Regeneration in indigenous forest after eradication of Norway rats, Breaksea Island, New Zealand

1994 ◽  
Vol 32 (4) ◽  
pp. 429-439 ◽  
Author(s):  
R. B. Allen ◽  
W. G. Lee ◽  
B. D. Rance
2006 ◽  
Vol 33 (7) ◽  
pp. 613 ◽  
Author(s):  
Francis M. Kelliher ◽  
Harry Clark ◽  
Zheng Li ◽  
Paul C. D. Newton ◽  
Anthony J. Parsons ◽  
...  

Keppler et al. (2006, Nature 439, 187–191) showed that plants produce methane (CH4) in aerobic environments, leading Lowe (2006, Nature 439, 148–149) to postulate that in countries such as New Zealand, where grazed pastures have replaced forests, the forests could have produced as much CH4 as the ruminants currently grazing these areas. Estimating CH4 emissions from up to 85 million ruminants in New Zealand is challenging and, for completeness, the capacity of forest and pastoral soils to oxidise CH4 should be included. On average, the CH4 emission rate of grazing ruminants is estimated to be 9.6 ± 2.6 g m–2 year–1 (±standard deviation), six times the corresponding estimate for an indigenous forest canopy (1.6 ± 1.1 g m–2 year–1). The forest’s soil is estimated to oxidise 0.9 ± 0.2 g m–2 year–1 more CH4 than representative soils beneath grazed pasture. Taking into account plant and animal sources and the soil’s oxidative capacity, the net CH4 emission rates of forest and grazed ecosystems are 0.6 ± 1.1 and 9.8 ± 2.6 g m–2 year–1, respectively.


Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 702 ◽  
Author(s):  
Jan Zörner ◽  
John Dymond ◽  
James Shepherd ◽  
Susan Wiser ◽  
Ben Jolly

Indigenous forests cover 23.9% of New Zealand’s land area and provide highly valued ecosystem services, including climate regulation, habitat for native biota, regulation of soil erosion and recreation. Despite their importance, information on the number of tall trees and the tree height distribution across different forest classes is scarce. We present the first region-wide spatial inventory of tall trees (>30 m) based on airborne LiDAR (Light Detection and Ranging) measurements in New Zealand—covering the Greater Wellington region. This region has 159,000 ha of indigenous forest, primarily on steep mountainous land. We implement a high-performance tree mapping algorithm that uses local maxima in a canopy height model (CHM) as initial tree locations and accurately identifies the tree top positions by combining a raster-based tree crown delineation approach with information from the digital surface and terrain models. Our algorithm includes a check and correction for over-estimated heights of trees on very steep terrain such as on cliff edges. The number of tall trees (>30 m) occurring in indigenous forest in the Wellington Region is estimated to be 286,041 (±1%) and the number of giant trees (>40 m tall) is estimated to be 7340 (±1%). Stereo-analysis of aerial photographs was used to determine the accuracy of the automated tree mapping. The giant trees are mainly in the beech-broadleaved-podocarp and broadleaved-podocarp forests, with density being 0.04 and 0.12 (trees per hectare) respectively. The inventory of tall trees in the Wellington Region established here improves the characterization of indigenous forests for management and provides a useful baseline for long-term monitoring of forest conditions. Our tree top detection scheme provides a simple and fast method to accurately map overstory trees in flat as well as mountainous areas and can be directly applied to improve existing and build new tree inventories in regions where LiDAR data is available.


2013 ◽  
Vol 43 (3) ◽  
pp. 141-153 ◽  
Author(s):  
JR Dymond ◽  
A-GE Ausseil ◽  
MUF Kirschbaum ◽  
FE Carswell ◽  
NWH Mason

2006 ◽  
Vol 33 (7) ◽  
pp. 539 ◽  
Author(s):  
Grant Harper ◽  
Dick Veitch

Norway rats (Rattus norvegicus) are sympatric with, and more often trapped, than the smaller Pacific rat (R. exulans) on Raoul Island, New Zealand. Rats were removed from a four-hectare grid by trapping and poisoning in the winters of 1994, 1995 and 1996. Pacific rats were trapped in increasing numbers only after Norway rats were removed. Norway rats also ate significantly more bait than Pacific rats. Competitive interference of Pacific rats by Norway rats was apparent, which casts doubt on the ability to accurately monitor individual species abundance within assemblages of rat species and to effectively manage them in control grids. Snap-trapping lines provided baseline data on the abundance of the two species before, during and after the removal grids were operated. Maximum abundances of rats were recorded in late summer and autumn following spring and summer breeding.


2021 ◽  
Author(s):  
Andrew James Veale ◽  
Carolyn King ◽  
Wayne Johnson ◽  
Lara Shepherd

Abstract The present genetic diversity of commensal rodent populations is often used to inform the invasion histories of these species, and as a proxy for historical events relating to the movement of people and goods. These studies assume that modern genetic diversity generally reflects early colonising events. We investigate this idea by sequencing the mitochondrial DNA of rodent bones found in a 19th-century archaeological site in The Rocks area of Sydney, Australia, the location of the first historical European port. We identified 19th-century bones from two species, Rattus norvegicus and Mus musculus domesticus. We found six genetic haplotypes in the 39 Norway rats, showing either multiple early introductions or a diverse initial founding population. One of them was identical with Norhap01 common in the North Island of New Zealand, but none was like the haplotype Norhap02 found throughout the South Island. We found three haplotypes in seven house mice, all belonging to the dominant subspecies established in Australia, M.m. domesticus. There was no evidence for M. m. castaneus or M. m. musculus having established there. We had few modern R. norvegicus and M. musculus DNA sequences from Sydney, but those we had did tentatively support the hypotheses that (1) modern samples can represent at least a preliminary estimate of historical diversities and origins, and (2) Asian haplotypes of both Norway rats and of house mice reached the South Island of New Zealand early in colonial times direct from China rather than through Port Jackson.


1990 ◽  
Vol 17 (5) ◽  
pp. 541 ◽  
Author(s):  
B Warburton

Trials were carried out against Bennett's wallabies (Macropus rufogriseus rufogriseus) and tammar wallabies (M. eugenii) in areas of indigenous forest where browsing is preventing or damaging regeneration. Compound 1080 (sodium monofluoroacetate) in a carbopol gel was spread on the foliage of palatable plants. Numbers of Bennett's wallabies were reduced by 91% and tammar wallabies by 87%. These kill estimates compare favourably with those achieved using aerially sown baits. The costs per hectare of gel poisoning were estimated to be as little as 40% of those for aerial baiting, but the costs of using gel will increase as the control areas become larger, more rugged, and less easily traversed on foot.


Zootaxa ◽  
2010 ◽  
Vol 2387 (1) ◽  
pp. 28 ◽  
Author(s):  
MATHIAS JASCHHOF ◽  
CATRIN JASCHHOF

Manota spp. are quite common in all kinds of indigenous forest in New Zealand. Five species are present: M. maorica Edwards, M. granvillensis sp. n., M. birgitae sp. n., M. purakaunui sp. n., and M. regineae sp. n. They can be distinguished from one another by male genitalic characters, in particular those of gonostylus. New Zealand Manota form a monophyletic group though their relationship to Manota spp. outside New Zealand is unclear.


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