Tuatara
Journal of the Biological Society
Victoria University of Wellington
New Zealand
Victoria University of Wellington
New Zealand
Volume17
Part2
October1969
Tuatara aims to stimulate and widen interest in the natural sciences in New Zealand, by publishing articles which, (a) review recent advances of broad interest; or (b), give clear, illustrated, and readily understood keys to the identification of New Zealand plants and animals; or (c), relate New Zealand biological problems to a broader Pacific or Southern Hemisphere context. Authors are asked to explain any special terminology required by their topic. Address for contributions: Editor of Tuatara, c/o Victoria University of Wellington, Box 196, Wellington, New Zealand. Enquiries about subscriptions should be sent to: Business Manager of Tuatara, c/o Victoria University of Wellington, Box 196, Wellington, New Zealand.
Contents
(This issue edited by
Tuatara
is the journal of the Biological Society, Victoria University of Wellington, New Zealand and is published three times a year. Joint Editors:
Botany Department, Victoria University of Wellington, New Zealand.
Now at the Research Division, Ministry of Agriculture and Natural Resources, Ibadan, Nigeria.
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Introduction
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Terms and definitions
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Methods used in measuring primary productivity.
Direct method
Indirect methods.
The gaseous exchange method.
Use of leaf area as an index of productivity.
Use of chlorophyll content as an index of productivity.
Use of a fraction of total production.
Use of albedo as an index of productivity.
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Published accounts of productivity.
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Efficiency of utilisation of solar energy.
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Organic turnover and chemical cycling.
The organic — inorganic cycle.
Accession of chemicals into the ecosystem.
Losses of chemicals from ecosystem.
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Abstract
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References
In recent years, exhaustive reviews of literature on organic production, turnover, and nutrient cycling in woodland ecosystems have been made, by Ovington (1962, 1965), Westlake (1963),
Rodin and Basilevic (1966), Basilevic and Rodin (1966), Duvigneaud and Denaeyer de Smet (1964). No attempt will be made here to write another detailed review so soon after these, but gaps can be filled in and literature brought up to date, particularly for New Zealand.
Because scientists in various disciplines (Agriculture, Forestry, Biology and Oceanography) are interested in measuring productivity, various terms are currently being used to define parameters of production. Ovington (1962) Odum (1959) and Westlake (1963) have each attempted to standardise these terms, but such standardisation has not yet been achieved. The key words i production ecology are biomass, production and productivity, words often freely used, with little thought to meaning. The definitions given below are based partly on those of Ovington (1962) and Westlake (1963).
Biomass:— is the total weight of organic matter, both living and dead, present on a unit area of the ecosystem at any given time. In usage, the word should refer specifically to the plant (phytomass) or animal (zoomass) part of the biomass, except where one is interested in the combination of both. However, the practically measurable plant biomass includes undecomposed litter which may be harbouring litter fauna.
There has been some discrepancy in the definition of ‘biomass’. Zoologists and limnologists have defined it as the living mass (Odum, 1959; Macfadyen, 1963), while botanists and foresters have defined it as the total organic matter, living and dead (Ovington, 1962). Such discrepancy arises from the fact that in zoological and limnological studies, organic matter may be rapidly dissolved or consumed by scavengers as soon as it is dead and may not accumulate as it can in the terrestrial ecosystem. Limiting ‘biomass’ to the living component in terrestrial ecosystem studies is difficult, since it is not often easy to distinguish between living and dead organic matter. For example, how can one separate a dead tracheid or xylem fibre in the heart of wood of a tree when measuring the biomass of the trunk?
Primary production:— refers to the total organic matter produced as a result of photosynthesis and nutrient uptake from the soil. The ‘primary’ preceding production is used to distinguish it from production at the second trophic level (consumption). the conversion of plant organic matter into the body tissue of animals. Primary production is referred to as gross primary production when all organic matter including that used in metabolism is taken into consideration. Often, however,
net primary production which can easily be measured. The latter is sometimes referred to as apparent photosynthesis or surplus production. Net primary production is defined as the quantity of organic matter produced over a period of time, less that used in metabolic processes, and including all losses due to litter fall, root sloughing, grazing, and fruit or seed production during that period.
Primary productivity:— is primary production expressed as a rate. For example, if the net primary production is x/kg per hectare within the period of t, then the net primary productivity is x/t kg per hectare per unit of time. Productivity is expressed as dry weight, total carbon, nitrogen or total energy fixed per unit area of the ecosystem per length of time: kg/ha./an. or Kcal/ha./an. Often the terms ‘production’ and ‘productivity’ are used synonymously. No confusion arises when net primary production is measured per unit of time, e.g. ‘pasture production in a paddock in 1965 was 20,000 kg/ha.’ could be expressed as 20,000 kg/ha./an., but if the pasture production was for 1964 and 1965, then productivity becomes 10,000 kg/ha./an. This is commonly referred to as the mean annual net primary productivity, and is the average rate of dry matter production by the ecosystem.
Many published results of rates of organic matter accumulation by tree stands have been expressed as means. Usually, such means are obtained by averaging biomass over stand age. These calculations cannot give good measures of the rate of organic matter accumulation per year since growth rate varies from year to year in the life of a plant and biomass is subject to continuing losses by litter fall and grazing. Such losses are not taken into account in the determination of biomass at the end of a period of several years. The best measure of primary productivity, especially in perennial plants, is the current annual net primary productivity. The current rate of organic matter production changes from year to year, especially in the early years of tree plantations, and shows different patterns for different species.
Ovington (1962) has brought out clearly the differences between current annual and mean annual net productivity.
Economic, agronomic and biological productivity:— In forestry and agriculture, only the economic parts of plants or crops are harvested, e.g. tree boles are removed in forestry grains, tubers and fruits in cropping. Productivity calculated from the economic harvest alone is referred to as economic productivity (Ovington, 1965) and agronomic productivity (Pearson, 1965). It is apparent that productivity based on the calculations from economic harvest would seriously under-rate productivity values. On the other hand, the difficulty of complete harvesting of roots makes it extremely difficult to determine biological productivity accurately.
The terms ‘standing crop’ (= easily extractable biomass),
The methods in general use in the measurement of biological primary productivity in terrestrial ecosystems have recently been summarised by Woodwell and Bourdeau (1964), Leith (1964), and Newbould (1967). These methods fall into two types; direct and indirect.
The direct method is based on biomass determined by harvesting and weighing of all organic matter present in a unit area of the ecosystem.
Variations of this technique have been used, depending on the nature of the vegetation to be sampled. For example, in herbaceous ecosystems, grasslands and low-growing perennials, clipping of quadrats has been used e.g. Pearsall and Gorham 1956; Odum, 1960; Ovington et al. 1963; Welch and Rawes, 1965; Robertson and Davis, 1965; Westlake, 1966. To obtain reliable figures of productivity in herbaceous vegetation and grasslands, it is necessary to clip the growth at its maximum biomass before losses start to occur. It is not easy to determine when the vegetation reaches its maximum biomass. Westlake (1963) suggested that maximum biomass is attained at about the seeding stage. This is only true of situations where only one species is involved; different species growing together may reach seeding at different times of the season. When the biomass of herbaceous vegetation is determined at the end or near the end of the growing season, the results can be corrected for productivity by adding the weight of losses in litter fall and grazing, but the latter in turn is difficult to determine.
The clipping technique of course is not suitable for measuring the biomass of forest stands. In one case however, Greenland and Kowal (1960) clear-felled an acre of a 40 year secondary tropical forest in Ghana, and determined the biomass. This is a tedious and very expensive operation.
Various time-saving techniques, based on the analysis of one or a few trees are, therefore, employed to assess biomass of tree stands (e.g. Ovington, 1958, 1960; Miller, 1963; Will, 1964; etc). Ovington and Madgwick (1959) compared the effectiveness of three such techniques:—
Harvesting a tree of average bole girth for the stand, obtaining its biomass, and extrapolating to estimate the biomass of the stand. Dividing the trees within a stand into girth classes and harvesting trees of average girth in each class, and again extrapolating to estimate biomass of the stand. Technique of every tree summation. A few trees are harvested and the biomass of various components obtained. The results of these are used to draw regression or correlation equations which relate the biomass of tree components (e.g. leaves, branches, etc.) to readily measured parameters (e.g. girth or diameter at breast height). Using the regressions, the biomass of individual trees and hence, that of the tree stand can be estimated. Recently. Baskerville (1965) used similar techniques to estimate biomass of a stand of balsam fir, and calculated possible errors likely to arise by using such methods. Ovington and Madgwick (1959) observed that method (i) gave consistently low results compared with methods (ii) and (iii). It is obvious from this that the so-called tree of average dimensions may not truly be average, for a tree which is average in girth may not be average in other respects.
The techniques discussed above are unsuitable for multistoried natural ecosystems. A few workers have attempted to develop techniques suitable for such ecosystems. Kuroiwa (1960) estimated net annual production of a stand of Abies mariessi by formulae to determine the annual increment due to needles and branches, based on the number of leaves, mean leaf weight, and decrease of leaf number with age. For stem increment he based his formulae on the volume increment between two time intervals, using wood density to estimate weight. Whittaker (1961), working with Rhododendron maximum also estimated total net production by techniques based on various growth parameters. He determined conversion factors between: (a) total net production and current shoot production (b) shoot production and stem wood increment (c) stem wood increment and estimated volume increment.
Pearson (1965) estimated annual production in a different way using partially empirical formulae based on tree dimensions such as radius of trunk at base, height of tree, depth of tree canopy and the numerical density of the species studied.
In view of the difficuties encountered in measuring productivity in complex multistrata perennial ecosystems, a number of indirect methods have been and are still being developed to measure productivity.
A summary of these is presented:
Following the success of plant physiologists in using rate of gas exchange as a measure of photosynthesis, many ecologists and whole-tree physiologists have attempted to measure production in plant communities using similar techniques (Saeki, 1960; Nomoto et al. 1959; Nomoto, 1964; Golley, 1965.) Nomoto (loc. cit.) measured photosynthesis and respiration rates of sun and shade leaves of beech (Fagus sylvatica) in chambers. From his results, making use of leaf quantity, leaf area index (L.A.I.), photosynthesis and light and temperature curves, he derived equations from which he estimated daily and monthly net production for the six months (May to October) of the growing season.
In recent years, complex gas analysers have been used to measure carbon dioxide exchange in detached leaves, excised leaves or attached branches (Bordeau and Woodwell, 1964, and Golley, 1965.) The limitations of such a technique are many: Enclosing leaves or branches in chambers places them in artificial conditions which differ from the ones in which they normally photosynthesise. However, various devices e.g. cooling the chamber, reducing the humidity, may be used to simulate a normal environment. Although this method gives the added advantage of measuring gross production, it is too great a generalisation to extrapolate from the activity of single leaves or even branches to arrive at that of thousands of others in a plant community.
Since the leaf area available for absorbing the incident light will, to a certain extent, determine the rate of photosynthesis, some workers (Watson, 1958; Takeda, 1961: Brougham 1960; Davidson and Donald, 1958; Black, 1963; Rees, 1963;) have attempted to find whether any relationship exists between leaf area and the rate of dry matter production.
Their results indicate that up to a particular value, depending on the plant species, there is a concomitant increase in productivity with increase in leaf area index (L.A.I.) —which is the leaf area per unit of land area. But beyond this value, which has been referred to as ‘optimum leaf area index’ (Kasanaga and Monsi, 1954), there is no further increase in production with increase in leaf area index due to mutual shading. In fact, it has been shown (Watson, 1958; Kanda and Sato, 1963) that at values of L.A.I. above the optimum production declines because of respiratory losses of leaves growing in light intensities below the compensation point, where respiration exceeds photosynthesis. Except perhaps in pasture studies and early stages of growth in trees, L.A.I. cannot be used as an accurate measure of productivity.
The use of chlorophyll as an index of productivity originated from studies on marine production, and seems to have given reliable results on total biomass and productivity of phytoplankton (Manning and Juday, 1941; Harvey, 1950; Ryther and Yentch, 1957). The application of this method in terrestrial ecosystems has been attempted by Bray (1960, 1962). Bray's results indicated that in certain herbaceous species a highly significant correlation (r = +0.82, p <0.01) exists between chlorophyll and dry matter production. Brougham. (1960) also found a highly significant correlation between maximum growth rates and chlorophyll content in field crops.
While this relationship may be of interest in herbaceous ecosystems, it does not appear a feasible method for predicting the productivity of tree or shrub ecosystems.
Often, total production has been estimated from production of only a part or parts of trees, e.g. estimating roots from the values of top growth, or total production from quantity of leaf litter. Bray and Gorham (1964) have shown that the yearly litter production cannot be used as an index of productivity.
In addition to the methods described above, an attempt has been made to use albedo (i.e. the ratio of the amount of light reflected from the landscape to the total amount falling upon it) as an index of production. As a corollary from his studies on chlorophyll content as an index of productivity, Bray (1961) attempted to find whether any relationship existed between visible albedo and chlorophyll content. He postulated that if albedo could be used as an index of chlorophyll content, it could in turn be used as index of productivity. Working on a series of vegetation types in Minnesota, U.S.A., he established that there was a significant correlation between albedo, chlorophyll concentration and net productivity in upland stands with complete cover.
This method is more of academic than of practical value since the reflection of light from surfaces is dependent on many factors.
Although the harvest method does not take account of respiratory losses, and would under-estimate productivity if losses in litter fall and grazing were not taken into account, it offers the easiest method of measuring productivity in terrestrial ecosystems. The measurements of primary productivity in uneven aged, multistrata forest ecosystems is still a difficult proposition. There is broad scope for the development of new techniques. The methods of Whittaker (1961.) and Pearson (1965) show some promise in this line.
Productivity data have been published for various localities of the world, from arctic and arctic-alpine to the tropical regions, and the data reviewed, notably by Ovington (1962. 1965); Westlake (1963); Rodin and Basilevic (1966). For various reasons, comparisons of data from various parts of the world are difficult to make. Apart from the fact that the methods of measurement have often differed, results are often expressed in different ways: fresh weight, oven - dry weight, organic carbon, or ash free dry weight. To compare results expressed in these various ways, conversions have to be made before comparisons are valid. Westlake (1963) commented on the difficulties encountered in comparing results when various criteria have been used in expressing them. Despite these short-comings, Westlake, metric ton = 1000 kg.(loc. cit.) has attempted to make comparisons of productivity for ‘maximum’ sites from various biocenoses—such as phytoplanktons, marine macrophytes, herbs, forests and cultivated plants. His maximum sites were those with the highest recorded data for each of the biocenoses. From Westlake's conclusions and those of Bazilevic and Rodin (1966) and Odum (1959) there is a general agreement that the highest production is in the humid tropics, and the lowest in the arid deserts. Westlake gave a probable mean annual net productivity of 50 ± 20 tons
Production ecology is comparatively young in New Zealand. Even though there is much data on yield of pastures and exotic forests, emphasis has been on the agronomic or economic production and there are few published accounts of biological productivity. The following table gives a summary of published studies.
The most productive of the communities studied was the Pinus radiata stand growing on pumice derived soils. It's high productivity has been attributed to its evergreen nature and its long growing season.
It is hoped that more data will be available at the conclusion of the International Biological Programme in which New Zealand is a participant.
The production and accumulation of organic matter by autotrophs in an ecosystem is also a fixation and accumulation of energy within it. The source of this energy is solar energy, which is converted into chemical energy in the process of photosynthesis.
The energy thus fixed is the motive force that drives the ecosystem and sets a limit to its dynamics. Therefore, the efficiency with which autotrophs convert solar energy into chemical energy is an important factor in the study of ecosystem energetics. This efficiency, which is known as the photosynthetic efficiency, is the ratio of energy fixed in the autotrophs, to the light energy reaching them over the same period. Because of the lack of standardisation of the terms of the ratio, calculations of photosynthetic efficiencies have been based on various measurements. For example photosynthetic efficiencies have been calculated from the energy contained in gross production (Golley, 1960; Bray, 1961), and from the energy contained in net production (Hellmers and Bonner 1959; Ovington and Heitkamp, 1960; Ovington 1961; Will 1964; Minderman, 1967). Some photosynthetic efficiencies have been based on the total incident light energy (Ovington 1961; Minderman 1967), and many on photosynthetically active radiation (Bray, 1961; Golley, 1960; Wassink et al. 1953, Wassink 1958; Hellmers and Bonner, 1959). Bray (loc. cit.) calculated efficiency from the photosynthetically active radiation after allowing for non-pigmented absorption, transmission and albedo.
One reason for the lack of standardisation is the difficulty of measuring solar energy. In some earlier studies e.g. Ovington
2 in June to 436 cal.cm2 in December.
Although most solarimeters measure the total insolation, only visible light (approximately 400/mic. to 70/mic.) is used in photosynthesis and this fraction is not constant but varies with weather conditions. Recently, McCree (1966) described a modified solarimeter which measures only the photosynthetically active radiation (P.A.R.). At Lower Hutt, New Zealand, he estimated that P.A.R. varied between 48 per cent in bright light to 68 per cent in overcast weather. When calculations are based on the visible light only, it is usual to assume that the fraction is about 50 per cent of the total solar radiation. Bray (1961) estimated the fraction at 48 per cent, while Moon (1940) estimated it at 44 per cent.
Comprehensive reviews of data on efficiency of light energy utilisation by crops and forest have been made by Wassink (1959). Blackman and Black (1959), Hellmers and Bonner (1959) and Hellmers (1964).
Blackman and Black's estimates of photosynthetic efficiency for some field crops in England are considered high when compared to those of other workers. For example he estimated a value of 9.5 per cent for Beta maritima, whilst Wassink recorded a value of 1 to 2 per cent for field crops in Holland, and Heller and Bonner recorded values of 2 to 3 per cent for forest trees in Europe.
In New Zealand, Will (1964) using Penman's formula to estimate available light energy, recorded a photosynthetic efficiency of 3 per cent for Pinus radiata. Egunjobi (1967) recorded 0.4 per cent for unfertilized mixed pasture, 1.1 per cent for fertilized pasture and 1.7 per cent for a mature Ulex europaeus stand. Recalculating Will's data from measured solar energy at Taita, the photosynthetic efficiency of the pine stand would be 2.2 per cent This figure will be higher than those quoted by Hellmer and Bonner (Loc. cit) for forest stands if calculation is based on the production and insolation during the actively growing period as in the latter case.
It is obvious that photosynthesis is an inefficient process. The highest efficiencies are recorded under very low light intensities.
For example during September 1966 (P.A.R. = 4410 × 105 Kcal./ha.) the photosynthetic efficiency in mixed pastures at Taita was 1.8% whereas during the warmer summer month, December, with P.A.R. of 6750 × 105 Kcal./ha. and higher dry matter production, the efficiency was 1.4% (Egunjobi 1967).
In the natural sequence of growth and development, large amounts of the organic matter accumulated in wood ecosystems die off and return to the soil as litter. Linked with this organic turnover is the biogeochemical cycle, in which chemicals removed from the soil by plants for growth are variously returned to the soil to be reabsorbed into the organic-inorganic systems later, or to be lost to the ecosystem.
The various paths of chemical cycling in woodland ecosystems have been enumerated by Ovington (1962. 1965) and Bormann and Likens (1967). Various aspects of these cycling processes have interested different workers. The cycling of chemicals in terrestrial ecosystems may be discussed under the following headings:
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Organic — inorganic cycle (intrasystem cycle of Bormann and Likens 1967).
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Accessions (inputs)
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Losses (outputs)
The aspect in the chemical cycling processes of woodland ecosystems that has been most studied is litter fall. The importance of litter in woodland ecology has been known for almost a century. In 1876, Ebermayer drew attention to the role of forest litter in forest nutrition. Since then many papers have been published on the production and chemical composition of forest litter. In New Zealand Miller and Hurst (1957) and Will (1959) have provided data for litter in native beech forest (Nothofagus truncata) and in Pinus radiata planted forest. In a recent review, Bray and Gorham (1964) reviewed most of the litter studies in the world. Ovington (1965) has shown that in mature tree ecosystems, more nutrients return to the soil in litter annually than are immobilised in the wood. For example more than 80% of most of the nutrients removed by Nothofagus truncata is returned annually in litter fall (Miller, 1963). A similar study made on Ulex europaeus by the author (Egunjobi. 1967) shows that over 70% of the estimated total uptake of Ca, Mg, S, and Si and about 66% of Na and N were returned annually in litter fall and recretion — leaf leaching.
Other cycling processes connected with the organic cycle are root excretion (which cannot easily be measured) and root decomposition on which very little is known. The only published
In a grazed pasture, the cycling processes take a different path. Only small quantities of nutrients return to the soil in the organic turnover, while most return in the faeces and urine of the grazing animals. Sears et al (1942, 1948) and Davies et al (1962) have attempted to measure these processes by harnessing the animals with devices that collected faeces and urine. A comprehensive review of nutrient cycling under grazing has been made by Dale (1963). In all cases, very large fractions of the ingested nutrients are returned in the urine and faeces. For example Davies et al. (loc. cit) recorded that over 80% of the Mg, K and Na, and about 80% of Ca, and 60% of P ingested by dairy cows are returned to the soil annually in this way. The mobility of animals of course leads to the chance that nutrients from one part of the ecosystem may be excreted in another part, or even in another ecosystem.
It is also known that chemicals are leached out of living leaves and plant materials by rain (Stenlid. 1958). The quantities of nutrients in throughfall — i.e. rainfall not intercepted by the vegetation canopy — in woodland ecosystems have been determined in various places, eg. New Zealand (Will, 1959; Miller, 1963; Egunjobi, 1967). South Africa (Mes 1954), Sweden (Tamm, 1951), Ghana (Nye, 1961), Britain (Carlisle et al 1966) Australia (Attiwill, 1966). None of the published work has indicated what fraction of the chemicals in throughfall is due to leaching of nutrients from the canopy. It is difficult to assess this separately since the chemicals in throughfall are an accumulation of what is leached from the foliage, together with washings of particulate matter deposited on the surface of the foliage, and the atmospheric particles in rain. There are indications that a considerable amount of potassium in throughfall is due to foliar leaching.
Chemicals are added to the ecosystem in rain. The source of these chemicals are atmospheric particles which are washed down in rain drops. The origins of these particles may be oceanic, terrestrial, and extra terrestrial (Attiwill, 1966). There are many records of rainfall analyses, which assess the quantities of nutrients coming into the ecosystem in this way. As far back as 1888, Gray (1888, 1910) recorded the amounts of chemicals in rainwater at Lincoln, New Zealand. A considerable interest has been shown in atmospheric chemistry in the past two decades, and data on the chemical composition of rain water are now available for most geographical regions, e.g. for Western Europe (Eriksson, 1952a, 1952b.; Emmanuelson et al 1954; Madgwick and Ovington, 1959)
The composition of rain water is greatly influenced by the distance from the sea (Hutton and Leslie, loc cit), proximity to industrial sites and cities and the direction of the prevailing winds.
Other sources of addition of nutrients to the ecosystem are through rock weathering, deposition of products of erosion as in a flood plain, or hill slope and the artificial application of fertilizers.
Chemical elements are lost from the ecosystem in soil leaching, surface run off, forest fires, grazing and harvesting of crops. The least documented in the field of ecosystem processes is the study of nutrient losses. Lysimetric studies have been carried out in green house experiments to illustrate movement of chemicals out of soil columns. Viro (1953) Remezov (1961) and Crisp (1966) have attempted measuring chemical losses in drainage by analysing stream-water from catchments. The main difficulty about the interpretation of such analyses is that the composition of water leaving the ecosystem may change by solution or absorption as it moves through the strata between the ecosystems and the stream. Bormann and Likens (1967) gave an elaborate account of how hydrological measurements could be studied together with the measurements of chemical inputs and outputs in an ecosystem. At best, such measurements will be approximations, because of the complexity of watersheds, and of the fact that the bed rock of the watershed is often not impermeable. Borman et al. (1968) have recently published data on nutrient losses on a practically impermeable bed rock.
Forest fires constitute a drain on the nutrient capital of woodland ecosystems. Either by design or by mistake, large tracts of forest are burnt yearly in many parts of the world. Losses of nutrients due to forest fires are hard to assess. Published accounts by Allen (1964), Robertson and Davies (1965) indicate that on the average, over two thirds of the plant nutrients immobilised in a ten year old Calluna vulgaris stand were lost in burning. With the exception of nitrogen and sulphur, this cannot be considered a loss from the ecosystem. It is known, from studies of soil changes following burning (Miller et al. 1955), that the soil is enriched by the mineral ash of the burnt plants.
Grassland farming for meat, milk and wool production constitute some drain on the nutrient capital of the ecosystem. These losses are difficult to measure quantatively. Robertson and Davies (1965) estimated the losses of nutrients from sale of stock grazing on Calluna vulgaris at about 1 kg/ha, for calcium, phosphorus and 2 kg/ha, for nitrogen respectively over a ten year period. The
et al. 1962).
Nutrients are lost from the ecosystem in timber production. Ovington (1959) estimated possible losses of nutrients, due to harvesting of Pinus sylvestris L. in Britain, and concluded that calcium losses may be considerable.
Although there are vast amounts of data on the various aspects of mineral cycling, there are only a few integrated studies. Only such integrated studies, involving input and output into and from the ecosystem can be of real value in ecosystem studies.
Studies on primary production and solar energy utilisation by terrestrial plants, together with related studies on organic turnover and nutrient cycling are reviewed, paying particular attention to those made in New Zealand. The terms biomass, production, and productivity commonly used in production ecology are defined. Methods generally employed in measurement of primary production in terrestrial ecosystems are critically reviewed.
Difficulties of comparing published data are discussed. Records from New Zealand show that Pinus radiata is the most productive, with an estimate of 35 m.t/ha./an. for a site quality class one.
There are too few published studies on the efficiency of solar energy utilisation by plants in New Zealand. Because of lack of a standard method in measuring parameters on which efficiencies are calculated, published data are hard to compare.
Under woodland conditions over two thirds of the elements removed annually for plant growth are returned in organic turnover and ‘recretion’. In grazed pastures similar amounts of the nutrient uptake are returned in faeces and urine of the grazing animals. There is an input of nutrient into the ecosystem in rainfall, the magnitude and composition of which depends on proximity to cities, industrial sites, seas and oceans. Other natural inputs come from rock weathering and deposition of products of erosion. Losses of elements occur in leaching, run-off water, forest fires, timber removal, and cropping. Many of these losses are difficult to measure quantatively. There is a need for integrated studies involving input and output of minerals into and from an ecosystem.
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Glyceria maxima.1. Seasonal changes in biomass.
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Zoology Department, Victoria University of Wellington.
New Zealand has no native land mammals, except for two species of bat. However, the early explorers and settlers brought with them a variety of domestic mammals including pigs, cattle, sheep and goats, to provide food and skins. Some of these animals escaped domestication and returned to the wild state. Also, when European colonisation was established, a demand for game animals was met by a number of mammalian introductions from Europe, England, Australia and America. These introductions continued until 1909 by which time many of the wild mammals had become successfully established.
Thus New Zealand acquired a composite domestic and wild mammal fauna which rapidly expanded its distribution and achieved prime economic significance; the domestic animals as the foundation of an agriculturally- based economy, the wild mammals both as a source of revenue and as pests.
The history and spread of these introductions have been documented by Thomson (1922), Donne (1924), Wodzicki (1950), and de Vos, Manville and Van Gelder (1956).
Beginning in 1961, the author carried out a study of the parasites of red deer (Andrews, 1964) and more recently has examined the following wild ruminants for parasites; chamois (Rupicapra rupicapra L.), tahr (Hemitragus jemlahicus Hamilton-Smith, 1827), goat (Capra hircus L.), sika deer (Cervus nippon mantchuricus Swinhoe, 1864), rusa deer (Cervus timoriensis Blainville, 1822), sambar deer (Cervus unicolor Lydekker, 1913), wapiti (Cervus canadensis Erxleben, 1777), virginia or white tailed deer (Odocoileus virginianus Boddaert, 1875), and fallow deer (Dama dama L.).
Some of the preliminary results of this study have been noted in Christie and Andrews (1964, 1965a, 1965b, 1966) and other results will be published at a later date.
Several of the helminths recorded are species commonly found in domestic animals such as sheep and cattle and may be readily identified with the aid of veterinary tests such as Lapage (1956).
The helminths recorded here are from the alimentary canal lungs, liver and body cavity of the hosts, and the site or sites of infection are given for each species in the key. A number of species may be found in more than one organ, for example, species from the abomasum may sometimes be found in the small intestine and vice versa.
Worms from the alimentary tract may be recovered by placing the contents of each organ in a sieve with a fine mesh (e.g., 0.014 in. aperture) and washing them until the water passing through the sieve runs clear. The residue can then be removed to petri dishes for examination under a low power binocular microscope. Worms from the liver and lungs can be recovered by slitting open the bile ducts and bronchii respectively.
If the worms are alive when they are recovered they can be fixed in formal-acetic-alcohol (trematodes and cestodes) or hot 70% alcohol (nematodes)—see Manter (1951). The worms may be stored in 70% alcohol. Nematodes do not usually require staining but some of the larger specimens may require clearing. This is done by placing the worms in a mixture of four parts of 70% alcohol to two parts of glycerine, concentrating the mixture in a warm (about 46°C) paraffin oven until the alcohol evaporates, and then placing the worms in several changes of glycerine until they become cleared. The specimens can then be mounted in glycerine jelly. Trematodes and cestodes may be stained in aceto-alum-carmine (see Manter, 1951).
To ease interpretation of the key, a short glossary of some of the terms used is provided. This glossary is supplemented by illustrations of some of the diagnostic features of the worms (text fig. 1).
Text figure 1 — Nematode morphology
A. Head region. B. Posterior of male. C. Female reproductive structures. al — anterolateral rib; am — accessory membrane; ar — ribs of accessory membrane; av — anteroventral rib; bc — buccal capsule; cg — cervical groove; cp — cervical papillae; cv — cephalic vesicle; d — dorsal rib; ed — externodorsal rib; g — gubernaculum; gc — genital cone; la — lateral alae; m — mouth; ml — mediolateral rib; o — oesophagus; ob — oesophageal bulb; ov-1, ov-2, ov-3, ovijectors; pb — prebursal palillae; pl — posterolateral rib; pv — posteroventral rib; s — spicules; v — vulva.
It will be seen from the key that, in many cases, emphasis has been placed on the characteristics of the male worms. These characteristics are generally more diagnostic than those of the female, although, where possible, reference has been made to the features of female worms.
Text figure 2 — Helminths Recorded from the Wild Ruminants
A. Haemonchus contortus spicules.
B. Haemonchus contortus male bursa.
C. Oesophagostomum venulosum male bursa and spicules.
D. Cooperia curticei spicules.
E. Cooperia curticei male bursa.
F. Bunostomum trigonocephalum spicules.
G. Bunostomum trigonocephalum male bursa.
H. Nematodirus filicollis male bursa and spicules.
Abbreviations: al — anterolateral rib; av — anteroventral rib; d — dorsal rib; ed — externodorsal rib; ml — mediolateral rib; pl — posterolateral rib; pv posteroventral rib; s — spicules.
Text figure 3 — Helminths Recorded from the Wild Ruminants
A. Trichostrongvlus capricola male bursa and spicules.
B. T. axei male bursa and spicules.
C. T. vitrinus male bursa and spicules.
D. T. colubriformis male bursa and spicules.
Abbreviations: al — anterolateral rib; av — anteroventral rib; d — dorsal rib; ed — externodorsal rib; ml — mediolateral rib; pl — posterolateral rib; pv — posteroventral rib.
female 14 mm to 25 mm in length. Eggs approximately 0.145 mm × 0.075 mm. Found in the small intestine.
Nematodirus filicollis (text fig. 2)
Text figure 4 — Helminths Recorded from the Wild Ruminants
A. Capillaria bovis posterior end of male.
B. Trichuris ovis posterior end of male.
C. Skrjabinema ovis posterior end of male.
D. Skrjabinema ovis 1. En face view of optical section through male oral cavity.
2. En face view of male head.
3. En face view of female head.
E. Taenia hydatigena lateral view of scolex.
F. Dictyocaulus viviparus male bursa and spicules.
G. Fasciola hepatica.
Abbreviations: al — anterolateral rib; at — anterior testes; bm — bursal membrane; c — caeca; cp — caudal palippae; ct — cloacal tube; d — dorsal rib; ed — excretory duct; em — egg mass; edl — externodorsal rib; edt — ejaculatory duct; gp — genital pore; gub — gubernaculum; i — intestine; il — interlabia; l — labia; lm — lateral membrane; mo — mouth; ms — median sucker; os — oral sucker; p — pharynx; pt — posterior testes; ro — rostellum; s — spicule; s — sucker; sg — shell gland; sh — spicule sheath; sp — spicule; t — testis; vd — vas deferens; ve — ventral ribs; yg — yolk glands.
Text figure 5 — Helminths Recorded from Wild Ruminants
A. Skrjabinagia lyrata spicules.
B. S. podjapolskyi spicules.
C. Ostertagia leptospicularis spicules.
D. O. ostertagi spicules.
E. Stadelmannia circumcincta spicules
F. S. trifurcata spicules.
G. Spiculopteragia odocoilei spicules.
H. Apteragia quadrispiculata spicules.
I. Spiculopteragia spiculoptera spicules.
J. S. asymmetrica spicules.
K. Rinadia mathevossiani spicules.
I would like to thank Dr.
Cervus elaphusL.) in New Zealand
Trans. R. Soc. N.Z.5(9): 97-121.
Tuatara, 12(2): 69-77.
Tuatara13(1): 1-8.
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Veterinary Parasitology.Oliver and Boyd, London, 964pp.
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Bull. N.Z. Dept. scient. ind. Res., 98: 250 pp.
Associate Professor of Geology, Victoria University, Wellington.
The Axis of the growing Rimutaka Range reaches the coast of Cook Strait 1 km east of Cape Turakirae. The east flank is steeply dipping and faulted by the Wairarapa Fault. The west flank dips gently for 14 km to the Wellington Fault.
Six uplifted marine beach ridges here named A, B, C, D, E, and F are exceptionally well preserved for 5 km east of the Rimutaka Axis. Beach ridge A has grown since the 1855 Earthquake and is poorly developed: B was growing until elevated during the 1855 Earthquake; C is the largest and is the oldest containing pumice erupted in A.D. 200; D is the next largest; and F, the highest and oldest, is considered to have formed immediately after the post-glacial rise in sea level, and to be about 6,500 years old.
The six uplifted beach ridges dip westward. Ridge F is 25 m above the mean sea level 4 km north-east of Turakirae Head, 23.5 m at the head itself, and 13 m at 4 km north-west of the head. From the right angle in the coast at the head, the direction of tilting is determined as being about 270° and at right angles to the crest of the growing Rimutaka Range. The average rate of tilting of the gentle flank of the anticline is 0.03° per 1,000 years, and the rate of uplift at the anticlinal axis 4m per 1,000 years.
Since there is a complete absence of ridges intermediate between A, B, C, D, E, and F, and because of the sudden uplift that took place during the 1855 Earthquake, the growth of each ridge is thought to have been started and terminated by sudden earthquake uplift. The following uplift sequence is inferred from the size and elevation of the ridges at the anticlinal axis:
F 3 m, (5.6); E 6m, (4.9); D 9m, (3.1); C 6.5m, (0.6); B 2.5m, (0.1); A, successive uplifts being given in metres and time of uplifts in thousands of years ago. Within the sequence the amount of each uplift is closely proportional to the length of time from the previous to the following uplift, and the next uplift of the Rimutaka Axis is expected to take place about 500 years hence.
Fig. 1: Sketch map of S.W. corner of North Island of New Zealand showing position of tilted beach ridges relative to the main active faults and the growing anticlines. The position of the intersection of the beach ridges is known approximately only.
The common intersection of ridges B, C, D, E, and F (but not A and B) on a line between the Rimutaka and Wellington anticlinal axes indicates a long continued balanced uplift of both fold axes. Ridges A and B intersect west of the Wellington Axis, indicating that movement during the 1855 Earthquake was unbalanced and took place on the Rimutaka Axis only. Balance would be restored by uplift of the Wellington Axis only provided that it takes place before Ridge A becomes well developed.
The tilted marine beach ridges of Turakirae Head lie 17 km S.E. of Wellington City in the S.W. corner of the North Island of New Zealand. The region is crossed by two active major faults — the Wellington and the Wairarapa. Both are dextral and both are
The ridges at Turakirae Head are by far the best example of tilted beach ridges in New Zealand and among the best in the world (Fig. 5). There are six beach ridges in all: A, B, C, D, E and F; A being that of the present day and F the highest and oldest. Each old beach ridge is a distinct bank of gravel that slopes inland as well as seaward. The upper ridge is largely covered by screes from the Rimutaka Range but the lower four can be traced continuously for 5 km. The present day beach ridge is poorly developed and cannot be traced continuously. The ridges rest on a platform cut across steeply dipping ‘greywacke’ of Triassic age that is littered with boulders up to 2 m high. The platform and boulders extend seaward for an unknown distance. The boulders are older than the beach ridges and represent the most resistant part of the greywacke that was eroded when the platform was cut. Being one of the few sources of cheap resistent rock near Wellington City, the boulders are now being extracted, the coast is being appreciably changed, and its scientific interest diminished.
Much of the energy of the waves that sweep towards the expose coast is absorbed by the boulders and the seaweed that grows on them, and the beach ridge of the present day is forming at the remarkably low level of about 1 m above M.H.W.M. The tidal range is only 1.1 m. Conditions are thus ideal for recording progressive uplift and tilting of the land.
The height of the beach ridges was determined by levelling along the crest of each beach ridge with an automatic level, levels being taken at points about 100m apart. Irregularities, largely due to the number and size of the boulders, were smoothed out by averaging over each 500 m length, the mean difference between each observation and the average being about 0.3 m. Towards the mouths of the Orongorongo and Wainuiomata Rivers the boulders are buried beneath the flood of gravels from the rivers, the waves are not absorbed, and the ridges were formed 1 m to 2 m higher than where sheltered by the boulders. (See left hand side of Fig. 3).
Fig. 2: Diagram showing heights of past sea levels relative to the present day sea level for localities with uplift rates ranging from 0 to +7 mm per year relative to the Netherlands. Diagram is based on data from the Netherlands, New Zealand, and other localities for which three or more sea level heights that are well distributed in time are known for the last 10,000 years. It should be noted that the lines for the various uplift rates are not independent. If one is known the others can be calculated. The diagram shows that submergence was followed in regions with uplift rates of more than about 2 mm per year (relative to the Netherlands) by emergence. The total emergence given by the emergence height of the Highest Holocene Shoreline (H.H.S.) is used to date the oldest beach ridge. It should be noted that the diagram is not applicable to localities undergoing isostatic or other non-uniform uplift, and that the uplift rate of most parts of the world is about + 1.3 mm per year relative to the Netherlands.
All that can be determined, if a coast line is straight, is the tilt component in the direction of the coast. It is fortunate that there is a right angle bend at Turakirae Head. By using the heights of the ridges around the right angle, the direction of tilt on that part of the coast can be reliably determined. Directions of
Fig. 3 shows the height of the six ridges on the east-west projection plane. The dots represent average heights, and if lines are drawn through the dots and extended to the west it will be found that ridges B, C, D and E (but not A and B) intersect (within the limit of accuracy of the measurements) at a point that lies on the southern extension of the south-east side of Wellington Harbour. The intersection of the lines at a common point indicates that the axis of rotation was fixed, and that successive uplifts have been proportional at all places.
The intersection of ridges A and B as determined by the uplift that took place during the 1855 Earthquake lies 25 km to the N.W. of the intersection of the other ridges. The reason for the difference in position is discussed later.
The absence of material for radio-carbon dating makes it impossible to determine the age of the older beach ridges directly. At Turakirae Head ridge C contains pumice that was erupted in A.D. 200, and at Putangirua Stream 30 km east of Turakirae Head wood from one of the higher of a similar series of beach ridges gave a radio-carbon age of about 4,000 years (Grant-Taylor and Rafter, 1963). It is thus reasonably certain that the oldest of the ridges at Cape Turakirae is more than 4,000 years old. Indirect methods are used to get better age. It is assumed that during the last 10,000 years sea level was at the same ‘height’ at all places in the world. That is to say that its level was not appreciably affected by changes in the rate of rotation of the earth or by changes in the salinity (density) of its water. It is further assumed that during the last 10,000 years the average rate of uplift or submergence has been uniform everywhere outside the regions of isostatic uplift. It is impossible to be sure that any particular region is stable, but relative height changes can be determined provided that the height of sea level is known at corresponding times. In Fig. 2 the height of sea level relative to present sea level is shown for the last 10,000 years for regions that are rising uniformly at rates ranging from 0 to 7 mm per year relative to the Netherlands. The Netherlands is chosen as datum because sea level
three past sea levels are known.
Fig. 3: Cross section plotted on east-west plane showing heights of the six beach ridges at Turakirae Head. Heights are given in metres above approximate M.H.W.M. The vertical lines are the north-south grid lines, the numbered lines being 1,000 yards apart. The mouth of the Orongorongo River is at 453, Turakirae Head at 468, and the axis of the Rimutaka Range at about 495. Beach ridges defined by closely spaced levels are shown by solid lines, those less well defined by dashed lines. The dots are average values for the best defined parts of the ridges and the dotted lines give the best indication of uplift and tilting. By extending the dotted lines it will be seen that ridges B, C, D and E intersect near grid line 400, whereas ridges A and B intersect much further to the west.
The curves have been constructed by assuming that the rate of uplift has been uniform, but in general different, at all localities. All samples not more than a few kilometres apart are considered to belong to a single locality. Height was then plotted against time on a separate sheet of tracing paper for each locality, the height scale and time scale being the same for each locality.
The sheets of tracing paper were then superposed and adjusted to give the best fit for the points representing the radio-carbon-dated past sea levels. For most localities there are two degrees of freedom. One corresponds to the unknown rate of uplift and the other to the unknown height above or below sea level of the dated samples at the time they formed. The uplift rate is allowed for by tilting the sheet of tracing paper, and in order to prevent the tilt from seriously
Fig. 4: Diagram showing stages of ridge formation and uplift near axis of Rimutaka Range. Duration of beach formation is based on relative cross sectional area of ridges and is given an 10 arbitrary units for C, the largest ridge. It will be seen that the points midway along the times representing ridge formation (still-stand) lie on a straight line that gives the average rate of uplift. The amount of each uplift has been proportional to the total time from the previous to the following uplift, and the time of the next uplift is forecast by the dotted lines in the top right hand corner.
When the sheets of paper had been adjusted to produce the ‘best fit’, a line was drawn through the points, extreme values being neglected. The Netherlands, the ‘locality’ with the most points, was used as the datum, and values were then calculated for uplift rates of 1 to 7 mm per year relative to the Netherlands. Provided that the emergence height of the highest Holocene Shoreline (H.H.S.) is known, the curves give the average rate of uplift relative to the Netherlands, and the approximate age of the H.H.S. and indicate that the highest beach ridge at Turakirae Head is about 6.5
Fig. 5: Oblique air photograph of rock platform near Turakirae Head. The four beach ridges are B, C, D, and E. A is poorly defined and is hidden by surf, and F is buried beneath the scree at the foot of the hill at the back. Boulders and rock outcrops up to 3 m high are scattered over the whole width of the platform. Note the absence of any trace of intermediate beach ridges.
As mentioned, the average rate of uplift of the Turakirae coast relative to the Netherlands, or any other place, can be determined by comparing the differences in height between present day sea level and the sea level at any particular time in the past at the two places, and then calculating an average relative rate of uplift for the time interval. In order to determine the true rate of uplift, comparison has to be made with an area that is known to be stable. But no place is known with certainty to be stable and the best that can be done is to assume that the places that are modal with respect to sea level changes are stable, and those non-modal unstable. For the last 50 years mareograph (tide guage) measurements can be used, and it is commonly accepted that sea level has been rising at a rate of 0.8 mm per year for the last 50 years (Jakubovsky, 1966). It is of interest that this is also true for Wellington and Auckland, the two places in New Zealand where we have long-term mareograph records.
In the Netherlands the mareographs are all tied in to Amsterdam which has an unrivalled record that extends back to 1670 A.D. (Waalewijn, 1966.). For the last 50 years sea level has been rising there at the rate of 2.1 mm per year, 1.3 mm per year faster than the modal rate of 0.8 mm per year, and it is thus reasonably certain that the Netherlands is subsiding at 1.3 mm per year. It is more difficult to obtain modal values for earlier sea levels but those available indicate that the Netherlands has been subsiding at about the same rate for at least the last 7,000 years. By making the correction of 1.3, the rate of uplift of the Turakirae coast can be determined from Fig. 2. It is about 4 mm per year on the coast at the axis of the Rimutaka Anticline decreasing almost uniformly to zero at the south-eastern side of Wellington Harbour at the point of intersection of the uplifted beach ridges. Tilt rate is more easily determined than uplift rate, and depends merely on knowing the tilt and the age of a tilted surface. For the Turakirae coast the average rate of tilting for the last 7,000 years is 0.03° per 1,000 years.
In spite of conditions being ideal for their formation and preservation, there is no trace of any shoreline features between the six well defined ridges (Fig. 5). It is inferred that the ridges represent periods of still-stand, and the spaces between the ridges periods of rapid uplift. The last uplift took place during the 1855 Earthquake and was sudden, and it is inferred that the other uplifts took place during earlier earthquakes and were sudden also.
The oldest beach ridge is estimated to have formed about 6,500 years ago and the youngest cannot have started to grow until after the 1855 Earthquake. The relative time of the still-stand for the intermediate beach ridges is estimated from their relative cross sectional area by assuming that their rate of growth was constant at any one part of the coast. As the age of the oldest ridge and the uplift values are known a diagram has been constructed (Fig. 4), showing the amount of each uplift and the duration of each still-stand periods. It will be seen that the mid points of each ‘still-stand’ line lie on a straight line which defines the average rate of uplift at the crest of the Rimutaka Anticline (the part of the coast chosen for illustration). The amount of any one uplift is thus proportional to the total time from the previous to the following uplift and it is estimated that the next uplift will take place in 500 years time and will be at least 1.5 m.
Fig. 6: Marine rock platforms on the spur between the Orongorongo and Wainuiomata Rivers. The Holocene bench is at the bottom right corner. The lowest high level bench is considered to represent the Last Interglacial and to be about 100,000 years old. It is covered by several metres of scree and rises towards the crest of the Rimutaka Range which forms the sky-line of the photograph. There are two higher high level benches. The lower of the two is well defined and the higher on the extreme left hand side of the photograph less well defined. The higher is 250 m above sea level.
The difference in position between the line of intersection of ridges A and B and the common intersection of the older ridges B, C, D, E, and F requires explanation. When projected on to a cross section in the direction of tilt the older beach ridges are almost straight lines and successive uplifts have been proportional at all places. The intersection of ridges A and B being well to the west of the common intersection of the older beach ridges indicates that the uplift that took place in 1855 was not proportional to the earlier uplifts.
The difference can be explained if the uplift that takes place during particular earthquakes is related, for example, to the parallel folds of the south end of the North Island. If folding, as is likely, is a summation of sudden movements, then they must average themselves out in some way to produce the folds. If they were all centred on a single point they would produce, not the parallel anticlines that exist, but a simple dome. It is inferred that the averaging out is done by earthquake uplift taking place first here and then there, and never in the same place until a stage in the uplift of the anticlines of a region is complete. In the long term the anticlines will grow steadily each keeping pace with the other, but the short term uplift during individual earthquakes will be anomalous with respect to the long term uplift pattern.
The apparently anomalous uplift of the 1855 earthquake is thus expected. It will be rectified if uplift takes place on the axis of the Wellington Anticline before Beach Ridge A has become sufficiently well developed to become an obvious beach ridge in the future.
The values given for the uplift rate at the axis of the Rimutaka Range at the coast of 4 mm per year, and the tilt rate for the dip slope of the range of 0.03° per thousand years, appear to be small and have little meaning for geologists until they are expressed in geological time intervals. They then become 4 km per million years and 30° per million years, and it is clear that the deformation cannot have continued for a million years nor can it continue for a million years into the future. It is thus important to know if the deformation that has taken place during the last 7,000 years is merely a short-lived phase with little tectonic importance, or whether it has continued long enough to have tectonic importance. The higher benches on the Turakirae coast provide the answer. High level rock platforms that are analogous to the low level platform on which the beach ridges are situated, are conspicuous coastal features west of the Orongorongo River (King, 1930). The lowest is almost
In modifying my original account of the Turakirae beach ridges I have been guided by suggestions made by the Ph.D. Students of the Geology Department of Victoria University. I wish to thank them for their help and interest.
Radiocarbon, Vol. 5, p. 122 (N.Z.-24).
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