scholarly journals Effects of increased N and P availability on biomass allocation and root carbohydrate reserves differ between N‐fixing and non‐N‐fixing savanna tree seedlings

2018 ◽  
Vol 8 (16) ◽  
pp. 8467-8476 ◽  
Author(s):  
Varun Varma ◽  
Arockia M. Catherin ◽  
Mahesh Sankaran
Keyword(s):  
Biomass Allocation ◽  
Tree Seedlings ◽  
P Availability ◽  
Carbohydrate Reserves

scholarly journals Effects of increased N and P availability on biomass allocation and root carbohydrate reserves differ between N-fixing and non-N-fixing savanna tree seedlings

2017 ◽  
Author(s):  
Varan Varma ◽  
Arockia M Catherin ◽  
Mahesh Sankaran
Keyword(s):  
Functional Groups ◽  
Biomass Allocation ◽  
Nutrient Availability ◽  
Belowground Biomass ◽  
Dry Forest ◽  
Plant Functional Groups ◽  
Tree Seedlings ◽  
P Availability ◽  
Nutrient Deposition ◽  
Allocation Patterns

AbstractIn mixed tree-grass ecosystems, tree recruitment is limited by demographic bottlenecks to seedling establishment arising from inter- and intra-life form competition, and disturbances such as fire. Enhanced nutrient availability resulting from anthropogenic nitrogen (N) and phosphorus (P) deposition can alter the nature of these bottlenecks by changing seedling growth and biomass allocation patterns, and lead to longer-term shifts in tree community composition if different plant functional groups respond differently to increased nutrient availability. However, the extent to which tree functional types characteristic of savannas differ in their responses to increased N and P availability remains unclear. We quantified differences in above- and belowground biomass, and root carbohydrate contents – parameters known to influence the ability of plants to compete, as well as survive and recover from fires – in seedlings of multiple N-fixing and non-N-fixing tree species characteristic of Indian savanna and dry-forest ecosystems to experimental N and P additions. N-fixers in our study were co-limited by N and P availability, while non-N-fixers were N limited. Although both functional groups increased biomass production following fertilisation, non-N-fixers were more responsive and showed greater relative increases in biomass with fertilisation than N-fixers. N-fixers had greater baseline investment in belowground resources and root carbohydrate stocks, and while fertilisation reduced root:shoot ratios in both functional groups, root carbohydrate content only reduced with fertilisation in non-N-fixers. Our results indicate that, even within a given system, plants belonging to different functional groups can be limited by, and respond differentially to, different nutrients, suggesting that long-term consequences of nutrient deposition are likely to vary across savannas contingent on the relative amounts of N and P being deposited in sites.

scholarly journals Red hot maples: Acer rubrum first-year phenology and growth responses to soil warming

2017 ◽  
Vol 47 (2) ◽  
pp. 159-165 ◽  
Author(s):  
J.A. Wheeler ◽  
N.M. Gonzalez ◽  
K.A. Stinson
Keyword(s):  
Biomass Allocation ◽  
Environmental Conditions ◽  
Acer Rubrum ◽  
Growing Season ◽  
Tree Seedlings ◽  
Red Maple ◽  
Growth Responses ◽  
Soil Warming ◽  
Leaf Production ◽  
Trade Offs

Microhabitat environmental conditions are an important filter for seedling establishment, controlling the availability of optimal recruitment sites. Understanding how tree seedlings respond to warming soil temperature is critical for predicting population recruitment in the future hardwood forests of northeastern North America, particularly as environmental conditions and thus optimal microhabitat availabilities change. We examined the effect of soil warming of 5 °C during the first growing season on germination, survival, phenology, growth, and stem and root biomass allocation in Acer rubrum L. (red maple) seedlings. While there was no effect of soil warming on germination or survival, seedlings growing in warmer soils demonstrated significantly accelerated leaf expansion, delayed autumn leaf senescence, and an extended leaf production period. Further, seedlings growing in warmer soils showed larger leaf area and stem and root structures at the end of the first growing season, with no evidence of biomass allocation trade-offs. Results suggest that A. rubrum seedlings can capitalize on soil warming by adjusting leaf phenology and leaf production, resulting in a longer period of carbon uptake and leading to higher overall biomass. The absence of growth allocation trade-offs suggests that A. rubrum will respond positively to increasing soil temperatures in northeastern forests, at least in the early life stages.

scholarly journals Root responses to neighbouring plants in common bean are mediated by nutrient concentration rather than self/non-self recognition

2011 ◽  
Vol 38 (12) ◽  
pp. 941 ◽  
Author(s):  
Eric A. Nord ◽  
Chaochun Zhang ◽  
Jonathan P. Lynch
Keyword(s):  
Common Bean ◽  
Biomass Allocation ◽  
Root Architecture ◽  
Resource Depletion ◽  
Horizontal Distribution ◽  
Phosphorus Concentration ◽  
P Availability ◽  
Belowground Competition ◽  
Nylon Mesh ◽  
Root Responses

Plants are reported to over-proliferate roots in response to belowground competition, thereby reducing reproductive biomass. This has been cited as an instance of the ‘tragedy of the commons’. Many of the studies that report this response suggest that plants can sense neighbours and discriminate between ‘self’ and ‘non-self’ roots. To test the alternate hypothesis that root responses to a neighbouring plant are mediated by resource depletion, common bean plants were supplied with the same phosphorus (P) fertiliser dose in varying rooting volumes, or with neighbouring plants separated by plastic film, nylon mesh, or no barrier to vary access to a neighbour. Phosphorus concentration, but not the presence of a neighbour or rooting volume, strongly influenced biomass allocation to roots. Root architecture was significantly altered by both neighbours and P availability. When exposed to the roots of a neighbour, plants altered the vertical and horizontal distribution of roots, placing fewer roots in soil domains occupied by roots of a neighbour. These results support the hypothesis that root responses to neighbouring plants are mediated by resource depletion by the neighbour rather than sensing of ‘non-self’ roots and show that the presence of a neighbour may affect root architecture without affecting biomass allocation to roots.

Biomass allocation, regrowth and root carbohydrate reserves of chicory (Cichorium intybus) in response to defoliation in glasshouse conditions

1997 ◽  
Vol 129 (4) ◽  
pp. 447-458 ◽  
Author(s):  
G. D. LI ◽  
P. D. KEMP ◽  
J. HODGSON
Keyword(s):  
Growth Rate ◽  
Biomass Allocation ◽  
Morphological Characteristics ◽  
Cichorium Intybus ◽  
Growth Unit ◽  
Leaf Production ◽  
Carbohydrate Reserves ◽  
Cutting Frequency ◽  
Cutting Height ◽  
Cutting Intensity

Three glasshouse experiments were conducted between 14 September 1993 and 9 January 1996 at the Plant Growth Unit, Massey University, Palmerston North, New Zealand. Experiment 1 studied the effects of cutting height on the regrowth and biomass allocation of chicory (Cichorium intybus L. cv. Grasslands Puna), Expt 2 investigated the biomass allocation and root carbohydrate reserves of three chicory cultivars (Puna, PG90 and Orchies) in response to defoliation, and Expt 3 studied the morphological characteristics and persistence of Puna under extreme defoliation.Cutting height had no significant effect on accumulated secondary leaf and stem masses in Expt 2, but affected secondary leaf mass in Expt 1. However, cutting height significantly reduced root size after two cuttings in both Expts 1 and 2. Three severe cuttings (removing all shoots including visible buds >5 mm on crown) killed 73% of plants, whereas 96% plants survived under lax cutting (100 mm) in Expt 3. Orchies had the highest total reducing sugar concentration in its taproot (56·6%), whereas PG90 had the lowest (32·1%). Therefore, Orchies was the most persistent but had the slowest growth rate, and PG90 the least persistent with the highest growth rate. The performance of Puna was intermediate.It is concluded that the persistence of Puna would be more sensitive to cutting frequency than cutting intensity due to its medium level of root carbohydrate reserves. In contrast, PG90 could be defoliated frequently, but not closely. However, Orchies with its thick taproot was insensitive to cutting intensity and would also be insensitive to cutting frequency due to its larger root carbohydrate reserves. It is suggested that to improve the persistence and enhance the leaf production of Puna by plant breeding the emphasis should be on increasing taproot size without unduly prejudicing herbage production.

Effects of elevated atmospheric carbon dioxide, soil nutrients and water conditions on photosynthetic and growth responses of Alnus hirsuta

2011 ◽  
Vol 38 (9) ◽  
pp. 702 ◽  
Author(s):  
Hiroyuki Tobita ◽  
Akira Uemura ◽  
Mitsutoshi Kitao ◽  
Satoshi Kitaoka ◽  
Yutaka Maruyama ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Biomass Allocation ◽  
Environmental Changes ◽  
Soil Conditions ◽  
Soil Drought ◽  
N Availability ◽  
P Availability ◽  
Growth Responses ◽  
Alnus Hirsuta ◽  
Photosynthetic Properties

The objective of this paper is to clarify the effects of multiple environmental conditions, elevated atmospheric CO2 concentration ([CO2]) and soil conditions on the physiological and morphological properties of Alnus hirsuta Turcz., an N2-fixing species, to predict its responses to environmental changes. We examined the responses of photosynthetic properties, leaf characteristics, biomass and N allocation of A. hirsuta to elevated [CO2], soil N and phosphorus availability, and soil drought by using the results of two experiments. The effects of P availability were more marked than those of N availability and soil drought. The photosynthetic responses of A. hirsuta to elevated [CO2] under high P were considered to be ‘photosynthetic acclimation’, while A. hirsuta presented the obvious ‘photosynthetic downregulation’ to elevated [CO2] under low P. Soil P availability affected the growth responses to elevated [CO2] through effects on these photosynthetic properties and biomass allocation. Though elevated [CO2] caused no marked change in the allometric relationships in biomass, with some exceptions, the responses of N allocation among tissue to elevated [CO2] differed from those of biomass allocation. These results suggest that it is necessary to evaluate N mass allocation as well as biomass when we consider the N2-fixing ability of Alnus under elevated [CO2].

Improved Plant Diversity as a Strategy to Increase Available Soil Phosphorus

2019 ◽  
Vol 103 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Carlos Crusciol ◽  
João Rigon ◽  
Juliano Calonego ◽  
Rogério Soratto
Keyword(s):  
Crop Yields ◽  
Soil Phosphorus ◽  
Cropping System ◽  
P Availability ◽  
P Fractions ◽  
Crop Species ◽  
Soil P ◽  
Residue Decomposition ◽  
Available Soil Phosphorus ◽  
Crop Residue Decomposition

Some crop species could be used inside a cropping system as part of a strategy to increase soil P availability due to their capacity to recycle P and shift the equilibrium between soil P fractions to benefit the main crop. The release of P by crop residue decomposition, and mobilization and uptake of otherwise recalcitrant P are important mechanisms capable of increasing P availability and crop yields.

Development of Efficient Production Systems for Forest Tree Seedlings

2019 ◽  
Vol 73 (2) ◽  
pp. 120-122
Author(s):  
Naoki Negishi ◽  
Katsuhiko Nakahama ◽  
Nobuyuki Urata ◽  
Toshiaki Tanabe
Keyword(s):  
Production Systems ◽  
Forest Tree ◽  
Efficient Production ◽  
Tree Seedlings
Sign in / Sign up

Export Citation Format

Share Document