Rain Forest Regeneration Research Articles

Pine plantations in savanna areas can alter vegetation dynamics facilitating tropical rainforest regeneration at the expense of savannas: a case study in Southeast Mexico

Pine plantations in savanna areas can alter vegetation dynamics facilitating tropical rainforest regeneration at the expense of savannas: a case study in Southeast Mexico

The effects of the invasive species, Lantana camara, on regeneration of an African rainforest

AbstractInvasive plants adversely affect native communities by altering ecosystem function and disrupting natural regeneration. We investigate the effect of invasive Lantana camara L. (Verbenaceae) on forest regeneration in Kibale National Park, Uganda. We appraise the efficacy of cutting and uprooting Lantana for promoting native tree recruitment. Sample plots comprised three types: (i) currently invaded by Lantana; (ii) cleared of Lantana and now managed; and (iii) forest reference plots uninvaded by Lantana. Tree species numbering 51, 19 shrubs, and 17 herb species were identified. Lantana reduced tree, shrub, and herb cover and diversity, and suppressed tree regeneration. The short‐term management of Lantana did not promote tree establishment. The tree community in cleared areas was not converging on uninvaded adjacent forest. Lantana is known to allelopathically suppress tree seedling establishment, but even at sites cleared of Lantana, tree species recruitment was poor. While insufficient time may have passed for tree recruitment, we argue that an increase in shrub and herb cover and diversity arrested forest tree regeneration. Sustained follow‐up clearing of dense secondary shrubs and herbs and resprouted L. camara in cleared areas is key to ensuring long‐term recovery of the forest tree community.

Tree recruitment failure in old‐growth forest patches across human‐modified rainforests

Abstract Land‐use change threatens biodiversity in tropical landscapes, but its impact on rainforest regeneration remains poorly known. In fact, the landscape‐scale patterns driving the diversity of regenerating plants within forest fragments have been rarely explored, and we are uncertain whether such drivers vary across regions with different land‐use change patterns. We assessed the effect of landscape composition (forest cover and matrix openness) and configuration (forest patch density) on species diversity of sapling assemblages (trees ≥30 cm height and <1 cm diameter) in old‐growth forest fragments from three Mexican rainforest regions with different disturbance levels (n = 20 landscapes per region). We separately assessed old‐growth forest specialists (OGS) and forest generalist (FG) species to test the hypotheses that: (a) OGS species show recruitment limitation (‘loser’ species), and can therefore be negatively impacted by landscape changes, especially by forest loss and matrix openness in more deforested regions; and (b) FG species can regenerate and even proliferate in more disturbed landscapes (‘winner’ species). We recorded ~24,000 plants from 415 species. Landscape composition showed stronger effects than landscape configuration. The diversity of OGS species generally decreased in more deforested landscapes dominated by open matrices, and FG species followed the opposite response, especially in the regions with high‐to‐intermediate degree of disturbance. Overall, forest fragmentation (patch density) showed weak or no effects on species diversity, especially after controlling for forest cover effects (i.e. fragmentation per se). In contrast to the fragmentation threshold hypothesis, the effect of fragmentation was independent of the regional context. Moreover, FG species were affected by landscape attributes operating at larger scales than OGS species. Synthesis. Our findings support our hypotheses, and suggest that forest loss and matrix openness, not fragmentation per se, can cause the recruitment failure of tree assemblages in highly deforested rainforests. This can be related to source and dispersal limitation in more deforested landscapes with treeless matrices. Therefore, to promote the regenerative potential (resilience) of forest patches in human‐modified tropical landscapes, conservation programs should focus on preventing forest loss (even the smallest forest patches) and improving matrix quality with treed elements, particularly in highly deforested tropical regions.

Tebuconazole-induced toxicity and the protective effect of Ficus carica extract in Neotropical fruit-eating bats

Tebuconazole (TEB) is a triazole fungicide widely used in agriculture known to cause metabolic and endocrine disorders in mammals. Several plant extracts have shown to be beneficial against pesticide effects due to their hepatoprotective, antioxidant and anti-inflammatory properties. As fruit bats play a critical role in rainforest regeneration and are constantly exposed to pesticides, we aimed at evaluating TEB-induced toxicity and the possible protective effect of the Ficus carica plant extract in Neotropical fruit-eating bats (Artibeus lituratus). Bats were captured and assigned to 4 experimental groups, offered: 1) CTL (n = 6): papaya; 2) DMSO (n = 6): papaya treated with 1.25% dimethyl sulfoxide (DMSO); 3) TEB (n = 6): papaya treated with tebuconazole (commercial formulation) 0.1%; and 4) TEBFC (n = 6): papaya treated with tebuconazole 0.1% and Ficus carica extract (20%) in DMSO (1.25%). After seven days of exposure, TEB bats showed increased lipid peroxidation, increased superoxide dismutase (SOD) and catalase (CAT) activities, vascular congestion and inflammatory infiltrate in the liver, and increased serum transaminase enzyme activities. We found the same alterations in oxidative stress parameters in the breast muscles of TEB-exposed bats. In the testes, all oxidative stress markers were increased in TEB bats and corroborate findings of histopathological and increased serum testosterone levels observed following TEB exposure. The co-administration of the fungicide with the F. carica plant extract attenuated most oxidative stress markers in exposed bats’ liver and testes and decreased liver damage, but failed to revert the steroid imbalance caused by the fungicide exposure.

Enhancing bird-mediated seed dispersal to increase rainforest regeneration in disused pasture – A restoration experiment

Frugivorous birds are important seed dispersers but are infrequent visitors to pasture. Therefore, the recruitment of rainforest trees into disused pasture is often limited by dispersal. We studied potential seed sources, seed-dispersing birds, seed rain and seedling recruitment in an experimental management project that aimed to catalyse rainforest regeneration adjacent to old-growth forest in north-eastern Australia. To attract birds, nine semi-natural perches and water basins were installed in each of three 0.64 ha experimental plots, concurrent with herbicide control of pasture grasses. Despite a diverse avian seed-disperser community in the adjacent forest, only three species visited the plots. However, the presence of water increased seed deposition. Water basins collected twelve times as many native tree seeds as mesh seed traps (a 24-fold increase in seed deposition per unit area), including more large seeds (≥10 mm), and more species, especially of bird-dispersed forest trees. This was due to the large-gaped Pied Currawong (Strepera graculina) that deposited large seeds beneath the perches, when using water to regurgitate seeds. Deposition of large native forest tree seeds was also enhanced under perches positioned close to an already established tree or large shrub, highlighting an important indirect effect of pasture trees. Such pasture trees can themselves be effective regeneration nuclei, and their function improved by actions to suppress pasture growth and encourage dispersers. However, in this study, these interventions were not sufficient to fully mitigate barriers to rainforest regeneration. Although seed deposition was enhanced by the presence of water, semi-natural perches and pasture trees, recruited seedlings in the plots were not representative of the seed deposited. Instead they were dominated by a subset of small-diaspore, pioneer species. To further test the potential for semi-natural perches, water and pasture suppression to increase rainforest regeneration in disused pasture, requires testing of water source designs and carefully designed experimental restoration to examine dispersal and other regeneration barriers.

Are microbial activity and arbuscular mycorrhizal fungal community influenced by regeneration stages? A case study in Southern Brazil coastal Atlantic Rain Forest

Aiming to describe coastal Atlantic Rain Forest (ARF) regeneration dynamics, we evaluated attributes linked to soil biota and mycorrhizal symbiosis in two coastal ARF sites in Florianópolis, Southern Brazil. In each site, we selected forest transects in early regeneration (ER) and advanced regeneration (AR) stages, i.e., about 20 and 50 years without agricultural use, respectively. Soil total organic carbon (TOC) was higher in AR than in ER stage. Soil microbial biomass carbon (MBC) varied between sites and was higher in the AR than in the ER stage. Basal respiration and qCO2 rates differed between sites and were, respectively, higher and lower in advanced regeneration stage areas. Arbuscular mycorrhizal (AM) root colonization and AM fungal spore density were higher in the ER stage, with no difference between sites. Principal Component Analysis (PCA) for correlation between soil microbiological and chemical attributes showed that the variables with the most influence on sample separation for the first component were total spore number, soil MBC, root mycorrhizal colonization, and soil TOC. Soil pH, available P, and qCO2 had the highest influence on the second component. This analysis separated samples by regeneration stage, and sites differed only in AR stage. PCR-DGGE analysis on DNA extracted from soil samples showed that AMF community structure differed more between sites than between regeneration stages.

Arbuscular mycorrhizal fungal communities in tropical rain forest are resilient to slash-and-burn agriculture

Abstract:Certain forestry and agricultural practices are known to affect arbuscular mycorrhizal (AM) fungal communities, but the effects of deforestation – including slash-and-burn management and other more severe disturbances – in tropical rain forests are poorly understood. We addressed the effects of anthropogenic disturbance on rain-forest AM fungal communities in French Guiana, by comparing mature tropical rain forest, slash-and-burn (5 y old) and clearcut areas (8 y old). A total of 36 soil samples were collected in six plots and sequenced using a high throughput 454-pyrosequencing platform. A total of 32649 sequences from 103 AM fungal virtual taxa (VT) were recorded. Whereas alpha diversity of AM fungi did not decrease due to land-use intensification, with average richness ranging from 17 to 21 taxa per plot, beta diversity (average distance to multivariate centroid) dropped by 28% from 0.46 in rain forest to 0.33 under clearcutting. AM fungal community composition was correlated with land use and soil chemical properties. Clearcut areas were characterized by the more frequent occurrence of specialist AM fungi, compared with mature forest or slash-and-burn areas. Specifically, clearcuts contained the highest proportions of VT that were geographic (21%), habitat (31%), abundance (97%) or host (97%) specialists based on VT metadata contained in the MaarjAM database. This suggests that certain AM fungi with narrow ecological niches have traits that allow them to exploit conditions of severe disturbance. In conclusion, slash-and-burn management appears to allow diverse AM fungal communities to persist, and may favour regeneration of tropical rain forest after abandonment. More severe disturbance in the form of clearcutting resulted in marked changes in AM fungal communities.

How Much Potential Biodiversity and Conservation Value Can a Regenerating Rainforest Provide? A ‘Best-Case Scenario’ Approach from the Peruvian Amazon

The structure and underlying functions of the majority of the world's tropical forests have been disrupted by human impacts, but the potential biodiversity and conservation value of regenerating forests is still debated. One review suggests that on average, regenerating tropical forests hold 57% (±2.6%) of primary forest species richness, raising doubt about a viable second chance to conserve biodiversity through rainforest regeneration. Average values, however, likely underestimate the potential benefit to biodiversity and conservation because they are drawn from many studies of short-term regeneration and studies confounded by ongoing human disturbance. We suggest that the true potential biodiversity and conservation value of regenerating rainforest could be better assessed in the absence of such factors and present a multi-taxa case study of faunal biodiversity in regenerating tropical forest in lowland Amazonia. We found that biodiversity of this regenerating site was higher than might have been expected, reaching 87% (±3.5%) of primary forest alpha diversity and an average of 83% (±6.7) of species estimated to have occurred in the region before disturbance. Further, the regenerating forest held 37 species of special conservation concern, representing 88% of species of highest conservation importance predicted to exist in primary forest from the region. We conclude that this specific regenerating rainforest has high biodiversity and conservation value, and that whilst preserving primary forest is essential, our results suggest that under a best-case scenario of effective conservation management, high levels of biodiversity can return to heavily disturbed tropical forest ecosystems.

Effect of reduced-impact logging on seedling recruitment in a neotropical forest

Seedling growth and survival are critical for tropical rainforest regeneration. Alterations to natural disturbance regimes, such as those brought about by logging, have the potential to shift relative species abundances and the community composition of forests, resulting in population declines for commercially valuable species. Timber operations therefore need to minimise such changes if long-term sustainability is to be achieved within the industry. Reduced-impact logging (RIL) has been promoted widely as an alternative management strategy to conventional selective logging, as it employs practices that decrease the negative impacts of logging within forests. However, the long-term sustainability of RIL, including the influence it has on the regeneration of species targeted for timber extraction, is still uncertain. Here we undertake a comparative study in Iwokrama forest, Guyana, examining seedling densities of four commercially valuable and two pioneer tree species in unlogged, 1.5years and 4.5years postharvest forest plots to ascertain how seedling regeneration is effected by RIL. We find that RIL had either a neutral or positive impact on the density of seedlings of timber species when compared to unlogged forest, with pioneer species densities remaining rare. We conclude that the forestry practices associated with RIL have little effect on the natural regeneration rates of key commercially valuable tree species in logged neotropical forests.

Second Growth: The Promise of Tropical Rain Forest Regeneration in the Age of Deforestation

Second Growth: The Promise of Tropical Rain Forest Regeneration in the Age of Deforestation

Amazon Rain Forest Succession: Stochasticity or Land-Use Legacy?

Land-use practices can dramatically shift the trajectories of rain forest recovery. In a 25-year study, Amazon rain forest regenerated following deforestation as long as seed availability and seedling recruitment were not interrupted. In contrast, rain forest converted to cattle pastures via cutting and burning prior to abandonment diverted succession, leading to highly simplified stands dominated by a single genus. Annual fires eliminated seedlings, saplings, coppice, and seeds in the soil, except for several Vismia species. Once established, Vismia regenerated by continual resprouting and resisted the establishment of other rain forest species, especially the normal suite of pioneers. Through time, succession both in abandoned clearcuts and pastures increased in stem density and biomass; however, species accumulation and ecosystem services were limited in pastures when compared with those in abandoned clearcuts. Therefore, prescribed burning to maintain pastureland leaves a legacy that is not readily extinguished, whereas abandoning clearcuts engenders an accelerated rain forest regeneration.

Charcoal-inferred Holocene fire and vegetation history linked to drought periods in the Democratic Republic of Congo.

The impact of Holocene drought events on the presumably stable Central African rainforest remains largely unexplored, in particular the significance of fire. High-quality sedimentary archives are scarce, and palynological records mostly integrate over large regional scales subject to different fire regimes. Here, we demonstrate a direct temporal link between Holocene droughts, palaeofire and vegetation change within present-day Central African rainforest, using records of identified charcoal fragments extracted from soil in the southern Mayumbe forest (Democratic Republic of Congo). We find three distinct periods of local palaeofire occurrence: 7.8-6.8ka BP, 2.3-1.5ka BP, 0.8ka BP - present. These periods are linked to well-known Holocene drought anomalies: the 8.2ka BP event, the 3rd millennium BP rainforest crisis and the Mediaeval Climate Anomaly. During and after these Holocene droughts, the Central African rainforest landscape was characterized by a fragmented pattern with fire-prone open patches. Some fires occurred during the drought anomalies although most fires seem to lag behind them, which suggests that the open patches remained fire-prone after the actual climate anomalies. Charcoal identifications indicate that mature rainforest patches did persist through the Early to Mid-Holocene climatic transition, the subsequent Holocene thermal optimum and the third millennium BP rainforest crisis, until 0.8ka BP. However, disturbance and fragmentation were probably more prominent near the boundary of the southern Mayumbe forest. Furthermore, the dominance of pioneer and woodland savanna taxa in younger charcoal assemblages indicates that rainforest regeneration was hampered by increasingly severe drought conditions after 0.8ka BP. These results support the notion of a dynamic forest ecosystem at multicentury time scales across the Central African rainforest.

Restoration of rain forest beneath pine plantations: A relay floristic model with special application to tropical South Asia

In the wet forest regions of southwest Sri Lanka and the Western Ghats, India, Pinus caribaea was a common tree species for reforestation on public lands that were originally cleared of native forest for agriculture but subsequently succeeded to fire tolerant grasses and ferns. Much of this reforestation occurred during the 1970s and 1980s. The ecological literature suggests that in many temperate broadleaf forest regions pine is an important component of early succession on old fields, beneath which second growth hardwood can establish and eventually dominate. More recent studies have demonstrated the establishment of native rain forest regeneration beneath a variety of exotic tree plantations. We review nearly twenty-five years of research on this topic for South Asia through a series of studies done in southwest Sri Lanka. Results demonstrate that native species recruitment of both pioneers and site generalist late-successional trees grow well beneath exotic pine plantations. Diversity and density increase from plantation interior to edge. Protection from groundstory fire is the single most important component of promoting regeneration recruitment beneath pine. Establishing late-successional site and dispersal restricted species requires planting beneath pine rather than reliance on natural establishment. Best establishment and growth occur in openings where rows of canopy pine have been removed. Species considered for planting comprise the major late-successional canopy tree species of the forest in the genera Dipterocarpus, Shorea (Dipterocarpaceae) and Mesua (Clusiaceae). Native species that produce non-timber forest products (NTFP) need to be planted with best results in canopy openings. The most valuable NTFP’s comprise a sugar palm (Caryota urens), rattan (Calamus spp.) and a medicinal liana (Coscinium fenestratum). Financial analyses reveal that pine plantations that are enrichment planted and cultivated with rain forest timber and non-timber species can provide superior economic benefits as compared to land cultivated singly for tea.

NATURAL REGENeRATION IN KEKILLA FERNLANDS IN THE PERIPHERY OF SINHARAJA WORLD HERITAGE SITE

In tropical moist climate Dicranopteris !inearis (Kekilla) fernland can develop as a resultof rain forest clearance followed by frequent burning. In Sri Lanka D. linearis fernlandsare capable of suppressing the natural regeneration of rain forest. Sinha raja WorldHeritage Site is one of the least disturbed and biologically unique lowland rain forest nowremaining in Sri Lanka. Some areas of the periphery of Sinharaja are covered with Dlenearis fern. Natural regeneration dynamics of soil seed banks need to be studied as apossible source of regeneration for forest restoration in these fern lands.This study was carried out to understand the natural regeneration of soil seed bank inKekilla fernland with reference to surface soil disturbance and trophographic levels in theperiphery of Sinharaja World Heritage Site.Three sites of Kekilla fernlands were selected for the study. Two surface soil disturbancetreatments were applied to each site. The first treatment (Root Removal) was applied at thebeginning of the study. The next treatment (Till) was applied to each site after six monthsfrom the first treatment. Seeds in the soil were allowed to germinate and seedlings werecounted once in two weeks during the first four months. After four months the seedlingswere recorded once a month. Transectswere laid out in each site to understand the floristiccomposition in surrounding vegetation of D. lenearis fernlands.Seedlings of 35 taxa were identified during the period of study. The study revealed thatboth soil disturbance treatments can facilitate the establishment of herbs, shrubs and treesin the fern land dominated by D. lenearis. Results showed that herbs, shrubs, grassesrepresented the greater proportions of seedling recruitment than pioneer trees. Seedlings ofprimary forest species were not existentSpecies composition of soil seed bank ill three-tophographic positions was not significantlydifferent. Numbers of species and seedling density were greatest in root removal treatment.Seedlings of primary forest species found in surrounding vegetation were not regeneratingin the plots studied. Only few pioneer tree seedlings were found in the plots, representingsurrounding vegetation of Kekilla fernland.

Frugivory and Seed Dispersal by Northern Pigtailed Macaques (Macaca leonina), in Thailand

Tropical rain forest conservation requires a good understanding of plant–animal interactions. Seed dispersal provides a means for plant seeds to escape competition and density-dependent seed predators and pathogens and to colonize new habitats. This makes the role and effectiveness of frugivorous species in the seed dispersal process an important topic. Northern pigtailed macaques (Macaca leonina) may be effective seed dispersers because they have a diverse diet and process seeds in several ways (swallowing, spitting out, or dropping them). To investigate the seed dispersal effectiveness of a habituated group of pigtailed macaques in Khao Yai National Park, Thailand, we examined seed dispersal quantity (number of fruit species eaten, proportion in the diet, number of feces containing seeds, and number of seeds processed) and quality (processing methods used, seed viability and germination success, habitat type and distance from parent tree for the deposited seeds, and dispersal patterns) via focal and scan sampling, seed collection, and germination tests. We found thousands of seeds per feces, including seeds up to 58 mm in length and from 88 fruit species. Importantly, the macaques dispersed seeds from primary to secondary forests, via swallowing, spitting, and dropping. Of 21 species, the effect of swallowing and spitting was positive for two species (i.e., processed seeds had a higher % germination and % viability than control seeds), neutral for 13 species (no difference in % germination or viability), and negative (processed seeds had lower % germination and viability) for five species. For the final species, the effect was neutral for spat-out seeds but negative for swallowed seeds. We conclude that macaques are effective seed dispersers in both quantitative and qualitative terms and that they are of potential importance for tropical rain forest regeneration.

Seed dispersal patterns in two closely related howler monkey species (<i>Alouatta palliata</i> and <i>A. pigra</i>): a preliminary report of differences in fruit consumption, traveling behavior, and associated dung beetle assemblages

Two-phased seed dispersal by primates and dung beetles is crucial for tropical rainforest regeneration. Two species of howler monkey exist in the tropical rainforests of southern Mexico: the mantled howler monkey (Alouatta palliata), and the black howler monkey (A. pigra). Differences between these species in foraging and traveling behavior, as well as associated dung beetle assemblages, may influence seed dispersal patterns. In this paper we present the results of a preliminary four-month study comparing the above aspects between a group of A. palliata (N = 15) in Los Tuxtlas, Veracruz and a group of A. pigra (N = 7) in Palenque National Park, Chiapas, Mexico. We observed each group in alternating months using focal sampling, fecal examination, and trapping of dung beetles. Results showed that the A. palliata group consumed more mature fruit, but both groups dispersed similar numbers of seeds over the study period (ca. 13,000 seeds). The total number of seed species collected from the feces of the A. palliata group was lower than for the A. pigra group (13 vs. 31 species). The A. palliata group had a larger home range (33 vs. 6.25 ha) and average day range (202 vs. 126 m). More dung beetles from more species were associated with the A. palliata group (357 v. 99 beetles, 16 v. 8 species). The A. palliata group attracted more ball-rolling dung beetles (75.1% of total), while the A. pigra group attracted more burrowers (80.8% of total). Our results suggest important differences between black and mantled howler monkeys of southern Mexico as seed dispersers and highlight the need to consider foraging and ranging patterns, as well as associated secondary dispersers, when assessing seed dispersal by primates.

Seasonal Variation in Seed Dispersal by Tamarins Alters Seed Rain in a Secondary Rain Forest

Reduced dispersal of large seeds into degraded areas is one of the major factors limiting rain forest regeneration, as many seed dispersers capable of transporting large seeds avoid these sites with a limited forest cover. However, the small size of tamarins allows them to use small trees, and hence to disperse seeds into young secondary forests. Seasonal variations in diet and home range use might modify their contribution to forest regeneration through an impact on the seed rain. For a 2-yr period, we followed a mixed-species group of tamarins in Peru to determine how their role as seed dispersers in a 9-yr-old secondary-growth forest varied across seasons. These tamarins dispersed small to large seeds of 166 tree species, 63 of which were into a degraded area. Tamarins’ efficiency in dispersing seeds from primary to secondary forest varied across seasons. During the late wet season, high dietary diversity and long forays in secondary forest allowed them to disperse large seeds involved in later stages of regeneration. This occurred precisely when tamarins spent a more equal amount of time eating a high diversity of fruit species in primary forest and pioneer species in secondary forest. We hypothesized that well-balanced fruit availability induced the movement of seed dispersers between these 2 habitats. The noteworthy number of large-seeded plant species dispersed by such small primates suggests that tamarins play an important, but previously neglected, role in the regeneration and maintenance of forest structure.Electronic supplementary materialThe online version of this article (doi:10.1007/s10764-010-9413-7) contains supplementary material, which is available to authorized users.

Benefits from ecological study methods to taxonomy of enchytraeids in southern Mata Atlântica

The objective of this work was to determine how taxonomy benefited from the ecological quantitative and site-based sampling methods in enchytraeids studies. Enchytraeids (small relatives of earthworms) were sampled in different phases of rain forest regeneration in the southern Mata Atlântica in Paraná, Brazil. The research combined ecological and taxonomic work, because enchytraeids are poorly studied and difficult to identify, and many new species were expected. The provision of large numbers of specimens enabled the test of species diagnoses by investigating the ranges of character variations in a larger series of specimens. Simplified species diagnoses adapted to the local conditions that allowed the identification of all specimens, juveniles included, were developed. Key characters and character states are presented for the three genera: Achaeta, Hemienchytraeus and Guaranidrilus. Among several new species, a rare species, possibly a remnant of the autochthonous forest fauna, was found and described.

Reduced dispersal of native plant species as a consequence of the reduced abundance of frugivore species in fragmented rainforest

Frugivorous animals disperse the seeds of the majority of rainforest plant species and hence play a key role in the trajectory of rainforest regeneration. This study investigated whether changes in the species composition of the frugivore community in fragmented rainforest in subtropical Australia is likely to impact the dispersal of native plant species. The potential of frugivorous bird and bat species to disperse the seeds of plant species in fragmented rainforest was assessed using published dietary information together with field surveys of frugivore abundance within intact forest, forest fragments and patches of regrowth. Frugivore species with reduced abundance in fragmented rainforest were the only known dispersers of 27 of the 221 native plant species in the data set (12% of species). These frugivore species were also major dispersers of plant species producing fruits wider than 10 mm and species from the families Rubiaceae, Lauraceae, Myrtaceae, Meliaceae, Lamiaceae and Vitaceae. Except for Rubiaceae, these plant taxa are also potentially dispersed by two of the frugivore species that were widespread in fragmented rainforest, Lopholaimus antarcticus and Ptilonorhynchus violaceus, although dispersal rates are likely to be lower in fragmented than in extensive rainforest. Consistent with other regions, large-seeded plants are susceptible to reduced dispersal in fragmented rainforest in subtropical Australia. However, we predict a smaller deficit in seed dispersal in fragmented forests than has been reported from other regions, due to factors such as functional overlap among frugivore species, the ability of many Australian rainforest vertebrates to persist in fragmented rainforest, and a lack of hunting in these forests. Nevertheless, rainforest fragmentation has reduced the abundance of a suite of frugivorous rainforest fauna, which in turn is likely to reduce the dispersal of a certain plant taxa and may alter patterns of plant regeneration in subtropical Australian rainforest fragments.

Monitoring and assessment of restoration of a rainforest remnant at Wingham Brush, NSW

Abstract Wingham Brush is a 9-ha remnant of lowland subtropical rainforest, on mid-north coast New South Wales, Australia, with high floristic diversity (about 200 species, more than 70 endemic trees and 27 endemic vines). A history of disturbance, environmental mismanagement and flooding from the Manning River resulted in many exotic species vigorously invading the rainforest. By the late 1970s weeds blanketed large sections of the forest, preventing regeneration of native species and destroying the canopy. By 1978 rainforest ecologists thought it ‘doubtful whether the rainforest could be saved from extinction.’ In 1980 a restoration program funded by the National Trust of Australia (NSW), used the Bradley Method of bush regeneration. However, this method did not consider the unique character of the rainforest community, which required the highest priority to be restoring the canopy. The National Herbarium of New South Wales became involved in 1984 as an independent agency to monitor the progress of the regeneration and assess the techniques being used, in particular the use of glyphosate. Monitoring provided evidence of beneficial change, showed how it occurred and has since been used as a basis for planning, documenting and assessing progress in rainforest regeneration. Reformation of the canopy allowed the forest floor to stabilize under a more constant microclimate, encouraging germination of shade-loving rainforest species. Maximum and minimum temperature values demonstrated the buffering effect of the closed rainforest canopy. After 20 years, Wingham Brush has changed from a degraded forest, dominated by exotic vines, with many large gaps in the canopy, to a rainforest with an intact canopy, enlarged core forest area and reduced edge effect, that supports the diversity and structure of a healthy subtropical rainforest. Techniques developed in the ‘Wingham Brush Method’, have become the basis for restoration programs in other rainforest areas. The principles are: be canopy-focused, be flexible, assess each site individually, and use techniques appropriate to problems encountered and goals of the long-term program.