Does Germination Success Differ with Respect to Seed Mass and Germination Season? Experimental Testing of Plant Functional Trait Responses to Grassland Management

AbstractSeed mass is an important plant functional trait linked to germination. For instance, higher-mass seeds often display greater germination compared to lower-mass seeds when exposed to non-stressful conditions. Yet, knowledge pertaining to germination dynamics for different mass-based seed fractions following exposure to abiotic stress is lacking. Here, we assess the germination response of relatively fresh, mass-separated Rudbeckia mollis (Asteraceae) seeds to various simulated seasonal temperatures, supra-optimal temperatures and increasing ageing stress duration. Air density separation yielded three mass-based classes, called light (393 ± 35 μg), intermediate (423 ± 29 μg) and heavy (474 ± 38 μg). Water uptake kinetics indicated that imbibition (0–6 h) and germination lag (6–24 h) were independent of seed mass. Similarly, germination and viability loss of fresh seeds following exposure to seasonal and supra-optimal constant temperatures were independent of mass. However, seed mass influenced germination following increasing ageing stress, with light seeds germinating to a significantly greater extent than intermediate or heavy seeds. For example, final germination per cent in light-class seeds was about 1.7 times greater than intermediate or heavy seeds after 20 d of saturated salt accelerated ageing (SSAA). Seeds stored for 1 year in the laboratory displayed mass-dependent germination patterns similar to seeds following SSAA. Mass-independent germination responses may be a strategy to maintain an annual life history in otherwise difficult environments when R. mollis seeds are relatively fresh. However, differences in germination response between aged and unaged seeds suggest that mass-dependent viability loss may occur in R. mollis.

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Effects of grassland management on plant functional trait composition

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2008.05.016 ◽

2008 ◽

Vol 128 (3) ◽

pp. 137-145 ◽

Cited By ~ 65

Author(s):

S KAHMEN ◽

P POSCHLOD

Keyword(s):

Grassland Management ◽

Functional Trait ◽

Plant Functional Trait

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Faculty Opinions recommendation of Plant functional trait change across a warming tundra biome.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734077082.793556989 ◽

2019 ◽

Author(s):

Benjamin Poulter

Keyword(s):

Functional Trait ◽

Plant Functional Trait

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Leaf Traits of Trees in Tropical Dry Evergreen Forests of Peninsular India

Ecologies ◽

10.3390/ecologies2030015 ◽

2021 ◽

Vol 2 (3) ◽

pp. 268-284

Author(s):

Muthulingam Udayakumar ◽

Thangavel Sekar

Keyword(s):

Negative Relationship ◽

Leaf Traits ◽

Functional Trait ◽

Matter Content ◽

Evergreen Forest ◽

Leaf Life Span ◽

Dry Matter Content ◽

Evergreen Species ◽

Peninsular India ◽

Plant Functional Trait

A plant functional trait study was conducted to know the existing relationship between important leaf traits namely, specific leaf area (SLA), leaf dry matter content (LDMC), and leaf life span (LL) in tropical dry evergreen forest (TDEFs) of Peninsular India. Widely accepted methodologies were employed to record functional traits. The relationships between SLA and LDMC, LDMC and LL, and SLA and LL were measured. Pearson’s coefficient of correlation showed a significant negative relationship between SLA and LDMC, and SLA and LL, whereas a significant positive relationship was prevailed between LDMC and LL. The mean trait values (SLA, LDMC, and LL) of evergreens varied significantly from deciduous species. SLA had a closer relationship with LDMC than LL. Similarly, LL had a closer relationship with SLA than LDMC. Species with evergreen leaf habits dominated forest sites under study. Evergreen species dominate the study area with a high evergreen-deciduous ratio of 5.34:1. The S strategy score of trees indicated a relatively higher biomass allocation to persistent tissues. TDEFs occur in low elevation, semiarid environment, but with the combination of oligotrophic habitat, high temperature and longer dry season these forests were flourishing as a unique evergreen ecosystem in the drier environment. The relationships found between leaf traits were in concurrence with earlier findings. Trees of TDEFs survive on the poor-nutrient habitat with a low SLA, high LDMC, and LL. This study adds baseline data on key leaf traits to plant functional trait database of India.

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