scholarly journals A review of kowhai (Sophora spp.) and its potential for commercial forestry

2021 ◽  
Vol 51 ◽  
Author(s):  
Lisa Nguyen ◽  
Karen Bayne ◽  
Clemens Altaner

Background: Demand for imported sawn timbers in New Zealand has increased over the last decade, reflecting the lack of New Zealand-grown, naturally durable timber in the domestic market. Therefore, a market opportunity exists for sustainably grown, naturally durable timbers in New Zealand for specialty applications. Kowhai (Sophora spp.) are New Zealand native tree species, known for their bright, yellow flowers and reported to produce coloured, naturally durable heartwood.Methods: Information on kowhai was collated from literature, focusing on their potential for commercial forestry. The taxonomic relationships, species descriptions, establishment, and growth rates of kowhai were examined, along with timber properties and historical uses, as well as medicinal applications. The review identified potential market opportunities for kowhai and key areas for further research.Results: Kowhai refers to eight different Sophora species that are endemic to New Zealand. Kowhai is easily established and the different species hybridise readily. While growth and form of kowhai varies with species, site, and management, examples of straight single-stemmed trees and annual diameter increments exceeding 20 mm have been found. Kowhai timber properties might be comparable to those of teak (Tectona grandis L.f.). Kowhai contains alkaloids, a class of compounds used in pharmaceutical applications. The species have been used for timber and traditional medicine by Maori in the past, while European settlers used kowhai for their durable and flexible timber.Conclusions: Kowhai could be established as a sustainable, domestic source of high-quality timber and substitute imported specialty timbers in New Zealand on account of their natural durability, strength, stiffness, colour, and density properties. The residues could support a secondary industry, as a source of alkaloids for pharmaceutical applications or natural dyes. Key areas that require further study include growth rates and silviculture, mechanical timber properties, machining/processing characteristics, natural durability and cytisine levels in kowhai, as well as the cultural, economic, and ecological framework required for a commercial kowhai forestry industry. Lack of literature on, and expertise in the use of native timbers in general are barriers to promoting native species for commercial forestry in New Zealand.

2020 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.


2021 ◽  
Author(s):  
◽  
Guyo Duba Gufu

<p>Biological invasion by non-native plant species has often been cited as a cause of native biodiversity loss. While the outcome of species invasions depends on interactions between exotic and resident native species, most studies of biological invasions have focused solely on the direct negative impacts of non-indigenous species on native biota. Although investigations of the role of competition in shaping natural plant communities were dominant in the previous generations and are still popular, more recent experimental research has uncovered the striking influence of facilitation on community dynamics. This thesis aims to investigate competitive and facilitative influence of the invasive South African iceplant (Carpobrotus edulis) on Spinifex sericeus, a native foredune grass species, with particular reference to implications of these interactions for dune restoration in New Zealand. It further explores the growth rates, substrate preferences and mating systems of the exotic and native iceplant taxa found in New Zealand. I begin by briefly outlining the influence of competition and facilitation on natural plant communities with reference to the role of facilitation in eco-restoration. I also give a few examples where exotic species have been found to facilitate native ones. Secondly, a neighbour removal experiment was conducted on coastal sand dunes with the main aim of studying the effects of Carpobrotus edulis on establishment of Spinifex sericeus at the foredune region. Finally, I compared the growth rates of the most widely distributed iceplant taxa in New Zealand in different substrates and the breeding systems of the exotic Carpobrotus.  Examples abound in literature of exotic plant species facilitating native ones especially in forestry. In the neighbour removal study, Carpobrotus edulis protected Spinifex seedlings against storm erosion, sandblasting and salt sprays while at the same time suppressing its leaf production. Suppression of Spinifex leaf production was more pronounced at top of the dune where stress elements is presumably more benign. There was no evidence of allelopathic suppression of Spinifex by C. edulis. Only Carpobrotus chilensis displayed some level of substrate preference by putting on relatively lower biomass in gravel. The exotic Carpobrotus spp. put on greater dry matter content than the native Disphyma australe and the Carpobrotus-x-Disphyma hybrid. The hybrid displayed a faster vegetative growth rate whereas D. australe allocated relatively more biomass to the roots than the shoot. Both Carpobrotus spp. are self compatible and highly capable of intrageneric and intergeneric hybridisation. Mass removal of the existing exotic iceplant stands from foredunes along high energy coasts is not advisable as they serve as useful stabilisers. The intergeneric hybrid is sexually sterile with sparsely spread stolons that could allow co-occurrence with other species and therefore is more suitable for foredune stabilisation. However, more research needs to be conducted on the ecology of the intergeneric hybrid.</p>


2021 ◽  
Author(s):  
◽  
Kirill Woodhouse

<p>Exotic species often slip through international borders undetected. Many perish but for some species introduction to a foreign land or sea brings release from natural enemies and a chance to establish a population. Increased global trade has increased the frequency of species introductions through stowaways and lapses in biosecurity. Once an invader is established there is the opportunity for explosive population growth at the detriment of native species and humans. The marine aquarium trade is a significant vector of species introductions, including algal introductions. The most publicized introduction from aquaria was the release of the green alga Caulerpa taxifolia from the Oceanographic Museum in Monaco. C. taxifolia introduction had large negative impacts on the invaded ecosystem.  Molecular barcoding of tropical macroalgae entering the New Zealand aquarium trade was implemented using various molecular markers (cox1, cox3, rbcL tufA, LSU). Both NCBI Blast searches and maximum-likelihood phylogenies were used to identify the isolates. A total of 62 species of tropical macroalgae were identified from coral rocks imported into New Zealand, plus samples from reef hobbyists. Some species found are known as invasive elsewhere, for example, Caulerpa cylindracea, C. racemosa, C. sertularioides, Ulva ohnoi and Chaetomorpha vieillardii. All three major groups of algae were well represented in my findings with 26 species of red algae, 24 species of green algae and 12 species of brown algae. Temperature tolerance limits are the largest determinant in survival in algae, while salinity and pH are less significant. Temperature tolerance of tropical algae to the minimum Sea Surface Temperature in Auckland (14°C) and Wellington (11°C) was tested. My results show that one species Chaetomorpha vieillardii can survive at Auckland minimum winter sea surface temperatures. Our findings have important implications for New Zealand biosecurity, as not only are a large diversity of exotic macroalgae entering the New Zealand marine aquarium trade unregulated, but there is also the potential for them to survive in New Zealand waters.   </p>


Zootaxa ◽  
2019 ◽  
Vol 4623 (3) ◽  
pp. 441-484
Author(s):  
SABINE MELZER ◽  
ROD A. HITCHMOUGH ◽  
TRENT BELL ◽  
DAVID G. CHAPPLE ◽  
GEOFF B. PATTERSON

New Zealand has a diverse skink fauna, comprising 45 described native species, and at least 15 undescribed taxa, within the single genus Oligosoma Girard, 1857. One of the earliest described, and best known, species is the speckled skink, Oligosoma infrapunctatum (Boulenger 1887). Despite a relatively stable taxonomic history for nearly 114 years, recent molecular work has indicated that O. infrapunctatum represents a species complex, comprising numerous genetically divergent, range restricted taxa. We completed the first stage of a taxonomic revision of O. infrapunctatum, conducting a morphological re-evaluation of existing voucher material, and newly collected specimens, and generated a molecular phylogeny for the species complex. This allowed us to distinguish six species: O. infrapunctatum, two species resurrected from synonymy (O. newmani, O. robinsoni), and three new species (O. salmo sp. nov., O. albornense sp. nov. O. auroraensis sp. nov.). The name bearing type population of O. infrapunctatum has not been located again for at least 130 years: it remains to be rediscovered and may already be extinct. Two of the six species here are considered ‘Nationally Critical’ (O. albornense sp. nov., O. salmo sp. nov.) under the New Zealand Threat Classification System, the others are Nationally Vulnerable (O. auroraensis sp. nov.) and At Risk—Relict (O. newmani, O. robinsoni). Further taxonomic work will be required to determine the taxonomy of other speckled skink genetic lineages in the South Island, particularly O. aff. infrapunctatum “cobble”, O. “Hokitika”, O. “Southern North Island” and O. “Westport”. 


2018 ◽  
Vol 10 (9) ◽  
pp. 3166 ◽  
Author(s):  
GwanSeon Kim ◽  
Jun Seok ◽  
Tyler Mark

This paper investigates what factors and characteristics of organic consumers affect annual organic food expenditure by using Nielsen’s consumer panel dataset from 2010 to 2014. To be specific, this paper explores new marketing opportunities by investigating organic consumer heterogeneity in different household income levels by utilizing the multilevel model. Findings in this study will contribute to the previous and existing literature in three-folds. First, we find that the organic consumers are more heterogeneous in the high-level of income groups (approximately above $60,000), as well as the low-income households between $35,000 and $45,000. This finding demonstrates that the income levels above $60,000 and around $40,000 have potential market segmentation. Second, we find that that annual organic expenditure is positively associated with consumers who consecutively repurchase organic food products compared to irregular organic consumers, supporting a different level of satisfaction. Third, we find that USDA organic labeling has a positive effect on annual organic expenditure compared to the organic labeling certified by private companies, implying the importance of credibility for the organic labeling.


2012 ◽  
Vol 18 (2) ◽  
pp. 77 ◽  
Author(s):  
Heather Parks ◽  
Kyle Clifton ◽  
Lauren Best ◽  
Bridget Johnson

PEST-PROOF (exclusion) fences are designed to prevent non-native, predatory and pest species from repopulating an area set aside to protect vulnerable native plant and animal species. Pest-proof fencing provides security from invasive species, but can isolate the native species enclosed within. On one hand, some rare native species exist on the mainland due to the pest-free status achieved through the use of exclusion fences. On the other hand, these reintroduced populations are now isolated a situation where they would not be found naturally (Jamieson et al. 2006). Exclusion fences must be constantly maintained or the sanctuary risks reinvasion. An important question for conservation biologists and managers to answer is therefore — when is exclusion fencing the best option for protecting native species from introduced pests? We have drawn our examples from New Zealand and Australia where progress has been made with regard to the design and utilization of exclusion fences.


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