Irregular rain cues and the germination and seedling survival of a Panamanian shrub (Hybanthus prunifolius)

Carol K Augspurger

Research output: Contribution to journalArticle

Abstract

Seeds of the Panamanian shrub, Hybanthus prunifolius (Schult.) Schulze (Violaceae) are dispersed at different times in different years ((March to June) and are exposed to the irregular rainfall of the dry season in some years. Fluctuations in soil moisture in the dry season represent suboptimal conditions for germination and seedling survival. There are no mechanisms to prevent germination prior to the arrival of consistent rains in the wet season. Among three natural cohorts of seeds followed in two years, the cohort experiencing the longest time from sowing to consistent rains had the highest germination, but it also had the longest time lag from sowing to, beginning of germination, longest germination period, and lowest survival of seedlings 3 months after sowing. Seeds were also induced experimentally to germinate under 14 different moisture patterns. The patterns encompassed 1) varying lengths of moisture before a dry period, 2) inconsistent moisture, and 3) varying lengths of dryness prior to any moisture. Mortality of seeds by fungal infection occurred if the wet period was delayed. But germination was less affected by fluctuations than was seedling survival. Length of the first wet period and frequency of occurrence of the wet period both affected germination levels. Survival and development of seedlings was influenced by the number of days exposed to dry conditions and by the stage of development at the beginning of the dry period. Young seedlings suffered attrition due to drought stress, and older seedlings died from fungal attack. Results from field and experimental sowing of seeds both indicate that this perennial species has minimal defense against germination when conditions are suboptimal for seedling survival. Undoubtedly there is more recruitment in some years than in others.

Original languageEnglish (US)
Pages (from-to)53-59
Number of pages7
JournalOecologia
Volume44
Issue number1
DOIs
StatePublished - Dec 1 1979

Fingerprint

Hybanthus
germination
shrub
shrubs
seedling
rain
seedlings
sowing
seed
moisture
seeds
dry season
Violaceae
drought stress
wet season
water stress
soil moisture
soil water

ASJC Scopus subject areas

  • Ecology

Cite this

Irregular rain cues and the germination and seedling survival of a Panamanian shrub (Hybanthus prunifolius). / Augspurger, Carol K.

In: Oecologia, Vol. 44, No. 1, 01.12.1979, p. 53-59.

Research output: Contribution to journalArticle

@article{d268405881164d90933fedab7c8c3037,
title = "Irregular rain cues and the germination and seedling survival of a Panamanian shrub (Hybanthus prunifolius)",
abstract = "Seeds of the Panamanian shrub, Hybanthus prunifolius (Schult.) Schulze (Violaceae) are dispersed at different times in different years ((March to June) and are exposed to the irregular rainfall of the dry season in some years. Fluctuations in soil moisture in the dry season represent suboptimal conditions for germination and seedling survival. There are no mechanisms to prevent germination prior to the arrival of consistent rains in the wet season. Among three natural cohorts of seeds followed in two years, the cohort experiencing the longest time from sowing to consistent rains had the highest germination, but it also had the longest time lag from sowing to, beginning of germination, longest germination period, and lowest survival of seedlings 3 months after sowing. Seeds were also induced experimentally to germinate under 14 different moisture patterns. The patterns encompassed 1) varying lengths of moisture before a dry period, 2) inconsistent moisture, and 3) varying lengths of dryness prior to any moisture. Mortality of seeds by fungal infection occurred if the wet period was delayed. But germination was less affected by fluctuations than was seedling survival. Length of the first wet period and frequency of occurrence of the wet period both affected germination levels. Survival and development of seedlings was influenced by the number of days exposed to dry conditions and by the stage of development at the beginning of the dry period. Young seedlings suffered attrition due to drought stress, and older seedlings died from fungal attack. Results from field and experimental sowing of seeds both indicate that this perennial species has minimal defense against germination when conditions are suboptimal for seedling survival. Undoubtedly there is more recruitment in some years than in others.",
author = "Augspurger, {Carol K}",
year = "1979",
month = "12",
day = "1",
doi = "10.1007/BF00346397",
language = "English (US)",
volume = "44",
pages = "53--59",
journal = "Oecologia",
issn = "0029-8519",
publisher = "Springer Verlag",
number = "1",

}

TY - JOUR

T1 - Irregular rain cues and the germination and seedling survival of a Panamanian shrub (Hybanthus prunifolius)

AU - Augspurger, Carol K

PY - 1979/12/1

Y1 - 1979/12/1

N2 - Seeds of the Panamanian shrub, Hybanthus prunifolius (Schult.) Schulze (Violaceae) are dispersed at different times in different years ((March to June) and are exposed to the irregular rainfall of the dry season in some years. Fluctuations in soil moisture in the dry season represent suboptimal conditions for germination and seedling survival. There are no mechanisms to prevent germination prior to the arrival of consistent rains in the wet season. Among three natural cohorts of seeds followed in two years, the cohort experiencing the longest time from sowing to consistent rains had the highest germination, but it also had the longest time lag from sowing to, beginning of germination, longest germination period, and lowest survival of seedlings 3 months after sowing. Seeds were also induced experimentally to germinate under 14 different moisture patterns. The patterns encompassed 1) varying lengths of moisture before a dry period, 2) inconsistent moisture, and 3) varying lengths of dryness prior to any moisture. Mortality of seeds by fungal infection occurred if the wet period was delayed. But germination was less affected by fluctuations than was seedling survival. Length of the first wet period and frequency of occurrence of the wet period both affected germination levels. Survival and development of seedlings was influenced by the number of days exposed to dry conditions and by the stage of development at the beginning of the dry period. Young seedlings suffered attrition due to drought stress, and older seedlings died from fungal attack. Results from field and experimental sowing of seeds both indicate that this perennial species has minimal defense against germination when conditions are suboptimal for seedling survival. Undoubtedly there is more recruitment in some years than in others.

AB - Seeds of the Panamanian shrub, Hybanthus prunifolius (Schult.) Schulze (Violaceae) are dispersed at different times in different years ((March to June) and are exposed to the irregular rainfall of the dry season in some years. Fluctuations in soil moisture in the dry season represent suboptimal conditions for germination and seedling survival. There are no mechanisms to prevent germination prior to the arrival of consistent rains in the wet season. Among three natural cohorts of seeds followed in two years, the cohort experiencing the longest time from sowing to consistent rains had the highest germination, but it also had the longest time lag from sowing to, beginning of germination, longest germination period, and lowest survival of seedlings 3 months after sowing. Seeds were also induced experimentally to germinate under 14 different moisture patterns. The patterns encompassed 1) varying lengths of moisture before a dry period, 2) inconsistent moisture, and 3) varying lengths of dryness prior to any moisture. Mortality of seeds by fungal infection occurred if the wet period was delayed. But germination was less affected by fluctuations than was seedling survival. Length of the first wet period and frequency of occurrence of the wet period both affected germination levels. Survival and development of seedlings was influenced by the number of days exposed to dry conditions and by the stage of development at the beginning of the dry period. Young seedlings suffered attrition due to drought stress, and older seedlings died from fungal attack. Results from field and experimental sowing of seeds both indicate that this perennial species has minimal defense against germination when conditions are suboptimal for seedling survival. Undoubtedly there is more recruitment in some years than in others.

UR - http://www.scopus.com/inward/record.url?scp=0002195628&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0002195628&partnerID=8YFLogxK

U2 - 10.1007/BF00346397

DO - 10.1007/BF00346397

M3 - Article

VL - 44

SP - 53

EP - 59

JO - Oecologia

JF - Oecologia

SN - 0029-8519

IS - 1

ER -