Salt-wind induced wave regeneration in coastal pine forests in New Zealand

1998 ◽  
Vol 28 (7) ◽  
pp. 953-960 ◽  
Author(s):  
D J Campbell
Keyword(s):  
New Zealand ◽  
Clear Cut ◽  
Litter Depth ◽  
Age Related ◽  
Pine Seedlings ◽  
Closed Canopy ◽  
Wave Regeneration ◽  
Mature Stands ◽  
Stocking Rates ◽  
Summer Dryness

Strong onshore winds and airborne sea salt can gradually defoliate trees at the exposed margin of temperate pine stands in New Zealand and induce a slowly moving front of dieback and regeneration. Overcrowded mature stands are vulnerable to crown abrasion: abrasion affects trees 20 m ahead of the dieback front; suppressed trees 12 m ahead die before the front reaches them. At the stand margin, trees die from abrasion and salt wind induced dieback. The dieback zone lets sunlight enter the stand; light-demanding pine seedlings establish, but a gradient of increasing litter depth from the dieback front and summer dryness restrict successful seedling establishment to a narrow zone that moves parallel with the dieback front and 11-13 m ahead of it. Further seedlings establish for 4-10 years before the juveniles form a closed canopy; competing vegetation is partly suppressed by infrequent cattle browsing. Regenerating juvenile maritime pine (Pinus pinaster Ait.), show a strict age-related gradation from the dieback front and indicate that wind and salt deposition have been constant for 30 years. Stands further from the sea, with lower stocking rates and other pine species, did not have a clear-cut regeneration zone, because there were no strong gradients of litter depth and light intensity.

Methane emissions from young and mature dairy cattle

2016 ◽  
Vol 56 (11) ◽  
pp. 1897 ◽  
Author(s):  
C. A. Ramírez-Restrepo ◽  
H. Clark ◽  
S. Muetzel
Keyword(s):  
New Zealand ◽  
Emission Factor ◽  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Dry Matter Intake ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Age Related ◽  
The Mean

Daily methane (CH4) emissions (g) and CH4 yield (g/kg dry matter intake) were measured from 10 dairy heifers (<1 year old) and nine rumen-fistulated cows (>6 years old) fed ryegrass (Lolium perenne) chaffage indoors. The CH4 emissions were estimated using the sulfur hexafluoride tracer technique in four ~5-day periods beginning in June 2008 and repeated 4, 6 and 7 months later. Respiratory chambers were used in four ~13-day periods beginning in November 2008 and repeated 2, 5 and 6 months later. Third and fourth sulfur hexafluoride tracer periods overlapped with the first and second chamber measurement periods, respectively. Averaged over the four measurement periods the CH4 yields determined using both techniques were similar for heifers and cows. The mean CH4 yield estimated by the sulfur hexafluoride tracer technique was 25.3 ± 0.52 for heifers and 24.1 ± 0.55 for mature cows, whereas the mean CH4 yield measured in respiratory chambers was 23.7 ± 0.66 for heifers and 23.6 ± 0.66 for mature cows. Averaged over the eight measurements irrespective of technique, CH4 yields for heifers (24.5 ± 0.42) and cows (23.8 ± 0.43) were similar. There was also no difference between CH4 methods for assessing CH4 yield during the overlapping measurement periods. It was concluded that no consistent differences in CH4 yield existed between heifers and mature cows. Therefore, we do not recommend adoption of an age-related emission factor for cattle in the national inventory calculations for New Zealand.

Nitrogen storage and availability during stand development in a New Zealand Nothofagus forest

2002 ◽  
Vol 32 (2) ◽  
pp. 344-352 ◽  
Author(s):  
P W Clinton ◽  
R B Allen ◽  
M R Davis
Keyword(s):  
New Zealand ◽  
Forest Floor ◽  
Woody Debris ◽  
Mineral Soil ◽  
Stand Development ◽  
N Availability ◽  
Net N Mineralization ◽  
Nitrogen Storage ◽  
Nothofagus Forest ◽  
Mature Stands

Stemwood production, N pools, and N availability were determined in even-aged (10, 25, 120, and >150-year-old) stands of a monospecific mountain beech (Nothofagus solandri var. cliffortioides (Hook. f.) Poole) forest in New Zealand recovering from catastrophic canopy disturbance brought about by windthrow. Nitrogen was redistributed among stemwood biomass, coarse woody debris (CWD), the forest floor, and mineral soil following disturbance. The quantity of N in stemwood biomass increased from less than 1 kg/ha in seedling stands (10 years old) to ca. 500 kg/ha in pole stands (120 years old), but decreased in mature stands (>150 years old). In contrast, the quantity of N stored in CWD declined rapidly with stand development. Although the mass of N stored in the forest floor was greatest in the pole stands and least in the mature stands, N availability in the forest floor did not vary greatly with stand development. The mass of N in the mineral soil (0–100 mm depth) was also similar for all stands. Foliar N concentrations, net N mineralization, and mineralizable N in the mineral soil (0–100 mm depth) showed similar patterns with stage of stand development, and indicated that N availability was greater in sapling (25 years old) and mature stands than in seedling and pole stands. We conclude that declining productivity in older stands is associated more with reductions in cation availability, especially calcium, than N availability.

scholarly journals Electrophysiological Evidence for Preserved Primacy of Lexical Prediction in Normative Aging

2017 ◽  
Author(s):  
Shruti Dave ◽  
Trevor A. Brothers ◽  
Matthew J. Traxler ◽  
Fernanda Ferreira ◽  
John M. Henderson ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Prediction Accuracy ◽  
Predictive Accuracy ◽  
Accurate Prediction ◽  
Self Report ◽  
Clear Cut ◽  
Age Related ◽  
Contextual Support ◽  
Normative Aging

Young adults show consistent neural benefits of predictable contexts when processing upcoming words, but these benefits are less clear-cut in older adults. Here we conduct two ERP experiments to examine whether aging uniquely affects neural correlates of prediction accuracy, as compared to contextual support independent of accuracy. In Experiment 1, readers were asked to predict sentence-final words and self-report prediction accuracy, allowing for separation of ERP effects of accurate prediction and contextual support. While N250 and N400 effects of accurate prediction were reduced in older readers, both temporal primacy and relative amplitudes of predictive compared to contextual processing were similar across age. In Experiment 2, participants read for comprehension without an overt prediction task and showed similar age-related declines in N400 amplitude across experiments. In both studies, older adults showed relatively larger frontal post-N400 positivities (PNPs) than young adults, suggesting age-graded differences in revision following unexpected items. Previous research suggests the production system may be linked to lexical prediction, but here we found that verbal fluency modulated PNP effects of contextual support, but not predictive accuracy. Taken together, our findings suggest that normative aging does not result in specific declines or boosts of lexical prediction.

scholarly journals Key Roles for Landscape Ecology in Transformative Agriculture Using Aotearoa—New Zealand as a Case Example

Land ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 146
Author(s):  
Diane Pearson
Keyword(s):  
New Zealand ◽  
Landscape Ecology ◽  
Farming Systems ◽  
Alternative Futures ◽  
Related Information ◽  
Aotearoa New Zealand ◽  
Link Theory ◽  
Scientific Context ◽  
Farming Landscapes ◽  
Stocking Rates

Aotearoa—New Zealand (NZ) is internationally renowned for picturesque landscapes and agricultural products. Agricultural intensification has been economically beneficial to NZ but has implications for its clean green image. Contaminated waterways, high carbon emissions, and extensive soil erosion demonstrate the downside of high stocking rates and land clearing. Transformative farming systems are required to address the challenge of balancing production with the environment. Whilst navigating through the process of change, farmers need to be supported to make informed decisions at the farm and landscape scale. Landscape ecology (LE) is ideally positioned to inform the development of future farming landscapes and provide a scientific context to the criteria against which land-related information can be evaluated. However, to do this effectively, LE needs to demonstrate that it can link theory with practice. Using NZ as a case example, this paper discusses the key roles for LE in future farming systems. It looks at the way LE can help quantify the state of the landscape, provide support towards the co-creation of alternative futures, and assist with the inclusion of land-related information into design and planning to ensure mitigation and adaption responses assist in the transformation of farming systems for sustainable outcomes.

scholarly journals Past and Present Vulnerability of Closed-Canopy Temperate Forests to Altered Fire Regimes: A Comparison of the Pacific Northwest, New Zealand, and Patagonia

BioScience ◽  
2014 ◽  
Vol 65 (2) ◽  
pp. 151-163 ◽  
Author(s):  
Cathy Whitlock ◽  
David B. McWethy ◽  
Alan J. Tepley ◽  
Thomas T. Veblen ◽  
Andrés Holz ◽  
...  
Keyword(s):  
New Zealand ◽  
Pacific Northwest ◽  
Temperate Forests ◽  
Fire Regimes ◽  
The Pacific ◽  
Closed Canopy

Genetics of wood stiffness and its component traits inPinus radiata

2006 ◽  
Vol 36 (5) ◽  
pp. 1165-1178 ◽  
Author(s):  
Heidi S Dungey ◽  
A Colin Matheson ◽  
Dominic Kain ◽  
Robert Evans
Keyword(s):  
New Zealand ◽  
Genetic Correlations ◽  
Microfibril Angle ◽  
Early Selection ◽  
Stiffness Modulus ◽  
Wood Stiffness ◽  
South Wales ◽  
Age Related ◽  
Component Traits ◽  
Selection For

The potential for breeding Pinus radiata D. Don to improve wood stiffness (modulus of elasticity, MoE) was examined by obtaining pith-to-bark cores from trees at breast height in two independent genetic trials. The effectiveness of early selection for stiffness and indirect selection on the component traits, microfibril angle (MfA) and wood density, was determined as well as the age-related changes in the genetic variation of these traits. The first trial comprised 50 open-pollinated families in the central North Island, New Zealand. The second trial comprised 20 control-pollinated families in New South Wales, Australia. The genetic control of MfA, density, and MoE was found to be high in the corewood and moderate in the outerwood. Estimated genetic correlations suggested that early selection for most traits would be successful but could be carried out slightly earlier at the New Zealand site than at the Australian site. To maximize gain in the corewood, selection for MoE and MfA would be most effective around rings 4-8. There were no adverse correlations between MoE and MfA or density, implying that selection for MoE would also improve MfA and density.

scholarly journals A paleolimnological investigation of agricultural intensification, water quality and ecosystem change at Lake Nganoke, southern Wairarapa, NZ

2021 ◽  
Author(s):  
◽  
Jakob Parrish
Keyword(s):  
Water Quality ◽  
New Zealand ◽  
Agricultural Intensification ◽  
Ecosystem Change ◽  
Lake Ecosystem ◽  
Nutrient Fluxes ◽  
Paleoenvironmental Reconstruction ◽  
The Past ◽  
Algal Productivity ◽  
Stocking Rates

<p>Decreasing water quality of lakes as a result of anthropogenic landuse and specifically agricultural intensification is well documented in New Zealand. However, monitoring records of lake health are typically short, only commencing once signs of lake deterioration are observed. The shortness of the instrumental record precludes a detailed understanding of the relationship between landuse change, lake ecosystem trajectories and the effectiveness of mitigation strategies such as riparian planting. Paleolimnological reconstruction from sediment cores has the potential to develop high-resolution time series that may extend lake monitoring centuries into the past. This thesis uses paleoenvironmental reconstruction to investigate lake ecosystem change and water quality in Lake Nganoke, Wairarapa, New Zealand as a result of landuse intensification. The primary aim of this thesis is to reconstruct the past environment of Lake Nganoke from a pre-human reference state to the current day to assess: 1) how increased nutrient fluxes associated with landuse intensification have impacted the lake ecosystem; and 2) the ability of riparian zones to buffer these fluxes. The reconstruction was achieved using a multi proxy approach with pre and post-human environments of Lake Nganoke characterised using Palynology, geochemistry, eDNA and hyperspectral scanning.  Māori land clearance was identified at ~AD 1450 (95% CI: AD 1417-1551). The appearance of Pinus pollen and increases in fertilisation and stocking rates placed European arrival at ~AD 1850 (95% CI: 1809 - 1870), while intensification of agricultural landuse occurred post ~AD 1950 (95% CI: 1948 - 1964). The prehuman environment of Lake Nganoke experienced little change, with the catchment dominated by tall trees and likely heavily forested. The lake ecosystem and water quality during this time showed little to no change, with algal productivity likely driven by a constant input of natural nutrients. Post Māori arrival, algal productivity was reduced suggesting an increase in water quality likely driven by added lake marginal plants providing a riparian buffer to terrestrially derived nutrients. Lake productivity increased dramatically post European arrival ~AD 1850, coeval with an increase in sediment Cd, suggesting that fertilisation may have driven a decline in water quality. Further increases in fertilisation and stocking rates indicate additional agricultural nutrient fluxes entering Lake Nganoke in AD 1950 when agriculture intensified. Abundances in denitrifying Gammaproteobacteria indicate increases in nutrient loading while bloom forming Cyanobacteria peak ~AD 2000 before declining till present. Riparian planting following Māori arrival appears sufficient to buffer the lake against increased terrestrial nutrient fluxes associated with land clearing. However, a riparian zone that covers the majority of the catchment post European settlement was inadequate in altering the lake’s degrading ecosystem and water quality trajectory.</p>

scholarly journals Insect visitors to avocado flowers in the Bay of Plenty, New Zealand

2017 ◽  
Vol 70 ◽  
pp. 38-44 ◽  
Author(s):  
S.F.J. Read ◽  
B.G. Howlett ◽  
L.K. Jesson ◽  
D.E. Pattemore
Keyword(s):  
New Zealand ◽  
Honey Bee ◽  
Honey Bees ◽  
Insect Species ◽  
Insect Pollination ◽  
Flower Visitor ◽  
Production Area ◽  
Abundance And Diversity ◽  
Stocking Rates ◽  
Insect Visitors

Insect pollination is key to ensuring adequate fruit yields within avocado orchards. Various bee and non-bee insect species have been considered as potential pollinators of avocado worldwide, but in New Zealand there has been little research into which insect species visit avocado flowers. In the Bay of Plenty, an important avocado production area, flower visitor abundance and diversity data were obtained by conducting observational surveys in four orchards in November 2015. Honey bees were the dominant flower visitors in all orchards surveyed, representing 92.9% of all insects recorded, but there was high variation in numbers among sites. Other common insects observed included the beetle, Zorion guttigerum (3.4%), and bumblebees Bombus spp. (1.6%). A better understanding of the interaction between honey bee stocking rates and flower visitor abundances within orchards could assist in improving pollination recommendations.

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