Seed scatterhoarding by white-tailed rats: consequences for seedling recruitment by an Australian rain forest tree

2001 ◽  
Vol 17 (2) ◽  
pp. 177-189 ◽  
Author(s):  
TAD C. THEIMER
Keyword(s):  
Rain Forest ◽  
Forest Floor ◽  
Seedling Recruitment ◽  
Forest Tree ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Seedling Dynamics ◽  
Avian Frugivore ◽  
Casuarius Casuarius

The role of white-tailed rats (Uromys caudimaculatus) as dispersers of seeds of the Australian tropical rain forest tree Beilschmiedia bancroftii, (Lauraceae) was investigated by following the fates of seeds and seedlings over 2 y. Fruits of this tree are too large to be consumed by any avian frugivore except the southern cassowary (Casuarius casuarius), and the only other native mammal capable of dispersing the seeds is the musky rat kangaroo (Hypsiprimnodon moschatus). However, neither of these species has been documented to disperse the seeds of this tree. During a mast year, white-tailed rats cached seeds an average of 13 m from parent trees in a variety of microsites. Although none of the 61 cached seeds followed in this study survived to germination, comparison of seed, cache and seedling distributions suggested that most seedlings arose from rat-cached seeds. White-tailed rats cached seeds in both mast and non-mast years, but the time seeds remained on the forest floor and in caches was significantly shorter in non-mast years, suggesting that synchronous seed production increases the probability that some caches survive to germination. Because white-tailed rats are the most common and widespread native mammal capable of dispersing large-seeds, this study suggests that they may play an important role in the seed and seedling dynamics of large-seeded tree species in Australian tropical rain forests.

Ants accelerate litter decomposition in a Costa Rican lowland tropical rain forest

2012 ◽  
Vol 28 (5) ◽  
pp. 437-443 ◽  
Author(s):  
Terrence P. McGlynn ◽  
Evan K. Poirson
Keyword(s):  
Mass Loss ◽  
Leaf Litter ◽  
Litter Decomposition ◽  
Rain Forest ◽  
Costa Rican ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Food Web Structure ◽  
Litter Bags ◽  
Lowland Rain Forest

Abstract:The decomposition of leaf litter is governed, in part, by litter invertebrates. In tropical rain forests, ants are dominant predators in the leaf litter and may alter litter decomposition through the action of a top-down control of food web structure. The role of ants in litter decomposition was investigated in a Costa Rican lowland rain forest with two experiments. In a mesocosm experiment, we manipulated ant presence in 50 ambient leaf-litter mesocosms. In a litterbag gradient experiment, Cecropia obtusifolia litter was used to measure decomposition rate constants across gradients in nutrients, ant density and richness, with 27 separate litterbag treatments for total arthropod exclusion or partial arthropod exclusion. After 2 mo, mass loss in mesocosms containing ants was 30.9%, significantly greater than the 23.5% mass loss in mesocosms without ants. In the litter bags with all arthropods excluded, decomposition was best accounted by the carbon: phosphorus content of soil (r2 = 0.41). In litter bags permitting smaller arthropods but excluding ants, decomposition was best explained by the local biomass of ants in the vicinity of the litter bags (r2 = 0.50). Once the microarthropod prey of ants are permitted to enter litterbags, the biomass of ants near the litterbags overtakes soil chemistry as the regulator of decomposition. In concert, these results support a working hypothesis that litter-dwelling ants are responsible for accelerating litter decomposition in lowland tropical rain forests.

scholarly journals LINGKUNGAN VEGETASI SITUS PERCANDIAN PADANG LAWAS DAN TUMBUHAN BALAKA

2011 ◽  
Vol 31 (1) ◽  
pp. 31-44
Author(s):  
Arfian Arfian
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Wild Plant ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Open Spaces ◽  
Lowland Tropical Rain Forest ◽  
Plant Families ◽  
High Level

Based on the results of research on the vegetation around Padang Lawas Temples, Padang Lawas Regency, North Sumatera Province, can be known that Padang Lawas Temple sites are located in vegetation environment of lowland tropical rain forest with a high level diversity of plant families, one of those plant families is Euphorbiaceae with one of its species, Phylanthus emlica. L(Balaka). Phylanthus emlica is a type wild plant that grows open spaces in lowland tropical rain forests. Observing its life characteristic and its habitat, then Balaka plant (Phylanthus emlica) in Padang Lawas Temples’ yards was not planted in purpose planted but grows naturally. Balaka plant (Phylanthus emlica) has different name in every area. In Melayu, this plant is known as malaka. In Minangkabau known as balaka, in Sunda known as malaka and in Java, this plant is known as Kemloko, meanwhile in Madura and Bali this plant is called mlakah ,and karsinta in Flores (NTT)

scholarly journals Investigations on the poisoning of tropical rain-forests for land-reclamation and wood-exploitation purposes.

1961 ◽  
Vol 9 (1) ◽  
pp. 17-26
Author(s):  
G.H. Morhaus ◽  
L.F. Van Santen Kolff
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Land Reclamation ◽  
Diesel Oil ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Slight Effect ◽  
Cheap Method ◽  
Methods Of Application

Reports selective tree-poisoning trials in Sumatra in 1955-57, using various concentrations of Na arsenite, trioxone, NH4 sulphamate, and 2, 4, 5-T, and various methods of application. Some 17 species were poisoned [but no distinction is made between species in the evaluation of the results]. It was found that NH4 sulphamate was virtually useless, and that trioxone and 2, 4, 5-T in water had only a slight effect, and were still unsatisfactory in diesel oil; they were more effective against smaller trees. Na arsenite was the best, especially at stronger concentrations. It is concluded that selective poisoning makes possible the easy exploitation of suitable timbers, and provides a quick and cheap method of clearance, in which less tractor time is needed and damage to the soil is slight. KEYWORDS: trees \ poisoning \ control \ trees \ poisoning \ control \ tropical rain forest \ Silviculture \ Tending \ stands and trees \ herbicides \ 2, 4-D \ and 2, 4, 5 T \ herbicides \ Ammate \ herbicides \ Na arsenite (Abstract retrieved from CAB Abstracts by CABI’s permission)

Preservation Paradigms and Tropical Rain Forests

Last Stand ◽  
1997 ◽  
Author(s):  
Randall A. Kramer ◽  
Carel P. van Schaik
Keyword(s):  
Protected Areas ◽  
Rain Forest ◽  
Past Century ◽  
Strict Sense ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
The Past ◽  
Living Organisms ◽  
The Developed Countries ◽  
Definition Of

Tropical rain forests are disappearing rapidly as a result of increasing human encroachment. During the past century, tropical rain forests have been reduced to about half of their original area. And the rate of deforestation is accelerating, fueled by population growth in developing countries and resource demands in the developed countries. The remaining forests are subject to increasingly intensive human use. Deforestation, fragmentation, and exploitation cause a plethora of problems, including soil erosion; siltation of rivers, lakes, and estuaries; increased flooding and droughts; release of carbon dioxide and other greenhouse gases into the atmosphere; and loss of species. In recent years, these problems have become the subject of international concern. This book focuses on the loss of biodiversity in tropical rain forests and on the role of protected areas in stemming the loss. This chapter examines the meaning of biodiversity and the history of the park movement in the tropics. What began as protection of habitat through the exclusion of people has transformed into sustainable use of biological resources. This new emphasis provides local control of important resources and greater income, but does it conserve habitat and species? We will argue that a renewed focus on protected areas as the primary storehouse of biodiversity is needed. We will also make the case for a focus on the tropical rain forest biome and will conclude with an overview of the rest of the book. In its strict sense, biodiversity refers to the “variety and variability among living organisms and the ecological complexes in which they occur” (Office of Technology Assessment, U.S. Congress, 1987:3). This definition can be extended both downward to cover genetic variability within a species and upward to include habitat and ecosystem diversity. practical terms, however, biodiversity is most profitably expressed as species diversity (weighted for rarity, endemism, and taxonomic distinctiveness, if necessary) at the landscape level (see chapter 6). We adopt this definition of biodiversity. During the past few years, attempts to link rain forest protection with sustainable development have led to a noticeable expansion of the meaning of the phrase “biodiversity conservation.”

Do dipterocarp seedlings really partition tropical rain forest gaps?

1992 ◽  
Vol 335 (1275) ◽  
pp. 369-378 ◽  
Keyword(s):  
Rain Forest ◽  
Seedling Survival ◽  
Canopy Gaps ◽  
Forest Recovery ◽  
Canopy Openness ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Regeneration Dynamics ◽  
Closed Forest ◽  
Survival And Growth

The theory of gap regeneration dynamics proposes that different species of tree partition canopy gaps because they are preferentially adapted to a particular gap size class. A variety of gap sizes would therefore favour the regeneration of a range of species. The theory has been used to explain the extraordinarily high tree species diversity of tropical rain forests. A test was mounted in lowland evergreen dipterocarp rain forest in the Danum Valley, Sabah, East Malaysia by the creation of ten, artificial canopy gaps ranging in size from 10 m 2 to 1500 m 2 (6 to 30% canopy openness). The responses of established populations of seedlings of three dipterocarp species ( Hopea nervosa , Parashorea malaanonan and Shorea johorensis ) with contrasting silvicultural reputations were monitored for 40 months in these gaps and under closed forest. There were significant differences in survival and growth under closed forest between these three species. However, in gaps, the most important determinant of seedling survival and growth was seedling size at the time of gap creation, regardless of species. An ability to persist for long periods under closed forest and slowly accumulate growth may bestow an enormous size advantage on seedlings when gaps occur. Generalizations on the regeneration dynamics of dipterocarp rain forests need to be modified in the light of this result. Further observations for several years are important to see whether forest recovery eventually converges on predictions from the original paradigm.

Predation on exposed and leaf-rolling artificial caterpillars in tropical forests of Papua New Guinea

2012 ◽  
Vol 28 (4) ◽  
pp. 331-341 ◽  
Author(s):  
Katerina Tvardikova ◽  
Vojtech Novotny
Keyword(s):  
Natural Enemies ◽  
Rain Forest ◽  
Secondary Forest ◽  
Primary Forest ◽  
Secondary Forests ◽  
Forest Fragments ◽  
Leaf Rolling ◽  
Forest Fragment ◽  
Tropical Rain Forests ◽  
Rain Forests

Abstract:Although predation is generally seen as one of the key factors determining the abundance and composition of insect herbivore communities in tropical rain forests, quantitative estimates of predation pressure in rain-forest habitats remain rare. We compared incidence of attacks of different natural enemies on semi-concealed and exposed caterpillars (Lepidoptera) in lowland and montane tropical rain forests, using plasticine models of caterpillars. We recorded attacks on caterpillars in four habitats: primary forest, secondary forest and forest fragment in lowlands (200 m asl), and montane primary forest (1700 m asl). We used 300 exposed and 300 semi-concealed caterpillars daily, and conducted the experiment for 6 d in every habitat. Daily incidence of attacks was higher on exposed caterpillars (4.95%) than on semi-concealed (leaf-rolling) caterpillars (2.99%). Attack pressure of natural enemies differed also among habitats. In the lowlands, continuous primary and secondary forests had similar daily incidence of attacks (2.39% and 2.36%) which was however lower than that found in a primary forest fragment (4.62%). This difference was caused by higher incidence of attacks by birds, ants and wasps in the forest fragment. The most important predators were birds in montane rain forests (61.9% of identified attacks), but insect predators, mostly ants, in the lowlands (58.3% of identified attacks). These results suggest that rapid decrease in the abundance of ants with altitude may be compensated by increased importance of birds as predators in montane forests. Further, it suggests that small rain-forest fragments may suffer from disproportionately high pressure from natural enemies, with potentially serious consequences for survival of their herbivorous communities.

scholarly journals Ficus insipida subsp. insipida (Moraceae) reveals the role of ecology in the phylogeography of widespread Neotropical rain forest tree species

2014 ◽  
Vol 41 (9) ◽  
pp. 1697-1709 ◽  
Author(s):  
Eurídice N. Honorio Coronado ◽  
Kyle G. Dexter ◽  
Monica F. Poelchau ◽  
Peter M. Hollingsworth ◽  
Oliver L. Phillips ◽  
...  
Keyword(s):  
Tree Species ◽  
Rain Forest ◽  
Forest Tree ◽  
Forest Tree Species ◽  
Neotropical Rain Forest

Plant secondary compounds in the canopy and understorey of a tropical rain forest in Gabon

2001 ◽  
Vol 17 (3) ◽  
pp. 477-481 ◽  
Author(s):  
KELSEY DOWNUM ◽  
DAVID LEE ◽  
FRANCIS HALLÉ ◽  
MARTIN QUIRKE ◽  
NEIL TOWERS
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Secondary Compounds ◽  
Ecological Research ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Plant Secondary Compounds ◽  
Spatial Exploration

Given their difficulty of access, the canopies of tropical rain forests are considered a last frontier of biological/ecological research (Lowman & Nadkarni 1995). Climbing techniques are arduous and do not reach the tips of branches; towers, cranes and walkways limit the spatial exploration of the forest.

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