Ecosystem dynamics at disturbed and undisturbed sites in North Queensland wet tropical rain forest. III. Nutrient returns to the forest floor through litterfall

1998 ◽  
Vol 14 (2) ◽  
pp. 217-229 ◽  
Author(s):  
JOHN L. HERBOHN ◽  
ROBERT A. CONGDON
Keyword(s):  
Tropical Forests ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Forest Floor ◽  
Dry Weight ◽  
Ecosystem Dynamics ◽  
Wet Season ◽  
Nutrient Return ◽  
Selective Harvesting ◽  
Short Period

The nutrient contents and accessions in litterfall over a period of 3 y are reported for undisturbed areas and at two sites disturbed by selective harvesting in tropical rain forest in North Queensland, Australia. Mean concentrations (mg g&supminus1; dry weight) of nutrients in litterfall ranged from 10 to 12 for nitrogen; 0.33 to 0.43 for phosphorus; 3.6 to 4.3 for potassium; 6.0 to 10.5 for calcium; and 1.7 to 2.6 for magnesium. These concentrations are in the middle to lower part of the spectrum of values recorded for tropical forests. Accessions of nutrients in litterfall (kg ha&supminus1; y&supminus1;) ranged from 59 to 64 N; 1.9 to 2.4 P; 20 to 24 K; 34 to 63 Ca; and 9 to 16 Mg. These rates, particularly for N and P, are among the lowest recorded for tropical forests. There were no consistent between-site differences in total nutrient accessions in small litterfall. In terms of the contribution of litterfall to the accessions of nutrients to the forest floor, this suggests that the logged sites have recovered from the effects of selective harvesting within 25 y. Nutrient accessions at each site were distinctly seasonal, with maximum accessions occurring in the late dry season to late in the wet season. Leaf-fall accounted for the largest proportion of nutrient accessions over the study period, although at certain times accessions in both reproductive material and wood were significant. A cyclone which crossed the coast near the study sites resulted in large nutrient accessions over a short period but had little effect on the total annual accession. A comparison with previous studies of litterfall in Australian tropical rainforests indicates that nutrient return in litterfall is directly related to soil fertility.

Ecosystem dynamics at disturbed and undisturbed sites in north Queensland wet tropical rain forest. II. Litterfall

1993 ◽  
Vol 9 (3) ◽  
pp. 365-380 ◽  
Author(s):  
John L. Herbohn ◽  
Robert A. Congdon
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Ecosystem Dynamics ◽  
Tropical Rain Forests ◽  
Wet Season ◽  
Strong Negative Correlation ◽  
Dominant Component ◽  
Undisturbed Site ◽  
Average Proportion ◽  
Reproductive Material

ABSTRACTRates of litterfall over a period of 3 y at one undisturbed site and two sites disturbed by selective harvesting are reported for a tropical rain forest area in North Queensland, Australia. Litterfall over a period of 18 months is also reported for a further undisturbed site in the same area. No significant differences were found in annual litterfall between the sites, with annual litterfall rates ranging from 5.0 to 6.0 t ha−1 y−1. These rates are considerably lower than those reported for other rain forest areas in Australia, and are within the lower ranges recorded for other tropical rain forests. Litterfall was found to be strongly seasonal at all sites with the maximum falls occurring from the end of the dry season to the end of the wet season. The between year variability of the sites was quite low, with the ratio of maximum to minimum production ranging from 1.05 to 1.20. The average percentages of leaves, wood and reproductive material in litterfall were similar at each site. Leaves were the dominant component of litterfall with the average proportion of the total litterfall ranging from 72% to 76% over the study period at each of the four sites. At certain times, however, the fall of wood and reproductive material was quite significant, comprising as much as 71% and 34% of litterfall respectively. A strong negative correlation was found between the fall of leaves and wood at all sites.

Ecosystem dynamics of disturbed and undisturbed sites in north Queensland wet tropical rain forest. I. Floristic composition, climate and soil chemistry

1993 ◽  
Vol 9 (3) ◽  
pp. 349-363 ◽  
Author(s):  
Robert A. Congdon ◽  
John L. Herbohn
Keyword(s):  
Species Composition ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Soil Chemistry ◽  
Floristic Composition ◽  
Selective Logging ◽  
Ecosystem Dynamics ◽  
Low Fertility ◽  
Available Phosphorus ◽  
Kjeldahl Nitrogen

ABSTRACTThis paper introduces studies of nutrient cycling in disturbed and undisturbed rain forest plots in the upper catchment of Birthday Creek, near Paluma, North Queensland. The catchment is underlain by granite and has soils of comparatively low fertility. Differences between unlogged plots and plots disturbed 25 years previously by selective logging are still apparent. Disturbed plots have soils with higher bulk densities and pH, lower CEC, kjeldahl nitrogen and available phosphorus concentrations, and changed species composition. The data suggest that recovery from selective logging is dependent on soil fertility and intensity of disturbance.

The Landslide Examples Caused by Engineering Construction in Tropical Forests of Hainan

2014 ◽  
Vol 638-640 ◽  
pp. 652-655
Author(s):  
Hui Jiang Liu ◽  
Guang Fan Li ◽  
Yan Rong Li ◽  
Xiao Liang Wang
Keyword(s):  
Tropical Forests ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Engineering Construction ◽  
Water Conservancy

With the development of Hainan tropical rain forest tourism, the constructions of transport and water conservancy facilities are improving in these areas, which will probably cause landslide for changing the topography of the original slope conditions. In that context, a study is performed to find out the reasons for the landslide in tropical forests areas by employing some examples.

Diversity and abundance of understorey plants on active and abandoned nests of leaf-cutting ants (Atta cephalotes) in a Costa Rican rain forest

1998 ◽  
Vol 14 (1) ◽  
pp. 17-26 ◽  
Author(s):  
MARIANA GARRETTSON ◽  
J. F. STETZEL ◽  
BEN S. HALPERN ◽  
DAVID J. HEARN ◽  
BRENDAN T. LUCEY ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Rain Forest ◽  
Forest Floor ◽  
Costa Rican ◽  
Atta Cephalotes ◽  
Rain Forests ◽  
Ant Nests ◽  
Small Height ◽  
Leaf Cutting ◽  
Understorey Plants

Nests of leaf-cutting ants (Hymenoptera: Formicidae: Attini) are abundant disturbances in Neotropical rain forests, and could affect the plant community both while the nests are active and after they are abandoned. We measured the diversity and abundance of understorey plants (>1 m in height) in the area around active and abandoned nests of leaf-cutting ants (Atta cephalotes) at the La Selva Biological Station in Costa Rica. Sampel quadrats on active nests had reduced diversity (number of morphospecies) and abundance of both small (height >10 cm) and large (10 cm–1 m) understorey plants, when compared to the nearby forest floor (3 and 13 m from the nest edge). Abandoned nests had greater diversity and marginally greater abundance of small understorey plants relative to nearby forest; there was no difference in diversity or abundance of large understorey plants. Leaf-cutting ant nests create gaps in the plant understorey when active, but serve as centres of recruitment for small plants after they are abandoned. Thus, like canopy gaps, ant nests could play an important role in recruitment of new individuals and maintenance of plant species diversity in tropical forests.

scholarly journals Asignación de recursos e influencia de los cotiledones en el crecimiento de plántulasde Nectandra ambigens (Blake) C. K. Allen (Lauraceae) en una selva tropical húmeda

2017 ◽  
pp. 5
Author(s):  
Guadalupe Barajas-Guzmán ◽  
Javier Álvarez-Sánchez
Keyword(s):  
Resource Allocation ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Forest Floor ◽  
Forest Canopy ◽  
Regeneration Process ◽  
Stem Biomass ◽  
Advanced Regeneration ◽  
Seedling Biomass ◽  
Parental Resources

In the tropical rain forest, those species having cotyledons, endosperm, or both, which function as storage of parental resources, have a higher probability of surviving as part of the regeneration process. In this study, the influence of cotyledons on the growth of Nectandra ambigens seedlings was analyzed, as well as patterns of resource allocation to shoot, roots and leaves. After germination, seeds where grown under the forest canopy. Five surveys were made at two month intervals. The seedling and cotyledon biomass were significantly different along the time. A negative and significant correlation between cotyledon and seedling biomass was observed. An increase in photosynthetic biomass was measured getting resource from stem biomass and not from roots. This study shows the dependence of Nectandra ambigens seedlings on parental resources for the initial 250 days, which makes them successful in persisting on the forest floor and becoming part of the advanced regeneration.

scholarly journals The impact of European occupation on terrestrial and aquatic ecosystem dynamics in an Australian tropical rain forest

2006 ◽  
Vol 94 (5) ◽  
pp. 987-1002 ◽  
Author(s):  
SIMON G. HABERLE ◽  
JOHN TIBBY ◽  
SOPHIA DIMITRIADIS ◽  
HENK HEIJNIS
Keyword(s):  
Aquatic Ecosystem ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Ecosystem Dynamics ◽  
The Impact

Scatter-hoarding by musky rat-kangaroos, Hypsiprymnodon moschatus, a tropical rain-forest marsupial from Australia: implications for seed dispersal

2003 ◽  
Vol 19 (6) ◽  
pp. 619-627 ◽  
Author(s):  
Andrew J. Dennis
Keyword(s):  
Seed Dispersal ◽  
Tropical Forests ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Convergent Evolution ◽  
Fleshy Fruit ◽  
Scatter Hoarding ◽  
Large Numbers ◽  
The World ◽  
Line Tracking

Tropical forests around the world contain animals that scatter-hoard fruits and seeds but few are known in Australian tropical forests. This study used both direct observation and spool-and-line tracking of simulated fruits to demonstrate that Australia's smallest kangaroos disperse large numbers of rain-forest fruits and seeds. They did so in two ways, either by scatter-hoarding or by carrying them away from the source to devour the flesh before dropping the seed on to the litter surface. The fruits used included a range of fruit types but particularly species with large fleshy fruit. Caches occurred as a single fruit pressed into the soil and covered with litter a mean distance of 17 m (±2.7 SE) and up to 68 m from the source. Musky rat-kangaroos handled up to 2700 fruits ha-1 mo-1 and they dispersed up to 900 fruits ha-1 mo-1 and cached up to 690 fruits ha-1 mo-1. This behaviour is a significant example of convergent evolution, which reflects similar behaviour found in agoutis, acouchies and squirrels on other continents.

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