Author
![]() |
Rayamajhi, Min |
![]() |
VAN, T - Retired ARS Employee |
![]() |
Pratt, Paul |
![]() |
Center, Ted |
Submitted to: Wetlands Ecology and Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/29/2005 Publication Date: 8/15/2006 Citation: Rayamajhi, M.B., Van, T.K., Pratt, P.D., Center, T.D. 2006. Temporal and structural effects of stands on litter production in Melaleuca quinquenervia dominated wetlands of South Florida. Wetlands Ecology and Management. 14:303-316. 2006. Interpretive Summary: Melaleuca dominates large areas of the Florida Everglades and has transformed its sedge-dominated marshes into melaleuca forests. Despite its prevalence, very little is known about the litterfall (stem, leaf and bark) productivity of these melaleuca forests in permanently-, seasonally-, and non-flooded (only flooded during storm) habitats. Also, litter production may vary by forest age. Melaleuca wood components and mature seed-capsules comprised the largest and the smallest portions of aboveground biomass, respectively, while leaves, fine stems, mature fruits, bud scales, floral structures, and residues represented decreasingly smaller fractions of the litter during the succeeding year. Dry weight proportion of leaves in litter was greatest (80.9%) in non-flooded and least (69.1%) in permanently flooded habitats. It was also greatest in small (85.6%) and least in large (64.7%) tree stands. Mature-fruit fractions in litter were highest in large-tree stands. Seasonally flooded habitats had the most litterfall, wherein small-, intermediate-, and large-tree stands generated 0.662, 0.882, and 1.128 kg m-2 yr-1, respectively. Dry weight of stems, leaves, bud scales, floral structures, and mature fruit fractions in litter increased as the predominant size of the trees in the stand increased. Total annual litter production was highest during 1999-2000. Leaf fall occurred year-round with maximal amount during April, July, and October. Highest amounts of bud scales and floral structures fell during October-January, which corresponded with flushes of vegetative growth and major flowering events. Overall, melaleuca alone accounted for nearly 99% of the total litterfall dry weight in all habitats and months sampled. The amount of non-melaleuca litter was greater in small-tree stands than in intermediate- or large-tree stands. Litterfall data of this nature will be helpful in detecting changes occurring in melaleuca canopies in response to biological control impact and in prescribing site-specific management strategies. Technical Abstract: Melaleuca quinquenervia (melaleuca) dominates large areas of the Florida Everglades in the southeastern USA where it has transformed sedge-dominated marshes into melaleuca forests. Despite its prevalence, very little is known about the ecology and stand dynamics of this invasive tree. We delineated large-, intermediate-, and small-tree stands in non-flooded, seasonally flooded and permanently flooded areas of Florida in 1997, measured their biological attributes, and then quantified litterfall components for 3-4 year periods. Melaleuca wood components and mature seed-capsules comprised the largest and the smallest portions of aboveground biomass, respectively, while leaves, fine stems, mature fruits, bud scales, floral structures, and residues represented decreasingly smaller fractions of the litter during the succeeding year. Dry weight proportion of leaves in litter was greatest (80.9%) in non-flooded and least (69.1%) in permanently flooded habitats. It was also greatest in small (85.6%) and least in large (64.7%) tree stands. Reproductive structures and mature-fruit fractions in litter were highest in large-tree stands whereas the bud-scale fraction showed no relationship to tree size. Seasonally flooded habitats had the most litterfall, wherein small-, intermediate-, and large-tree stands generated 0.662, 0.882, and 1.128 kg m-2 yr-1, respectively. Dry weight of stems, leaves, bud scales, floral structures, and mature fruit fractions in litter increased as the predominant size of the trees in the stand increased. Total annual litter production was highest during 1999-2000. Leaf fall occurred year-round with maximal amount during April, July, and October. Highest amounts of bud scales and floral structures fell during October-January, which corresponded with flushes of vegetative growth and major flowering events. Overall, melaleuca alone accounted for nearly 99% of the total litterfall dry weight in all habitats and months sampled. The amount of non-melaleuca litter was greater in small-tree stands than in intermediate- or large-tree stands. Litterfall data of this nature will be helpful in detecting changes occurring in melaleuca canopies in response to biological control impact and in prescribing site-specific management strategies. |