Biological invasion by Myrica faya in Hawaii: Plant demography, nitrogen fixation, ecosystem effects

Journal Article · Fri Sep 01 00:00:00 EDT 1989 · Ecological Monographs; (USA)

DOI:https://doi.org/10.2307/1942601· OSTI ID:7197513

Vitousek, P M; Walker, L R ^[1]

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1. Stanford Univ., California (USA)

Myrica faya, an introduced actinorhizal nitrogen fixer, in invading young volcanic sites in Hawaii Volcanoes National Park. We examined the population biology of the invader and ecosystem-level consequences of its invasion in open-canopied forests resulting from volcanic cinder-fall. Although Myrica faya is nominally dioecious, both males and females produce large amounts of fruit that are utilized by a number of exotic and native birds, particularly the exotic Zosterops japonica. In areas of active colonization, Myrica seed rain under perch trees of the dominant native Metrosideros polymorpha ranged from 6 to 60 seeds m{sup {minus}2} yr{sup {minus}1}; no seeds were captured in the open. Planted seeds of Myrica also germinated an established better under isolated individuals of Metrosideros than in the open. Diameter growth of Myrica is > 15-fold greater than that of Metrosideros, and the Myrica population is increasing rapidly. Rates of nitrogen fixation were measured using the acetylene reduction assay calibrated with {sup 15}N. Myrica nodules reduced acetylene at between 5 and 20 {mu}mol g{sup {minus}1} h{sup {minus}1}, a rate that extrapolated to nitrogen fixation of 18 kg ha{sup {minus}1} in a densely colonized site. By comparison, all native sources of nitrogen fixation summed to 0.2 kg ha{sup {minus}1} yr{sup {minus}1}, and precipitation added < 4 kg ha{sup {minus}1} yr{sup {minus}1}. Measurements of litter decomposition and nitrogen release, soil nitrogen mineralization, and plant growth in bioassays all demonstrated that nitrogen fixed by Myrica becomes available to other organisms as well. We conclude that biological invasion by Myrica faya alters ecosystem-level properties in this young volcanic area; at least in this case, the demography and physiology of one species controls characteristics of a whole ecosystem.

• OSTI ID: 7197513
• Journal Information: Ecological Monographs; (USA), Vol. 59:3; ISSN 0012-9615
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
HAWAII
ECOLOGY
RHIZOBIUM
PLANT GROWTH
NITROGEN 15
NITROGEN FIXATION
POPULATIONS
PUBLIC LANDS
TRACER TECHNIQUES
VOLCANOES
BACTERIA
FEDERAL REGION IX
GROWTH
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
NITROGEN ISOTOPES
NORTH AMERICA
NUCLEI
ODD-EVEN NUCLEI
STABLE ISOTOPES
USA
540211* - Environment
Terrestrial- Basic Studies- Radiometric Techniques- (1990-)