Juvenile tree growth and demography in response to feral water buffalo in savannas of northern Australia: an experimental field study in Kakadu National Park

2006 ◽  
Vol 54 (3) ◽  
pp. 283 ◽  
Author(s):  
P. A. Werner ◽  
I. D. Cowie ◽  
J. S. Cusack
Keyword(s):  
Field Study ◽  
Tree Growth ◽  
National Park ◽  
Water Buffalo ◽  
Ground Level ◽  
Northern Australia ◽  
Growth And Survival ◽  
Major Mechanism ◽  
Scale Experiment ◽  
Juvenile Plants

Tree populations in the wooded savannas of northern Australia lack a well developed seed bank, but instead rely on a persistent ground layer of suppressed juvenile plants <1 m of indeterminate ages. The feral Asian water buffalo has been implicated as a factor in inhibiting the movement of juvenile trees to sapling stage. In a 6-year field study in Kakadu National Park, 656 juvenile plants were monitored for growth and survival, and in exploring the effects of buffalo, clipping surrounding vegetation and ambient fire. Buffalo were removed from one half of the sites across an environmental gradient in a landscape-scale experiment. Juvenile trees grew more slowly but fewer became dormant where buffalo were absent. Experimental clipping of surrounding vegetation produced significantly increased height at the buffalo-absent sites, but not at the buffalo-present sites, demonstrating that the positive effect of buffalo on growth was indirect, by reducing the competitive regime for juvenile trees. Within 3 years of removal of buffalo, ground-level green biomass increased 2–10 times and litter 1.3–2 times over a topographic gradient. Mortality of juvenile trees was not significantly different between buffalo-present and buffalo-absent sites when plots remained unburnt. By contrast, at buffalo-absent sites, three times more juveniles died after late dry-season fires than at unburnt sites, but there was no difference among buffalo-present sites. Overall, the total juvenile tree bank decreased by 7% where buffalo grazed and by 18% where buffalo had been removed. The study demonstrated a major mechanism(s) responsible for recorded changes in vegetation patterns of these savannas, whereby buffalo initiate a cascade of effects by changing ground-level biomass, which change competitive relationships and fuel loads, which then have an impact on tree growth and demography. The results are discussed with respect to dynamics of the juvenile tree bank and implications for long-term sustainability of these wooded savannas.

scholarly journals Marsh rabbit mortalities tie pythons to the precipitous decline of mammals in the Everglades

2015 ◽  
Vol 282 (1805) ◽  
pp. 20150120 ◽  
Author(s):  
Robert A. McCleery ◽  
Adia Sovie ◽  
Robert N. Reed ◽  
Mark W. Cunningham ◽  
Margaret E. Hunter ◽  
...  
Keyword(s):  
National Park ◽  
Large Scale ◽  
Ongoing Debate ◽  
Faunal Communities ◽  
Python Molurus ◽  
Scale Experiment ◽  
Precipitous Decline ◽  
Python Molurus Bivittatus ◽  
The Impact ◽  
Ecological Functioning

To address the ongoing debate over the impact of invasive species on native terrestrial wildlife, we conducted a large-scale experiment to test the hypothesis that invasive Burmese pythons ( Python molurus bivittatus ) were a cause of the precipitous decline of mammals in Everglades National Park (ENP). Evidence linking pythons to mammal declines has been indirect and there are reasons to question whether pythons, or any predator, could have caused the precipitous declines seen across a range of mammalian functional groups. Experimentally manipulating marsh rabbits, we found that pythons accounted for 77% of rabbit mortalities within 11 months of their translocation to ENP and that python predation appeared to preclude the persistence of rabbit populations in ENP. On control sites, outside of the park, no rabbits were killed by pythons and 71% of attributable marsh rabbit mortalities were classified as mammal predations. Burmese pythons pose a serious threat to the faunal communities and ecological functioning of the Greater Everglades Ecosystem, which will probably spread as python populations expand their range.

Using LiDAR Point Clouds in Determination of the Scots Pine Stands Spatial Structure Meaning in the Conservation of Lichen Communities in “Bory Tucholskie” National Park

2019 ◽  
Vol 31 (1) ◽  
pp. 85-103
Author(s):  
Piotr Wężyk ◽  
Paweł Hawryło ◽  
Marta Szostak ◽  
Karolina Zięba-Kulawik ◽  
Monika Winczek ◽  
...  
Keyword(s):  
Spatial Structure ◽  
National Park ◽  
Laser Scanning ◽  
Ground Level ◽  
Point Clouds ◽  
Organic Layer ◽  
Active Protection ◽  
Scanning Lidar ◽  
Pine Stands ◽  
Biometric Features

Abstract The aim of the research carried out in 2018 and financed by the Forest Fund was the analysis of biometric features and parameters of pine stands in the area of the “Bory Tucholskie” National Park (PNBT), where a program of active protection of lichen was initiated in 2017. Environmental analyses were conducted in relation to selected biometric features of trees and stands using laser scanning (LiDAR), including ULS (Unmanned Laser Scanning; RIEGL VUX-1) and TLS (Terrestrial Laser Scanning; FARO FOCUS 3D; X130). Thanks to the application of LiDAR technology, the structure of pine stands was precisely determined by means of a series of descriptive statistics characterizing the 3D spatial structure of vegetation. Using the Trees Crown Model (CHM), the analysis of the volume of tree crowns and the volume of space under canopy was performed. For the analysed sub-compartments, GIS solar analyses were carried out for the solar energy reaching the canopy and the ground level due to active protection of lichen. Multispectral photos were obtained using a specialized RedEdge-M camera (MicaSense) mounted on the UAV multi rotor platform Typhoon H520 (Yuneec). Flights with a thermal camera were also performed in order to detect places on the ground with high temperature. Plant indices: NDVI, NDRE, GNDVI and GRVI were also calculated for sub-compartments. The data obtained in 2017 and 2018 were the basis for spatial and temporal analyses of 4-D changes in stands which were related to the removal of some trees and organic layer (litter, moss layer).

scholarly journals Field study site selection, species abundance and monthly distribution of anopheline mosquitoes in the northern Kruger National Park, South Africa

2014 ◽  
Vol 13 (1) ◽  
pp. 27 ◽  
Author(s):  
Givemore Munhenga ◽  
Basil D Brooke ◽  
Belinda Spillings ◽  
Leyya Essop ◽  
Richard H Hunt ◽  
...  
Keyword(s):  
South Africa ◽  
Field Study ◽  
Site Selection ◽  
National Park ◽  
Species Abundance ◽  
Kruger National Park ◽  
Monthly Distribution ◽  
Anopheline Mosquitoes

Fire regimes and interval-sensitive vegetation in semiarid Gregory National Park, northern Australia

2010 ◽  
Vol 58 (4) ◽  
pp. 300 ◽  
Author(s):  
Jeremy Russell-Smith ◽  
Cameron P. Yates ◽  
Chris Brock ◽  
Vanessa C. Westcott
Keyword(s):  
National Park ◽  
Fire Regime ◽  
Woody Species ◽  
Fire Regimes ◽  
Stem Density ◽  
Northern Australia ◽  
Juvenile Period ◽  
Climate Conditions ◽  
Fine Fuels ◽  
Ecologically Sustainable

Few data are available concerning contemporary fire regimes and the responses of fire interval-sensitive vegetation types in semiarid woodland savanna landscapes of northern Australia. For a 10 300 km2 semiarid portion of Gregory National Park, in the present paper we describe (1) components of the contemporary fire regime for 1998–2008, on the basis of assessments derived from Landsat and MODIS imagery, (2) for the same period, the population dynamics, and characteristic fine-fuel loads associated with Acacia shirleyi Maiden (lancewood), an obligate seeder tree species occurring in dense monodominant stands, and (3) the fire responses of woody species, and fine-fuel dynamics, sampled in 41 plots comprising shrubby open-woodland over spinifex hummock grassland. While rain-year (July–June) rainfall was consistently reliable over the study period, annual fire extent fluctuated markedly, with an average of 29% being fire affected, mostly in the latter part of the year under relatively harsh fire-climate conditions. Collectively, such conditions facilitated short fire-return intervals, with 30% of the study area experiencing a repeat fire within 1 year, and 80% experiencing a repeat fire within 3 years. Fine fuels associated with the interior of lancewood thickets were characteristically small (<1 t ha–1). Fine fuels dominated by spinifex (Triodia spp.) were found to accumulate at rates equivalent to those observed under higher-rainfall conditions. Stand boundaries of A. shirleyi faired poorly under prevailing fire regimes over the study period; in 16 plots, juvenile density declined 62%, and adult stem density and basal area declined by 53% and 40%, respectively. Although the maturation (primary juvenile) period of A. shirleyi is incompletely known, assembled growth rate and phenology data indicated that it is typically >10 years. Of 133 woody species sampled, all trees (n = 26), with the exception of A. shirleyi, were resprouters, and 58% of all shrub species (n = 105) were obligate seeders, with observed primary juvenile periods <5 years. Assembled data generally supported observations made from other northern Australian studies concerning the responses of fire-sensitive woody taxa in rugged, sandstone-derived landscapes, and illustrated the enormous challenges facing ecologically sustainable fire management in such settings. Contemporary fire regimes of Gregory National Park are not ecologically sustainable.

scholarly journals Patterns of Diversity and Distribution of Arboreal Social Bees’ Beehives within Chimpanzees’ Home Range in a Forest-Savanna Mosaic (Comoé National Park, Côte d’Ivoire)

Sociobiology ◽  
2019 ◽  
Vol 66 (3) ◽  
pp. 480
Author(s):  
Angele Nicodenin Soro ◽  
Juan Lapuente ◽  
Abduoulaye Ngolo Kone ◽  
Kolo Yeo ◽  
Souleymane Konate
Keyword(s):  
National Park ◽  
Secondary Forest ◽  
Ground Level ◽  
Home Ranges ◽  
Gallery Forest ◽  
Habitat Types ◽  
Social Bees ◽  
Mature Forest ◽  
Forest Island ◽  
Forest Habitats

The goal of this study was to explain the patterns of diversity and distribution of arboreal social bees nesting in forest habitats of the Comoé National park, within the home-ranges of wild chimpanzees that consume their honey. Investigations were done using a total sixteen plots, one hectare each, established in three habitat types (mature forest island, secondary forest island and gallery forest). The diversity and distribution of arboreal social bees was estimated with visuals searches. The exploitation of the beehives of these bee by the chimpanzees was also evaluated using chimpanzees’ honey dipping tools as indicators. Results revealed five bees’ species belonging to two tribes; Meliponini (Meliponula ferruginea, Meliponula togoensis, Meliponula bocandei, Hypotrigona gribodoi) and Apini (Apis mellifera). Frequent exploitation of the honey of stingless bees by the chimpanzees was observed, except for H. gribodoi. Meliponula ferruginea was the most exploited species by chimpanzees. A total of 114 beehives were found in the overall established plots leading to an estimated density of 2.4 beehives/ha in the study area. Among the surveyed habitats, mature forest island was found to harbor the highest beehive density (4.2 beehives/ha), followed respectively by secondary-forest island (1.9 beehives/ha) and gallery forest (1.1 beehives/ha). Finally, all bee species were found nesting in cavities of trees with a DBH ranging from 15 to 87.3 cm, with a special preference for Dialium guinneense. However, the DBH of nesting trees and beehives’ height, measured from the ground level, did not significantly influence the honey exploitation by chimpanzees. In sum bee species diversity and distribution might be important in the survival of chimpanzees of a forest savanna landscape.

scholarly journals Spatial distribution of spruce trees in the nature reserve 'Jankove bare' on mt. Kopaonik

2009 ◽  
pp. 191-204
Author(s):  
Branko Stajic ◽  
Milivoj Vuckovic ◽  
Marko Smiljanic
Keyword(s):  
Spatial Distribution ◽  
Tree Growth ◽  
Environmental Conditions ◽  
National Park ◽  
Nature Reserve ◽  
Distance Methods ◽  
Study Results

The methodology and applicability of the study of spatial distribution of trees in Serbian forestry have been insufficiently reported and presented. This paper, based on mathematical?statistical principles, analyses the method of spatial distribution of spruce trees in the Nature Reserve 'Jankove Bare' in the National Park 'Kopaonik'. The following methods in the group of distance methods were applied: Kotar's method (1993), T2?method, and the index of distance dispersion (Johnson, Zimmer, 1985). The study results in a pure uneven-aged spruce stand based on all three methods showed that spruce trees are randomly distributed over the stand area. Therefore, environmental conditions in the study stand can be regarded as homogeneous and equally suitable for tree growth, and there are no significant interactions between the trees, which could cause a higher competition between the trees for nutrients, water, etc.

scholarly journals Spatial Dynamics of Invasive Para Grass on a Monsoonal Floodplain, Kakadu National Park, Northern Australia

2019 ◽  
Vol 11 (18) ◽  
pp. 2090
Author(s):  
Boyden ◽  
Wurm ◽  
Joyce ◽  
Boggs
Keyword(s):  
Satellite Imagery ◽  
Wild Rice ◽  
National Park ◽  
Fire History ◽  
Spatial Dynamics ◽  
Gradient Boosting ◽  
Native Vegetation ◽  
Northern Australia ◽  
Stochastic Gradient Boosting ◽  
The World

African para grass (Urochloa mutica) is an invasive weed that has become prevalent across many important freshwater wetlands of the world. In northern Australia, including the World Heritage landscape of Kakadu National Park (KNP), its dense cover can displace ecologically, genetically and culturally significant species, such as the Australian native rice (Oryza spp.). In regions under management for biodiversity conservation para grass is often beyond eradication. However, its targeted control is also necessary to manage and preserve site-specific wetland values. This requires an understanding of para grass spread-patterns and its potential impacts on valuable native vegetation. We apply a multi-scale approach to examine the spatial dynamics and impact of para grass cover across a 181 km2 floodplain of KNP. First, we measure the overall displacement of different native vegetation communities across the floodplain from 1986 to 2006. Using high spatial resolution satellite imagery in conjunction with historical aerial-photo mapping, we then measure finer-scale, inter-annual, changes between successive dry seasons from 1990 to 2010 (for a 48 km2 focus area); Para grass presence-absence maps from satellite imagery (2002 to 2010) were produced with an object-based machine-learning approach (stochastic gradient boosting). Changes, over time, in mapped para grass areas were then related to maps of depth-habitat and inter-annual fire histories. Para grass invasion and establishment patterns varied greatly in time and space. Wild rice communities were the most frequently invaded, but the establishment and persistence of para grass fluctuated greatly between years, even within previously invaded communities. However, these different patterns were also shown to vary with different depth-habitat and recent fire history. These dynamics have not been previously documented and this understanding presents opportunities for intensive para grass management in areas of high conservation value, such as those occupied by wild rice.

scholarly journals Small mammals from Miri, northeastern region of Sarawak, Malaysian Borneo: note on new locality records

Check List ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. 1863 ◽  
Author(s):  
Nursyafiqah Shazali ◽  
Sultana Parvin Habeebur Rahman ◽  
Nurul Farah Diyana Ahmad Tahir ◽  
Rafik Murni ◽  
Nurshilawati Abdul Latip ◽  
...  
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
National Park ◽  
Ground Level ◽  
Northeastern Region ◽  
First Time ◽  
Mammal Diversity ◽  
Malaysian Borneo

Small mammal surveys were conducted at Niah National Park, Lambir Hills National Park and Gunung Mulu National Park, Miri Division, in the northeastern region of Sarawak, using ground-level and canopy mist-nets, harp traps, and cage traps. The main objective of these surveys was to assess small mammal diversity in the northeastern region of Sarawak. Gunung Mulu National Park recorded the highest diversity of small mammals with 29 species, followed by Niah National Park with 19 species, and Lambir Hills National Park, 17 species. These surveys revealed nine new locality records for Miri, including eight bat species (Dyacopterus spadiceus, Megaerops wetmorei, Nycteris tragata, Hipposideros cineraceus, Hesperoptenus blanfordi, Kerivoula pellucida, Murina suilla and Myotis muricola)and a squirrel (Sundasciurus brookei). Megaerops wetmorei is also reported for the first time in Sarawak.

Sign in / Sign up

Export Citation Format

Share Document