Impact of an exotic vine Clematis vitalba (F. Ranunculaceae) and of control measures on plant biodiversity in indigenous forest, Taihape, New Zealand

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.

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The key roles of seed banks in plant biodiversity management in New Zealand

NZGA: Research and Practice Series ◽

10.33584/rps.14.2008.3184 ◽

2010 ◽

Vol 14 ◽

pp. 5-11

Author(s):

W.M. Williams

Keyword(s):

New Zealand ◽

Introduced Species ◽

Intrinsic Value ◽

Seed Banks ◽

Indigenous Species ◽

Plant Biodiversity ◽

Biodiversity Management ◽

Recent Initiative ◽

New Zealand Flora ◽

Pasture Plants

The New Zealand flora is a mixture of indigenous and introduced species. The indigenous species have a high intrinsic value while the introduced species include all of the crop and pasture plants upon which the export-led economy depends. New Zealand must maintain both of these important sources of biodiversity in balance. Seed banks are useful tools for biodiversity management. In New Zealand, a seed bank for indigenous species has been a very recent initiative. By contrast, seed banks for introduced species have been established for over 70 years. The reasons for this discrepancy are discussed. For the economic species, conserved genetic diversity is used to enhance productivity and the environment. Large advances can be gained from species that are not used as economic plants. The gene-pool of white clover has been expanded by the use of minor species conserved as seeds in the Margot Forde Germplasm Centre. Keywords: Seed banks, biodiversity conservation, New Zealand flora

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LiDAR-Based Regional Inventory of Tall Trees—Wellington, New Zealand

Forests ◽

10.3390/f9110702 ◽

2018 ◽

Vol 9 (11) ◽

pp. 702 ◽

Cited By ~ 3

Author(s):

Jan Zörner ◽

John Dymond ◽

James Shepherd ◽

Susan Wiser ◽

Ben Jolly

Keyword(s):

New Zealand ◽

High Performance ◽

Tree Height ◽

Airborne Lidar ◽

Aerial Photographs ◽

Fast Method ◽

Height Distribution ◽

Detection Scheme ◽

Crown Delineation ◽

Indigenous Forest

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.

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Policies and management of overabundant deer (native or exotic) in protected areas

Animal Production Science ◽

10.1071/an10288 ◽

2011 ◽

Vol 51 (4) ◽

pp. 384 ◽

Cited By ~ 26

Author(s):

G. Nugent ◽

W. J. McShea ◽

J. Parkes ◽

S. Woodley ◽

J. Waithaka ◽

...

Keyword(s):

New Zealand ◽

North America ◽

Protected Areas ◽

Case Studies ◽

Control Measures ◽

South American ◽

Methodological Approaches

A workshop was convened in Chile in August 2010 as part of the 7th International Deer Biology Congress (IDBC). Its aim was to explore global differences in the policies and management of overabundant deer in protected areas. The main goal of the workshop was to provide South American researchers and managers with a snapshot of some of the approaches to management of deer overabundance used in a diverse array of case studies from North America, Europe, Australia and New Zealand. Various case studies were presented to illustrate the different methodological approaches in implementing deer control measures. Some general recommendations were formulated.

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Belled collars reduce catch of domestic cats in New Zealand by half

Wildlife Research ◽

10.1071/wr09127 ◽

2010 ◽

Vol 37 (5) ◽

pp. 372 ◽

Cited By ~ 33

Author(s):

J. K. Gordon ◽

C. Matthaei ◽

Y. van Heezik

Keyword(s):

New Zealand ◽

Urban Areas ◽

Experimental Studies ◽

Urban Wildlife ◽

Control Measures ◽

Domestic Cats ◽

The Public ◽

Negative Impacts ◽

Catch Rates ◽

The Uk

Context. As evidence accumulates implicating domestic cats as significant predators of urban wildlife, the need for effective mitigation of potentially negative impacts becomes more pressing. Belled collars are probably one of the cheapest and least intrusive methods, although the opinion of a proportion of members of the public in New Zealand is that they are not effective. Aims. We aimed to determine whether belled collars reduced prey catch. Methods. Prey caught and brought back home by cats that were regular hunters during 6 weeks when they wore a belled collar was compared with prey caught during 6 weeks when they did not wear a collar. Key results. Predation of birds and rodents was reduced by 50% and 61%, respectively. The number of rats, lizards and insects was not significantly reduced; however, these constituted a small proportion of the total catch. Sex and age of cats, as well as time did not affect catch rates, with the exception that older cats were more likely to catch rats (Rattus spp.) than were younger cats. Most of the cats in the study were young, reflecting our selection criteria that cats be regular and frequent hunters. Conclusions. The degree to which catch of birds and rodents was reduced is similar to that reported in two experimental studies in the UK, and confirms that belled collars are effective in the New Zealand environment. Implications. In New Zealand, small mammals are introduced pests and hunters of native wildlife; predation by cats may regulate their populations in urban areas and so care should be taken when instituting cat-control measures. It is also possible that a 50% reduction in predation may be insufficient to ensure viability for some urban wildlife populations.

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Opportunities for restoring indigenous forest in New Zealand

Journal of the Royal Society of New Zealand ◽

10.1080/03036758.2012.736393 ◽

2013 ◽

Vol 43 (3) ◽

pp. 141-153 ◽

Cited By ~ 2

Author(s):

JR Dymond ◽

A-GE Ausseil ◽

MUF Kirschbaum ◽

FE Carswell ◽

NWH Mason

Keyword(s):

New Zealand ◽

Indigenous Forest

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Population dynamics in echinococcosis and cysticercosis: mathematical model of the life-cycles of Taenia hydatigena and T. ovis

Parasitology ◽

10.1017/s0031182000053555 ◽

1987 ◽

Vol 94 (1) ◽

pp. 181-197 ◽

Cited By ~ 49

Author(s):

M. G. Roberts ◽

J. R. Lawson ◽

M. A. Gemmell

Keyword(s):

Population Dynamics ◽

Life Cycle ◽

New Zealand ◽

Equation Model ◽

Life Cycles ◽

Control Measures ◽

Taenia Hydatigena ◽

Infection Pressure ◽

Lower Infection ◽

Compare And Contrast

SUMMARYIt is shown that under the conditions that prevailed in New Zealand in the late 1950s, Taenia hydatigena was hyperendemic, the life-cycle being regulated by a density-dependent constraint in the form of acquired immunity, and T. ovis was rare. The control measures that caused Echinococcus granulosus, which was endemic at the time, to decline towards extinction reduced T. hydatigena and T. ovis to endemic status only. A non-linear integrodifferential equation model, which was previously linearized to describe the life-cycle of E. granulosus in dogs and sheep in New Zealand, is used to describe the life-cycles of T. hydatigena and T. ovis. The model is then used to compare and contrast the population dynamics of these three species. The model is used to demonstrate that the endemic steady state is structurally unstable, and may be asymptotically unstable to small perturbations. It is also shown that despite the lower infection pressure experienced by the intermediate host in the endemic state, the numbers of larvae in sheep may be higher than in the hyperendemic state. Finally it is shown that the partial success of the control measures against T. hydatigena may have caused an increase in the numbers and prevalence of T. ovis larvae in sheep due to the reciprocal immunity between the two species.

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