and tackle the complexity of seed dispersal as well as its disruption.

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Gaps in a gappy forest: plant resources, longleaf pine regeneration, and understory response to tree removal in longleaf pine savannas

Canadian Journal of Forest Research ◽

10.1139/x01-003 ◽

2001 ◽

Vol 31 (5) ◽

pp. 765-778 ◽

Cited By ~ 103

Author(s):

John P McGuire ◽

Robert J Mitchell ◽

E Barry Moser ◽

Stephen D Pecot ◽

Dean H Gjerstad ◽

...

Keyword(s):

Seedling Survival ◽

Longleaf Pine ◽

Light Availability ◽

Pinus Palustris ◽

Understory Vegetation ◽

Net N Mineralization ◽

Plant Resources ◽

Pine Seedlings ◽

Pine Regeneration ◽

Tree Removal

Resource availability and planted longleaf pine (Pinus palustris Mill.) seedling and understory vegetation response within and among three sizes of experimentally created canopy gaps (0.11, 0.41, 1.63 ha) in a mature longleaf pine savanna were investigated for 2 years. Longleaf pine seedlings and understory vegetation showed increased growth in gaps created by tree removal. Longleaf pine seedling growth within gaps was maximized approximately 18 m from the uncut savanna. Increased longleaf pine seedling survival under the uncut savanna canopy observed after the first year suggests that the overstory may facilitate establishment of longleaf pine seedlings rather than reduce survival through competition. Despite the relative openness of the uncut longleaf pine forest, light quantity was increased by tree removal. Light was also the resource most strongly correlated with seedling and understory vegetation growth. Although net N mineralization was correlated to seedling response, the amount of variation explained was low relative to light. Belowground (root) gaps were not strong, in part because of non-pine understory roots increasing in biomass following tree removal. These results suggest that regeneration of longleaf pine may be maximized within gap sizes as small as approximately 0.10 ha, due largely to increases in light availability.

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