Litterfall of three subtropical mangrove species in the family Rhizophoraceae

• Published in: Journal of oceanography Vol. 68; no. 6; pp. 841 - 850
• Main Authors: Kamruzzaman, Md, Sharma, Sahadev, Rafiqul Hoque, A. T. M., Hagihara, Akio
• Format: Journal Article
• Language: English
• Published: Japan Springer Japan 01-12-2012; Springer Nature B.V
• Subjects: Biomass; Bruguiera gymnorrhiza; Earth and Environmental Science; Earth Sciences; Ecosystems; Flowers; Forests; Freshwater & Marine Ecology; Fruits; Kandelia; Leaves; Marine; Oceanography; Rhizophora stylosa; Rhizophoraceae; Special Section: Original Article; Summer; Wetlands; ISEW, Japan, Nansei-Shoto, Okinawa Prefect., Okinawa I; Vegetative organs; Reproductive organs; Conversion rate; Wetland; Production load
• ISSN: 0916-8370; 1573-868X
• DOI: 10.1007/s10872-012-0134-8

This study was conducted to evaluate and compare the litterfall dynamics of three mangrove species in the family Rhizophoraceae:
Rhizophora stylosa
,
Kandelia obovata
, and
Bruguiera gymnorrhiza,
in Manko Wetland, Okinawa Island, Japan. Over 3 years, these species showed highest litterfall of leaves and stipules in summer and the lowest litterfall in winter. Litterfall of flowers and fruits peaked in July for
R. stylosa
, and in August and again in October–November for
K. obovata.
Litterfall of flower buds, flowers, and propagules occurred throughout the year for
B. gymnorrhiza
, but was highest in summer. Litterfall of propagules was highest in September and May for
R. stylosa
and
K. obovata
, respectively. Kendall’s coefficient of concordance revealed that the monthly changes for leaf, stipule, flower, and fruit litterfalls of all the species were strongly and significantly concordant among the years. The conversion rate of flowers to propagules was 2.3 % in
R. stylosa
, 5.9 % in
K. obovata
, and 10.3 % in
B. gymnorrhiza
. Total annual litterfall in
R. stylosa
was significantly different from
K. obovata
and
B. gymnorrhiza
; however, the latter two species showed no significant differences. Leaves contributed the most to the total litterfall of all three species, and represented 58.4, 54.0, and 50.4 % of the total litterfall for
R. stylosa
,
K. obovata
, and
B. gymnorrhiza
, respectively. Except for branches and flower bud primordia, all other components of litterfall had clear annual cycles for all three species.
Rhizophora stylosa
and
K. obovata
showed a negative correlation between leaf production and reproductive organ production, but
B. gymnorrhiza
tended to increase leaf production with increasing reproductive organ production.