scholarly journals Root Responses To Neighbors Depend On Neighbor Identity And Resource Distribution

Author(s):  
Tara K. Rajaniemi ◽  
Kelsey Garlick ◽  
Robert E. Drew

Abstract Purpose: In a complex soil environment, competitive and environmental factors will interact with individual traits to influence a plant’s root growth patterns and ability to compete for resources. Here, we examine how root growth of a focal plant, Plantago lanceolata L., responds to resource heterogeneity and to presence of two neighbor species, Centaurea jacea L.and Poa pratensis L. Methods: A full factorial experiment tested the effects of nutrient heterogeneity, neighbors, and their interaction on root responses of Plantago. Roots in shared quadrants of a pot were harvested and quantified by qPCR for plants grown alone or with a neighbor, in patchy or even soil. The effects of experimental treatments on Plantago root mass distribution were tested with two-way ANOVA. Results: When soil resources were evenly distributed, Plantago individuals increased root allocation to soil shared with a Centaurea neighbor but not a Poa neighbor. When soil resources were patchy, Plantago responded more strongly to Poa than to Centuarea, and placed more roots in the high-resource patch. Conclusions: These results demonstrate that plants can respond differently to neighbors depending on species and that integrating multiple cues results in non-additive effects on root behavior.

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 815-818 ◽  
Author(s):  
Thomas E. Marler ◽  
Leah E. Willis

`Mauritius' lychee (Litchi chinensis Sonn.) trees were planted in root observation chambers in July 1990 to determine the pattern of root and stem extension growth during 12 months. Root and stem lengths were measured at intervals ranging from 7 to 18 days from Aug. 1990 until Aug. 1991. During each period of active canopy growth, up to six stem tips were tagged and measured. Root growth was determined by measuring tracings of the extension of each root in a visible plane of the glass wall of the observation chambers. Stem growth was cyclic, with distinct periods of rapid extension followed by periods with no extension. In contrast, root growth was fairly continuous with only three periods of no visible root extension. Mean absolute extension rates were higher for stems than for roots. There were no consistent relationships between the timing of root and stem extension growth.


2010 ◽  
Vol 36 (4) ◽  
pp. 149-159
Author(s):  
Susan Day ◽  
P. Eric Wiseman ◽  
Sarah Dickinson ◽  
J. Roger Harris

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.


1995 ◽  
Vol 120 (2) ◽  
pp. 211-216 ◽  
Author(s):  
J. Roger Harris ◽  
Nina L. Bassuk ◽  
Richard W. Zobel ◽  
Thomas H. Whitlow

The objectives of this study were to determine root and shoot growth periodicity for established Fraxinus pennsylvanica Marsh. (green ash), Quercus coccinea Muenchh. (scarlet oak), Corylus colurna L. (Turkish hazelnut), and Syringa reticulata (Blume) Hara `Ivory Silk' (tree lilac) trees and to evaluate three methods of root growth periodicity measurement. Two methods were evaluated using a rhizotron. One method measured the extension rate (RE) ofindividual roots, and the second method measured change in root length (RL) against an observation grid. A third method, using periodic counts of new roots present on minirhizotrons (MR), was also evaluated. RE showed the least variability among individual trees. Shoot growth began before or simultaneously with the beginning of root growth for all species with all root growth measurement methods. All species had concurrent shoot and root growth, and no distinct alternating growth patterns were evident when root growth was measured by RE. Alternating root and shoot growth was evident, however, when root growth was measured by RL and MR. RE measured extension rate of larger diameter lateral roots, RL measured increase in root length of all diameter lateral roots and MR measured new root count of all sizes of lateral and vertical roots. Root growth periodicity patterns differed with the measurement method and the types of roots measured.


2016 ◽  
Vol 28 (6) ◽  
pp. 621-631 ◽  
Author(s):  
Eric R. Schultz ◽  
Anna-Lisa Paul ◽  
Robert J. Ferl

2020 ◽  
Vol 117 (30) ◽  
pp. 17627-17634
Author(s):  
Avni Malhotra ◽  
Deanne J. Brice ◽  
Joanne Childs ◽  
Jake D. Graham ◽  
Erik A. Hobbie ◽  
...  

Belowground climate change responses remain a key unknown in the Earth system. Plant fine-root response is especially important to understand because fine roots respond quickly to environmental change, are responsible for nutrient and water uptake, and influence carbon cycling. However, fine-root responses to climate change are poorly constrained, especially in northern peatlands, which contain up to two-thirds of the world’s soil carbon. We present fine-root responses to warming between +2 °C and 9 °C above ambient conditions in a whole-ecosystem peatland experiment. Warming strongly increased fine-root growth by over an order of magnitude in the warmest treatment, with stronger responses in shrubs than in trees or graminoids. In the first year of treatment, the control (+0 °C) shrub fine-root growth of 0.9 km m−2y−1increased linearly by 1.2 km m−2y−1(130%) for every degree increase in soil temperature. An extended belowground growing season accounted for 20% of this dramatic increase. In the second growing season of treatment, the shrub warming response rate increased to 2.54 km m−2°C−1. Soil moisture was negatively correlated with fine-root growth, highlighting that drying of these typically water-saturated ecosystems can fuel a surprising burst in shrub belowground productivity, one possible mechanism explaining the “shrubification” of northern peatlands in response to global change. This previously unrecognized mechanism sheds light on how peatland fine-root response to warming and drying could be strong and rapid, with consequences for the belowground growing season duration, microtopography, vegetation composition, and ultimately, carbon function of these globally relevant carbon sinks.


1999 ◽  
Vol 17 (3) ◽  
pp. 141-146
Author(s):  
Jeff L. Sibley ◽  
John M. Ruter ◽  
D. Joseph Eakes

Abstract Growth patterns of seven red maple (Acer rubrum L.) and three Freeman maple (Acer x freemanii E. Murray) cultivars grown in containers in Alabama were evaluated using monthly destructive harvests. The effectiveness of a growth modeling technique not previously described is demonstrated using the data presented for both the Freeman maple (red maple xsilver maple interspecific cross) and red maple categories. Freeman maple cultivars ‘Armstrong’, ‘Celzam’ (Celebration™), and ‘Jeffersred’ (Autumn Blaze™); and red maple cultivars ‘Autumn Flame’, ‘Fairview Flame’, ‘Landsburg’ (Firedance™), ‘Franksred’ (Red Sunset™), ‘Olson’ (Northfire™), ‘Northwood’, and ‘October Glory®’ were studied. Uniform liners of each cultivar were planted in 9.1-liter (#3) containers in March 1996. More than 75% of seasonal height and diameter growth was complete for most cultivars before mid-August, while only 25% of root growth had occurred by the end of August. The remaining 75% of root growth occurred from August through November. The greatest overall growth (based on height, diameter, and root growth increase) was for ‘Autumn Flame’ and ‘October Glory®’, both red maple cultivars; and Freeman maple cultivars ‘Celzam’ and ‘Jeffersred’. The least overall growth (based on height, diameter, and root growth increase), was for red maple cultivars ‘Northwood’ and ‘Landsburg’.


HortScience ◽  
1990 ◽  
Vol 25 (1) ◽  
pp. 84-86 ◽  
Author(s):  
R.J. Cooper ◽  
P.C. Bhowmik ◽  
L.A. Spokas

Field experiments were conducted to determine the response of five widely used Kentucky bluegrass (Poa pratensis L.) cultivars (Adelphi, Baron, Bensun, Merion, and Touchdown) to preemergence applications of the herbicide pendimethalin. Pendimethalin applied during 2 years at 1.7 or 3.4 kg·ha-1 (a.i.) controlled smooth crabgrass [Digitaria ischaemum (Schreb. ex Schweig.) Schreb. ex Muhl.] effectively without injury to turf. Pendimethalin at 3.4 kg·ha-1 resulted in a short-term suppression of root growth immediately following application in the first year of the study. The reduction was transitory and subsequent rooting and rhizome growth were unaffected by pendimethalin. Cultivar × pendimethalin level interactions were not significant during the study. Thus, the herbicide appears to be a safe, effective preemergence material for crabgrass control in Kentucky bluegrass turf. Chemical name used: N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin).


2019 ◽  
Vol 49 (11) ◽  
pp. 1441-1452
Author(s):  
Jouni Kilpeläinen ◽  
Timo Domisch ◽  
Tarja Lehto ◽  
Leena Finér ◽  
Pedro J. Aphalo ◽  
...  

Tree roots comprise a huge carbon pool. Their dynamics are driven by environmental factors and thereby affected by climate change. We studied the effects of soil temperature on root and shoot phenology and their linkages in Norway spruce (Picea abies (L.) Karst.). Saplings were grown in controlled-environment rooms for three simulated growing seasons (GS1, GS2, and GS3). Soil-temperature treatments of 9, 13, 18, and 21 °C were applied during GS2. Root growth was monitored with minirhizotrons and commenced in all treatments simultaneously. Temporal growth patterns of short and long roots were usually bimodal. Root growth was very low during the coldest treatment of GS2 but increased during GS3 as an aftereffect. During GS3, growth of short roots continued later after colder treatments than warmer treatments. Reduced sink strength of roots and increased carbohydrate accumulation into needles at 9 °C during GS2 probably enabled compensatory root growth under restored temperatures during GS3. Soil temperature did not affect shoot phenology, and root and shoot phenology varied between growing seasons; thus, the linkage of root and shoot phenology was inconsistent. In warmer soil, root longevity was shorter and turnover rate was higher than in colder soil. This can further affect soil carbon dynamics and ecosystem carbon cycling in boreal forest ecosystems.


1985 ◽  
Vol 65 (1) ◽  
pp. 137-143
Author(s):  
S. H. NELSON ◽  
G. L. McCLENNAN

The growth and development of Kentucky bluegrass was studied for 3 yr on eight sand blends consisting of variable particle sizes. All were perched over a coarse layer (6–12 mm diam). No differences in germination, establishment, or color over the 3 yr were observed. Without turf the hydraulic conductivity varied greatly in the sand blends. The high conductivity levels were greatly reduced with the developing turf. There was greater downward water movement in those plots with most of the finer particles removed and this greater percolation continued throughout the experiment as the turf developed. In the compacted plots, however, significant differences in percolation rates had disappeared by the third year. When most of the finer particles had been removed, there was a trend toward less total root production with a redistribution of roots to the middle portions of the profiles. This trend was more evident on the compacted plots. The study demonstrated that developing turf has an ameliorating effect on hydraulic conductivity on these vastly different sand blends and suggests that sands, even though not in the recommended range of particle size, can still offer relief to the compaction, drainage, and root growth problems encountered in Kentucky bluegrass playing fields.Key words: Poa pratensis, perched water table, hydraulic conductivity, root growth, compaction


Sign in / Sign up

Export Citation Format

Share Document