Search

New Zealand has implemented its Land Use and Carbon Analysis System (LUCAS) to meet its reporting commitments to the United Nations Framework Convention on Climate Change (UNFCCC) on carbon stock changes related to forests. A double sample design using airborne Light Detection and Ranging (LiDAR) and ground plots has been used for its recent national inventory of carbon stocks in planted forests that were established prior to 1990, using the experience gained with LiDAR from an earlier inventory of the post-1989 planted forests. For the pre-1990 inventory, ground-based, 0.06 hectare circular permanent sample plots were installed on an 8 × 8 km grid, with LiDAR flown in North–South transects across only those forests that contain a ground plot. LiDAR metrics were extracted for up to four 0.06 ha circular cells spaced at 1 km intervals either side of the ground plot and another cell over the ground location. Effectively, LiDAR data were collected on an incomplete 8 × 1 km grid, where individual forests have an unequal probability of being included in the sample. This paper describes the inventory design, those features of the plot measurement protocols that differ from the earlier inventory and the methods to calculate means and variances. Carbon stocks in each of the above- and below-ground live biomass, dead wood and litter pools were calculated for each ground plot at the time of measurement and predicted into the past and future using the Forest Carbon Predictor system. Field measurements of woody debris and litter are laborious and error prone when there has been a silvicultural operation and decay of residues. Given standing tree measurements and a description of past silviculture, the carbon stocks in the woody debris and litter pools are most efficiently estimated by the system rather than measured directly. The LiDAR data were used with regression estimators that explained 80% of the variance in total carbon, where the height percentile P40ht was the best variable. The combination of 686 LiDAR-only plots with a further 191 LiDAR/ground measured plots reduced the confidence interval to 11.1% of the mean total carbon stock per hectare from 14.1% using ground plots only. It had the advantage of being easier and faster to implement than an inventory with the increased number of ground plots required for an equivalent level of precision. A standard double sampling procedure with LiDAR plots on the complete 8 × 1 km grid would have required lengthy flying and been too costly.

To meet Kyoto Protocol obligations, New Zealand is required to estimate forest carbon stock change over the first commitment period (2008–2012). New Zealand has three subcategories of forest, namely: Natural forest; Pre-1990 forest; and Post-1989 forest. The Post-1989 forest carbon inventory undertaken in 2008 used discrete return airborne LiDAR and ground-based measurements of 0.06 ha circular plots located on a 4-km × 4-km grid. The national carbon stock estimate was based on a double sampling scheme consisting of 246 plots from which both ground and LiDAR data were obtained, supplemented with 46 additional plots assessed using only LiDAR. This paper describes the relationships established between carbon stocks estimated using ground-based measurements and LiDAR metrics. A regression model explaining 74% of the variation in total carbon was developed using LiDAR 30th percentile height (P30ht) and canopy cover (%Cover). The regression estimator improved the precision of the national carbon stock estimate in 2008 by 6% compared to the ground-based estimate. This inventory indicates that it is possible to reduce the cost of obtaining carbon stock estimates to a specified level of precision using a combination of ground-based and LiDAR measurements in a double sampling approach. The theoretical maximum improvement in precision expected in 2012, when additional LiDAR data are expected to be available, is 50–55%.

The United Nations Framework Convention on Climate Change (UNFCCC) requires reporting net carbon stock changes and anthropogenic greenhouse gas emissions, including those related to forests. This paper describes the design and implementation of a nation-wide forest inventory of New Zealand’s planted post-1989 forests that arose from Land Use, Land-Use Change and Forestry activities (LULUCF) under Article 3.3 of the Kyoto Protocol. The majority of these forests are planted with Pinus radiata, with the remainder made up of other species exotic to New Zealand. At the start of the project there was no on-going national forest inventory that could be used as a basis for calculating carbon stocks and meet Good Practice Guidelines. A network of ground-based permanent sample plots was installed with airborne LiDAR (Light Detection and Ranging) for double sampling using regression estimators to predict carbon in each of the four carbon pools of above- and below-ground live biomass, dead wood and litter. Measurement, data acquisition and quality assurance/control protocols were developed specifically for the inventory, carried out in 2007 and 2008. Plots were located at the intersection of a forest with a 4 km square grid, coincident with an equivalent 8 km square grid established over the indigenous forest and “grassland with woody biomass” (Other Wooded Land). Planted tree carbon within a ground plot was calculated by an integrated system of growth, wood density and compartment allocation models utilising the data from measurements of trees and shrubs on the plots. This system, called the Forest Carbon Predictor, predicts past and future carbon in a stand and is conditioned so that the calculated basal area and mean top height equals that obtained by conventional mensuration methods at the time of the plot measurement. Mean per hectare carbon stocks were then multiplied by an estimate of the total area of post 1989 forests obtained from wall to wall mapping using a combination of satellite imagery and ortho-photography. The network of permanent samples plots and LiDAR double sampling methodology was designed to be simple and robust to change over time. In the future, using LiDAR should achieve sampling efficiencies over using ground plots alone and reduces any problems regarding restricted access on the ground. The network is to be remeasured at the end of commitment period 1, 2012, and the carbon stocks re-estimated in order to calculate change.

Decay rates of stems, branches and roots were assessed in Pinus radiata (D. Don) plantation forests located throughout New Zealand. Stem and branch decay rates were obtained using (1) post-harvest material from two central North Island locations (Kaingaroa and Tarawera Forests) based on a 10-year chronosequence (in ground contact or suspended) and (2) post-thinning stems and attached branch material from five sites covering a range of climatic conditions across New Zealand (Woodhill, Puruki, Hokonui, Nemona and Selwyn) with up to 5 years of decay. Stem, stump and root decay rates were determined from two central North Island locations (Kinleith and Puruki) from thinnings with 0, 5, and 10 years of decay (Kinleith) and mature trees at 0 and 11 years of decay (Puruki). Stem and branch post-harvest material decayed faster when in contact with the ground than when elevated above the ground. The proportion of material elevated or in ground contact was not estimated in this study. P. radiata discs from young trees and post-harvest residue showed no significant diameter effect on decay rate and could be used confidently to predict whole stem decay rate. Discs from older trees covering a larger diameter range at Puruki showed a significant effect of diameter on decay rate. Decay rates of coarse roots at the two central North Island sites were faster than above-ground whole stem decay rates. Exponential models incorporating mean annual temperature for P. radiata stems in ground contact arising from thinning and harvest currently provide the best estimate of residue decay in New Zealand. There was no increase in carbon concentration with decay, suggesting that live stem values may be applied to all dead wood for determining the mass of carbon change with decomposition. Nitrogen concentrations increased with decay.

Techniques used to remove unwanted wilding conifers can impact on subsequent vegetation successions. Five South Island sites were assessed for vegetation successions after conifers had been removed by four methods, felled to waste, mulched, harvested or killed standing by stem poisoning. Felled conifers created a flush of vigorous plant growth, but this increase was not long-lasting, and the end result was reduced plant biodiversity. Mulching reduced all plant cover initially, but gave poor wilding control. Harvesting led to a dominance of exotics including wildings, whereas solely native plants were found under dead standing trees that had been poisoned. Results indicated that, while there were differences in vegetation composition between the low and high altitude sites, there are good opportunities for manipulating wilding control towards more desirable vegetation covers – particularly involving native plants.

The invasion of a high country grassland site (850 m asl) by lodgepole or contorta pine (Pinus contorta Dougl) wildings was monitored over 32 years in the Craigieburn Range Canterbury The first wildings appeared in 1975 By 1985 density had reached 34550 stems/ha with a mean height of 185 m and a basal area of 17 m2/ha By 2007 stocking had dropped to 11400 stems/ha with a mean top height of 143 m and a basal area of 104 m2/ha Thirtyeight plant species were present 10 years after wilding invasion started Twentysix species (68) were indigenous By 2007 the number of species present had dropped to seven none of which were indigenous The introduced tussock hawkweed (Hieracium lepidulum) featured in both assessments It was concluded that more species are likely to invade as the canopy opens up but if native species are wanted they may have to be introduced by artificial seeding

Wilding conifers are invading grassland and shrubland ecosystems in the New Zealand high country The felling of wildings is common practice to control such infestations This research investigated the effects of felled pines on growth and composition of grassland vegetation at Mt Barker Canterbury The vegetation within areas of dead trees felled in 1998 was compared with open grassland alongside Adjacent to the dead trees mean species number/plot was reduced to seven (native 37) compared to open grassland (134; native 109) Mouseeared hawkweed (Hieracium pilosella) was dominant in the open grassland plots and had very low cover inside the deadtree plots Grasses and native shrubs showed enhanced growth in the deadtree plots Average plant height was 213 cm compared to 54 cm in the open grassland plots It is suggested that novel microsites and additional nutrients from the decaying trees gave a competitive advantage to some plants for a period of time

The angle $\psi$ between a planet's orbital axis and the spin axis of its parent star is an important diagnostic of planet formation, migration, and tidal evolution. We seek empirical constraints on $\psi$ by measuring the stellar inclination $i_{\rm s}$ via asteroseismology for an ensemble of 25 solar-type hosts observed with NASA's Kepler satellite. Our results for $i_{\rm s}$ are consistent with alignment at the 2-$\sigma$ level for all stars in the sample, meaning that the system surrounding the red-giant star Kepler-56 remains as the only unambiguous misaligned multiple-planet system detected to date. The availability of a measurement of the projected spin-orbit angle $\lambda$ for two of the systems allows us to estimate $\psi$. We find that the orbit of the hot-Jupiter HAT-P-7b is likely to be retrograde ($\psi=116.4^{+30.2}_{-14.7}\:{\rm deg}$), whereas that of Kepler-25c seems to be well aligned with the stellar spin axis ($\psi=12.6^{+6.7}_{-11.0}\:{\rm deg}$). While the latter result is in apparent contradiction with a statement made previously in the literature that the multi-transiting system Kepler-25 is misaligned, we show that the results are consistent, given the large associated uncertainties. Finally, we perform a hierarchical Bayesian analysis based on the asteroseismic sample in order to recover the underlying distribution of $\psi$. The ensemble analysis suggests that the directions of the stellar spin and planetary orbital axes are correlated, as conveyed by a tendency of the host stars to display large inclination values., Comment: Accepted for publication in ApJ; 59 pages, 39 figures, 4 tables

To meet international greenhouse gas reporting obligations, New Zealand must report on carbon stocks in forests established after 1989 (post-1989 forest). Although predominately comprised of planted forest, post-1989 forest also contains a component of natural vegetation amounting to less than 10% by area. New Zealand undertook a national inventory of this natural stratum of post-1989 forest to provide estimates of carbon stocks and stock change in woody species over the first commitment period (2008–2012) of the Kyoto Protocol. Plots were installed on a 4-km grid, and the basal diameters and heights of trees and shrubs were measured for the first time from November 2012, to March 2013. Carbon stocks in 2012 were calculated using allometric functions developed from biomass samples from each site. Basal disc samples provided data on diameter increment and shrub and tree age annually from 1990 to 2012. These were used to predict carbon stocks per ha for individual plots in 2008 and to provide annual predictions by pool back to 1990. Carbon stocks summed across live and dead biomass pools (excluding soil) averaged 3.04, 16.70 and 28.73 t C/ha in 1990, 2008 and 2012, respectively. The disposition by pool was 2.25, 12.54 and 21.84 t C/ha in aboveground biomass, 0.56, 3.13 and 5.46 t C/ha in belowground biomass (using a root/shoot ratio of 0.25), 0.03, 0.17 and 0.23 t C/ha in deadwood, and 0.18, 0.86 and 1.21 t C/ha in litter in 1990, 2008 and 2012, respectively. In 1990, the woody biomass stock estimate per plot ranged from zero to 40 t C/ha and averaged 3.04 t C/ha across all plots. The methodology used to predict annual carbon stocks required an assumption concerning stem annual mortality. Sensitivity analysis suggested that varying this assumption had only a minor impact on predicted carbon stocks and changes. Plant age varied markedly within and between the natural forest plots, and therefore, the mean age of woody vegetation at each site was obtained by setting a threshold woody biomass carbon stock that needed to be achieved, and vegetation age was calculated as years since the threshold was achieved. This threshold approach facilitated the development of a yield table for predicting carbon (t/ha) as a function of vegetation mean age.

Meloidogyne incognita-infected and noninfected tubers of yellow nutsedge (Cyperus esculentus) and purple nutsedge (Cyperus rotundus) were treated with 56 L/ha 1,3-dichloropropene (1,3-D) in microplots and subsequently examined for tuber and nematode viability in the greenhouse using a chile pepper (Capsicum annuum) bioassay system. The study was conducted three times. Nutsedge tuber viability and M. incognita harbored in both yellow and purple nutsedge tubers were unaffected by 1,3-D treatment. Nematode reproduction on nutsedges and associated chile pepper plants varied among years, possibly due to differing levels of tuber infection or soil temperature, but was not affected by fumigation. The presence of M. incognita resulted in greater yellow nutsedge tuber germination and reproduction. The efficacy of 1,3-D for management of M. incognita in chile pepper production is likely to be reduced when nutsedges are present in high numbers, reinforcing the importance of managing these weeds and nematodes simultaneously.

Channel coding is playing an pivotal role for improving the performance of xDSL systems in terms of higher data rate and long loop reach. The current channel coding scheme for standard DSL concatenates Reed-Solomon (R-S) codes and multi-dimensional Trellis coded modulation (TCM) codes. Although RS-TCM coding provides a significant coding gain for DSL systems, this gain still far away from the channel capacity. Recently rediscovered low-density parity-check (LDPC) codes, which were invented by Gallager in 1962, have become the best-known practically implentmentable codes for closely approaching the channel capacity. The probabilistic decoding for LDPC codes is an effective and applicable technique based on the message-passing algorithm which employs probabilistic message-passing on a normal graph generated from the parity-check matrix of LDPC codes. Our empirical results showed that for flat AWGN channels and various Q AM modulation schemes more than 2.0 dB performance improvement of DSL systems was obtained with LDPC coding instead of the RS-TCM scheme. This thesis emphasizes the study of the performance of LDPC codes applied in xDSL systems operating on frequency-selective multilevel AWGN channels. Two different frequency selective channel models were used in our simulation studies, where bit-error rate (BER) was measured (via computer simulation) vs. received signal-to-noise ratio (SNR). LDPC codes were employed together with multilevel QAM in DMT-xDSL systems. Coding gains greater than 2.8 dB were obtained at 10~6 BER when compared with RS-TCM coding.

Meloidogyne incognita (Mi) reproduction and host plant responses in chile pepper (Capsicum annuum) and yellow nutsedge (Cyperus esculentus = YNS) to three sources of inoculum obtained by rearing a single Mi population on chile, YNS, and tomato were evaluated in two factorial greenhouse experiments. The interactive effects of Mi inoculum source and crop-weed competition were determined. In the absence of YNS competition, chile growth was reduced less by Mi inoculum from chile than by inoculum from YNS or tomato. When YNS was present, chile root weight was not affected and shoot weight increased with Mi initial inoculation, regardless of inoculum source. Chile plants inoculated with Mi from tomato exhibited double the nematode reproduction observed with inoculum from chile or YNS. With chile present, Mi reproduction on YNS was nearly three times greater with inoculum from tomato, but reproduction was similar among inoculum sources when chile was absent. Reductions in YNS root mass due to competition from chile failed to reduce the total number of Mi eggs produced on YNS plants. Differences in total Mi reproduction among inoculum sources were not attributable to differences in root growth or plant competition. This study illustrates the influence of Mi-YNS interactions and previous hosts on severity of Mi infection.

Field trials were conducted during 1986, 1988, 1989, and 1991 to compare the effects of 1,3-dichloropropene, fenamiphos, and carbofuran on yield and quality of chile peppers (Capsicum annuum) in soil infested with Meloidogyne incognita. When compared with untreated plots, numbers of M. incognita juveniles recovered from soil 60 and(or) 90 days after chile pepper emergence were reduced (P = 0.05) following 1,3-D treatment every year except 1986. Nematode numbers were also reduced (P = 0.05) by fenamiphos in 1989. Chile pepper yields were significantly higher than those in untreated control plots (P = 0.05) all 4 years in plots treated with 1,3-D and in 1989 in plots treated with fenamiphos. Use of carbofuran did not significantly reduce nematode numbers or enhance yields in these experiments. Green chile pepper fruit quality was enhanced (P = 0.05) following 1,3-D treatments in 1988 and 1989 but was unaffected by fenamiphos or carbofuran application. Increasing placement depth of 1,3-D from 28 to 48 cm increased (P = 0.05) red chile pepper yield compared with that obtained with conventional placement in 1988 only, and did not affect green chile pepper yield.

1. Sramek and Bernstein's method of impedance cardiography is a simple, non-invasive and inexpensive computerised way of measuring stroke volume and systolic time intervals. In this study measurements made using the method were compared with those found simultaneously using established reference techniques. 2. In healthy volunteers there was no significant bias (d) and narrow 95% limits of agreement (d +/- 2s) when impedance and mechanophonocardiographic measurements of pre-ejection period (PEP, d = 0.3, d + 2s = 7.3, d-2s = -6.6 ms), ventricular ejection time (VET, d = 1.5, d + 2s = 17.7, d-2s = 14.6 ms) and PEP/VET ratio were compared. 3. In critically ill patients there was moderate agreement between impedance and thermodilution measurements of stroke volume (d = 8.1 (P < 0.05), d + 2s = 35.5, d-2s = -19.4 ml) and drug-induced changes in stroke volume were accurately detected. 4. In healthy volunteers agreement between impedance and dye dilution measurements of stroke volume was moderate, and similar at rest and during exercise (d = 3.4, d-2s = -31.1, d + 2s = 37.9 ml), however impedance underestimated exercise-induced increases in stroke volume (P < 0.05). 5. In patients with coronary heart disease impedance measurements correlated with angiographic left ventricular ejection fraction included the PEP/VET ratio (r = -0.81), stroke volume index (r = 0.65) and Heather index (r = 0.58, all P < 0.001), however the PEP/VET ratio could not be used to estimate the left ventricular ejection fraction with sufficient accuracy. 6. This impedance method provides reproducible semi-quantitative measurements of cardiac performance and blood flow. Its use for making pharmacodynamic measurements can be justified when invasive methods are considered inappropriate.