Montane Zone Research Articles

The influence of physical soil conditions on the formation of root nodules of Melilotus officinalis in the montane zone of Rocky Mountain National Park

Exotic invasion is a key threat to native biological diversity, second only to habitat degradation. Melilotus officinalis is an exotic species that thrives in areas of anthropogenic disturbances and low nutrient availability. Typically, natural disturbance facilitates native species establishment and maintains species diversity; however, anthropogenic disturbance facilitates exotic species establishment. M. officinalis functions as a competitor in the montane communities because of its symbiosis with Rhizobium bacteria, a symbiosis that allows the plant to acquire nitrogen. Although the ability to fix nitrogen permits M. officinalis to grow in nitrogen depleted soils, the soil must have a microclimate that is favorable to symbiosis and nodulation. We analyzed abiotic soil characteristics in Rocky Mountain National Park to determine if nodulation was related to soil texture, as well as in the mid-range level of soil and temperatures. We found that nodules on plant specimens showed a positive correlation with soil moisture and temperature, and occurred in a specific range of moderate moisture and temperature. Soil texture was not correlated to nodule formation.

The genus Acytostelium

Members of the genus Acytostelium are the smallest Dictyostelids, characterized by slender acellular sorophores which support very small globose to subglobose sori. Seven species are presented as new; all were isolated since 1990, and all but one from ecologically diverse tropical environments. They are: A. digitatum, from semievergreen rain forest at Tikal, Guatemala; A. aggregatum and A. amazonicum, from tropical rain forest of the Peruvian Amazon; A. pendulum, from a Mayan milpa in Southern Belize; the largest, A. magnuphorum, from a bog in North Central Ohio; A. reticulatum, from the lower montane zone of the Loquillo Experimental Forest, Puerto Rico, and the smallest, A. minutissimum, from elfin woodland on the rim of Volcan Cacao in Costa Rica.

Cono‐ and seminiphagous insects of Norway spruce Picea abies (L.) Karst. and their parasitoids in lower and upper montane zone of the Tatra National Park in Poland

Abstract: A study of the insects inhabiting of cones of Norway spruce Picea abies (L.) Karst. in the Tatra National Park was conducted during 1987–92. As a result of breeding and analyses of the cones collected from trees at various altitudes above sea level, 53 746 specimens of cono‐ and seminiphagous insects were collected. Interior damage to cones and the losses of spruce seeds caused by pests were measured, with regard both to the variable cone crop abundance of spruce and to different altitudes above sea level. The role of parasitoids in limiting the numbers of some cono‐ and seminiphagous insects was also estimated.

The Genus Acytostelium

Members of the genus Acytostelium are the smallest Dictyostelids, characterized by slender acellular sorophores which support very small globose to subglobose sori. Seven species are presented as new; all were isolated since 1990, and all but one from ecologically diverse tropical environments. They are: A. digitatum, from semievergreen rain forest at Tikal, Guatemala; A. aggregatum and A. amazonicum, from tropical rain forest of the Peruvian Amazon; A. pendulum, from a Mayan milpa in Southern Belize; the largest, A. magnuphorum, from a bog in North Central Ohio; A. reticulatum, from the lower montane zone of the Loquillo Experimental Forest, Puerto Rico, and the smallest, A. minutissimum, from elfin woodland on the rim of Volcan Cacao in Costa Rica.

Vertebrate Responses to Spatiotemporal Variation in Seed Production of Mast-Fruiting Dipterocarpaceae

To examine the interspecific reproductive synchrony of Dipterocarpaceae with vertebrate responses to seed availablity, we monitored the spatiotemporal distribution and phenology of more than 2367 adult dipterocarp individuals of 54 species from March 1985 to January 1993 in the Gunung Palung National Park, West Kalimantan, Indonesia. Seven vegetational formations were sampled along an altitudinal gradient from peat swamp forest (5 m a.s.l. [above sea level]) across lowlands to upper montane zones (1100 m a.s.l.) that encompassed two upland valley complexes in a 15-km2 area. Four significant reproductive events were documented: (1) a common lowland species reproduced outside of mast events in 1986 and in 1990; (2) a localized lowland “minor” mast event in 1986 in which 24.3% of the adult trees (21 spp.) participated; (3) a major community-wide mast event (92.8%, 48 spp.) in 1987, just 6 mo after the minor event; and (4) another major community-wide mast fruiting event after a 4-yr intermast interval (88%, 48 spp.) in 1991. West Kalimantan export records of illipe nut (Dipterocarpaceae: Shorea section Pachycarpae) from 1968 to 1997 were compiled as a baseline measure of the frequency and relative intensity of dipterocarp mast-fruiting events in the region (cv = 152%). A “bumper crop” occurred about every 5 ± 2.6 yr (mean ± 1 sd; range 3–9 yr). Fruit production was significantly associated with El Niño–Southern Oscillation (ENSO) events. The 1987 and 1991 mast events monitored were the third and fourth largest export years in the province since 1968. Because of the disputed role of vertebrate seed predators in causing and maintaining mast-fruiting behavior, the response of seed-eating vertebrates to this spatiotemporal variation in dipterocarp seed production was examined. Seed of a common, but asynchronous, lowland species was largely consumed by vertebrates. In the 1986 minor mast, 21 dipterocarp species that produced 60 000 seeds/ha (dry mass 46 kg/ha) lost all monitored viable seed to a diversity of resident and nomadic vertebrate seed predators. Timed with dipterocarp seed production in all mast events, nomadic vertebrates increased their populations through both reproduction and regional movement (numerical response). However, in both the 1987 and 1991 mast events, resident vertebrates destroyed only 1.5% and 2.6% of community seed production, and predation was recorded only in the tails of the fruit-fall distribution. During these community mast events, resident vertebrates switched from dipterocarp seed to feed on fruit and seed from other available species. Nomadic vertebrates arrived late in the fruit-fall period during both major mast events and, thus, were able to destroy only seed dispersed in the final 1–3 wk of fruit-fall. Seed escape, and thus regeneration, only occurred in major mast events when all dipterocarp species across large areas participated. Considerable seedling recruitment was recorded in both the 1987 (∼95 000 seedlings/ha) and 1991 (155 824 ± 36 764 seedlings/ha) mast events. Results from this natural experiment indicate that resident and nomadic vertebrates cause stabilizing selection for tight interspecific synchrony of dipterocarp seedfall over vast regions. Although the pattern generally conformed to the predator-satiation hypothesis, the observed mechanisms for seed escape within a mast-fruiting event did not. Resident and nomadic vertebrate foraging and ranging patterns resulted in dipterocarp seed “escape” rather than local “swamping” with copious seed production per se. To account for these observations, two hypotheses, “interfamilial satiation” and “regional escape,” were developed. The period of seed availability and length of the regional intermast interval is examined with seed-predator reproduction and behavior to assess the impact of seed availability on seed-predator populations. The importance of rare events and appropriate spatial scale for investigating evolutionary and ecological processes such as mast fruiting are addressed.

VERTEBRATE RESPONSES TO SPATIOTEMPORAL VARIATION IN SEED PRODUCTION OF MAST-FRUITING DIPTEROCARPACEAE

To examine the interspecific reproductive synchrony of Dipterocarpaceae with vertebrate responses to seed availablity, we monitored the spatiotemporal distribution and phenology of more than 2367 adult dipterocarp individuals of 54 species from March 1985 to January 1993 in the Gunung Palung National Park, West Kalimantan, Indonesia. Seven vegetational formations were sampled along an altitudinal gradient from peat swamp forest (5 m a.s.l. (above sea level)) across lowlands to upper montane zones (1100 m a.s.l.) that encompassed two upland valley complexes in a 15-km 2 area. Four significant reproductive events were documented: (1) a common lowland species reproduced outside of mast events in 1986 and in 1990; (2) a localized lowland ''minor'' mast event in 1986 in which 24.3% of the adult trees (21 spp.) participated; (3) a major community-wide mast event (92.8%, 48 spp.) in 1987, just 6 mo after the minor event; and (4) another major community-wide mast fruiting event after a 4-yr intermast interval (88%, 48 spp.) in 1991. West Kalimantan export records of illipe nut (Dipterocarpaceae: Shorea section Pachycarpae) from 1968 to 1997 were compiled as a baseline measure of the frequency and relative intensity of dipterocarp mast-fruiting events in the region ( CV 5 152%). A ''bumper crop'' occurred about every 5 6 2.6 yr (mean 6 1 SD; range 3-9 yr). Fruit production was significantly associated with El Nino-Southern Oscillation (ENSO) events. The 1987 and 1991 mast events monitored were the third and fourth largest export years in the province since 1968. Because of the disputed role of vertebrate seed predators in causing and maintaining mast-fruiting behavior, the response of seed-eating vertebrates to this spatiotemporal variation in dipterocarp seed production was examined. Seed of a common, but asynchronous, lowland species was largely consumed by vertebrates. In the 1986 minor mast, 21 dipterocarp species that produced 60 000 seeds/ha (dry mass 46 kg/ha) lost all monitored viable seed to a diversity of resident and nomadic vertebrate seed predators. Timed with dipterocarp seed production in all mast events, nomadic vertebrates increased their pop- ulations through both reproduction and regional movement (numerical response). However, in both the 1987 and 1991 mast events, resident vertebrates destroyed only 1.5% and 2.6% of community seed production, and predation was recorded only in the tails of the fruit-fall distribution. During these community mast events, resident vertebrates switched from dipterocarp seed to feed on fruit and seed from other available species. Nomadic vertebrates arrived late in the fruit-fall period during both major mast events and, thus, were able to destroy only seed dispersed in the final 1-3 wk of fruit-fall. Seed escape, and thus regeneration, only occurred in major mast events when all dipterocarp species across large areas participated. Considerable seedling recruitment was recorded in both the 1987 ( ;95 000 seedlings/ha) and 1991 (155 824 6 36 764 seedlings/ha) mast events. Results from this natural experiment indicate that resident and nomadic vertebrates cause stabilizing selection for tight interspecific synchrony of dipterocarp seedfall over vast regions. Although the pattern generally conformed to the predator-satiation hypothesis, the observed mechanisms for seed escape within a mast-fruiting event did not. Resident and nomadic vertebrate foraging and ranging patterns resulted in dipterocarp seed ''escape'' rather than local ''swamping'' with copious seed production per se. To account for these observations, two hypotheses, ''interfamilial satiation'' and ''regional escape,'' were developed. The period of seed availability and length of the regional intermast interval is examined with seed-predator reproduction and behavior to assess the impact of seed availability on seed-predator populations. The importance of rare events and appropriate spatial scale for investigating evolutionary

Nitrogen mineralization and nitrification following land conversion in montane Ecuador

The lower montane zone of northwestern Ecuador, like many parts of the tropics, is undergoing rapid conversion from native forest vegetation to crop and pastureland. The current landscape is a mosaic of agricultural land, forest fragments and second-growth vegetation in various stages of development. While there is abundant research documenting the effects of land-use change in the lowland tropics, such information is scarce for montane regions on young volcanic soils. We compared foxtail pasture ( Setaria sphacelata, [(Schumach.) Stapf and C.E. Hubb.]) and traditional, mixed-species pasture with undisturbed old-growth forest, 15–20 y-old secondary forest and 5–10 y-old shrubby regrowth. At two replicates of each vegetation class, we measured soil nitrogen and carbon pools, in situ net nitrogen mineralization and nitrification, soil respiration and soil physical properties. Setaria pasture decreased soil NO − 3-N pools and net mineralization and nitrification rates compared to mature forest, secondary vegetation, and mixed-species pasture. Soil NO − 3-N in Setaria pastures, during wet and dry seasons, was 40 and 25% of amounts measured in other vegetation types. Net nitrification rates were also lower beneath Setaria during both seasons, the greatest difference occurring during the wet season. Net nitrification rates increased considerably (two-fold and greater) under wet season conditions beneath all vegetation types except Setaria pasture. Soils beneath both pasture types were wetter and had higher bulk density than mature and second-growth forests. Conversion to pasture produces widely varying effects on soil N dynamics depending on characteristics of the pasture species, such as Setaria’s extremely dense root system. Reduced soil N availability beneath Setaria pasture will affect both long-term pasture productivity and subsequent forest regeneration in abandoned pastures.

Mycobiota in symptomless needles of Pinus mugo ssp. uncinata

Healthy-looking needles were randomly collected from Pinus mugo ssp. uncinata at two sites in the montane zone with different edaphic and microclimatic conditions and examined for the diversity of endophytic fungi. One site is on a mountain ridge, the other in a peat bog. On average, about 35–40% of the needles were colonized at both sites. Eleven species of fungi were isolated. Cenangium ferruginosum and Cyclaneusma minus dominated the endophytic mycobiota of the tree stand along the mountain ridge. C. ferruginosum and Lophodermium pinastri were the dominant species in the needles of the trees in the peat bog. C. ferruginosum and L. pinastri occurred mainly in the needle tip; C. minus occurred most frequently in the middle segment of the needles. The needle base was rarely colonized by these fungi. Endophyte colonization of trees along the mountain ridge increased significantly from the uppermost trees to the ones further down the ridge. No clear pattern of colonization was observed for trees in the peat bog except for the colonisation by L. pinastri , which showed a tendency to form infection centres. Species composition was constant within sites, but the frequency of colonization by C. minus and L. pinastri varied greatly among trees.

ORIGIN OF A PARK–FOREST VEGETATION MOSAIC IN THE WIND RIVER RANGE, WYOMING

The vegetation of the montane and subalpine zones of the Rocky Mountains is a mosaic of conifer forests and large (1 ha to several square kilometers) treeless “parks” dominated by sagebrush (Artemisia spp.), grasses, and forbs. Three hypotheses for the origin of parks are proposed. The “permanent site hypothesis” states that the park–forest vegetation mosaic is a result of differences in physical characteristics of sites. In the “remnant hypothesis” parks are thought to be remnants of vegetation that was widespread under previous climate conditions. The “replacement hypothesis” states that parks replace forest vegetation in response to disturbance, climate change, or a combination of these two factors. Patterns in the past distribution of park and forest vegetation in the vicinity of Fish Creek Park (elevation 2750 m) were used to test these hypotheses. Fossil pollen extracted from the sediments of five small ponds in and around Fish Creek Park was used to reconstruct Holocene vegetation changes. Changes in vegetation were reconstructed through the use of multivariate analyses and pollen ratios derived from modern surface samples and by comparison with pollen data from other studies. The pollen record indicates that shortly after deglaciation (∼11000 yr BP) the area supported alpine tundra, followed by whitebark pine–spruce–fir parkland at ∼9500 yr BP. From ∼8500 to 6000 yr BP, a pine parkland occupied the area, perhaps in response to climate conditions warmer than today. By 5000 yr BP a mixed pine–spruce–fir forest resembling the modern subalpine forest near Fish Creek Park probably replaced the pine parkland at all five sites. The modern park vegetation originated only within the last ∼2500 yr. The conversion to park vegetation may not have been synchronous at all three sites, and the replacement of forest by park did not always result in a long-term conversion to park vegetation. The timing and pattern of changes in the vegetation mosaic eliminate the permanent site and remnant hypotheses and suggest instead that climatic cooling over the last several thousand years, possibly combined with removal of forest cover by fire or some other disturbance, could explain the origin of Fish Creek Park.

Temporal and altitudinal variations in the attached algae of mountain streams in Colorado

Attached algae were examined from eight sites in Central Colorado streams (five sites on St. Vrain Creek and three on the Snake River) between June and November, 1995. The sites ranged in elevation from 1600 m to 3500 m a.s.l.(plains zone to alpine zone). Seasonal variation in algal communities were qualified in forms of species composition and abundance (cell counts and biovolumes). The Ochiai coefficient of similarity was used to estimate degree of similarity between communities at different times, on different streams, and at different locations on the same stream. The composition of communities across streams for alpine and foothills zones was very close, but montane communities differed greatly across streams (similarity < 0.1). Temporal variability of attached algae was almost absent in the alpine zone, but was high in other zones. The composition of the alpine community in August developed downstream with a temporal shift: October in the montane and foothills zones, November in the plains zone.

Reversing borealization as a means to restore biodiversity in Central-European mountain forests - An example from the Krkonose mountains, Czech Republic

Forestry in the Central-European mountains is confronted with a severe forest decline, which is attributed to the combined effects of 'borealization', brought about by large scale continued spruce (mainly Picea abies) monocultures, and atmospheric deposition. Borealization is defined as enhanced soil acidification and litter accumulation, retarded nutrient cycling and changed forest climate in such planted coniferous forest ecosystems. An additional effect of borealization is a major decline in biodiversity of the stands. Based on a comparative study of Norway spruce and European beech stands in the Krkonose National Park (Czech Republic), it is concluded that traditional management should be abandoned and that management should instead focus on regeneration towards broad-leaved or mixed forest stands, to enhance the stability of forest ecosystems and their biodiversity, and to reverse borealization in lower montane zones. Available surveys of forest typology were evaluated for their suitability in regeneration management and were found to be unsuitable, since they reflect the effects of borealization rather than true site conditions. The two main pioneer tree species, birch (Betula pendula) and mountain ash (Sorbus aucuparia), were found to improve soil conditions and reverse borealization. Furthermore, trends in natural vegetation and soil development in declined forests and clear-cuts, and their relevance for forest restoration management were studied, focusing on borealization and plant species diversity. It is concluded that this natural development offers very good possibilities for a more passive, low-cost restoration management.

Late holocene environmental change in an upper Montane area of the snowy mountains, New South Wales

This study examines environmental change in the upper montane zone of the Australian Eastern Highlands during the late Holocene, by analysing vegetation, fire and erosion records contained within a small fen located in a frost hollow. Differences in environmental parameters across the prehistoric—historic boundary were particularly investigated in an attempt to characterise better the changes associated with the imposition of European land‐use practices. Decreases in arboreal pollen and an increased charcoal concentration near the base of the analysed sequence, interpreted to be about 1600 y BP until about 1300 y BP, are suggestive of reduced moisture availability. After this, a period of relative stability continued to the close of the prehistoric period. The arrival of Europeans in the region triggered changes in the sediment record, including an increase in the accumulation of sediment by an order of magnitude, and changes in the surrounding vegetation. Saturated isothermal remnant magnetism (SIRM) was found to be significantly higher in the historic period compared to the analysed prehistoric period, suggesting an alteration in the erosional processes within the catchment. The concentration of charcoal was comparable between the prehistoric and historic periods; however, the increased sedimentation rate of the historic period infers an increased accumulation of charcoal. Fire did not appear to be related to the vegetation changes evident in the historic period, perhaps due to the use of cool fires by the pastoralists.

The phytogeography of Scotland

Summary The phytogeography of Scotland is discussed in relation to a new phytogeographical classification of British and Irish vascular plants. The flora is dominated by species in the Temperate and Boreo-temperate major biome classes; the Southern-temperate species form the third largest group. The northern classes (Arctic-montane, Boreo-arctic Montane, Wide-boreal and Boreal-montane) in Britain and Ireland include relatively few species, but are particularly well represented in Scotland; species in the Mediterranean elements are not well represented. Species with Oceanic affinities occur throughout Scotland, but are most numerous in the west and south-west; the absence of a large, nationally or inter-nationally significant group of Oceanic plants in the highly oceanic areas of north-west Scotland is remarkable. A classification of Scotland into three phytogeographical zones based on the major biome categories identifies a montane zone where the northerly species are concentrated and a lowland zone with temperate and southerly species; the inter- mediate zone is lacking in both extremes and even the more wide-ranging species are under-represented.

Eriocaulon schimperi (Eriocaulaceae) and Some Related Species in Eastern Africa

Eriocaulon schimperi K6rn. is one of the most robust and conspicuous species of Eriocaulon in Africa, forming rosette-like clumps of thick, broad leaves at the apex of a tough rootstock or short rhizome. Several stout scapes up to 35 cm or more high arise from the rosette, each topped by a white or greyish-white capitulum about 10-15 mm wide. It is confined to the montane zone of eastern Africa from Ethiopia to N Malawi at altitudes between 2000 and 3000 m, where it occurs in marshy grassland, along streamsides and in peat bogs with sphagnum moss and sedges. E. schimperi is very variable, and in common with many other afromontane species, populations in different mountain areas sometimes appear very different in facies. This variation in facies arises mainly from differences in vigour of the plant and in the form and colour of the involucral and floral bracts. An examination of the material at

Hypotrachyna taylorensis (Parmeliaceae) a European Species in the New World

Hypotrachyna taylorensis (Mitch.) Hale and H. rockii (Zahlbr.) Hale are morpholog- ically similar species with identical secondary substances, but so far as known these species have different distributions. Several thalli of H. taylorensis have been found in collections originally identified as H. rockii from North, Central, and South America. The lichen called H. rockii actually includes two species, one corresponding to H. rockii sensu stricto and the other to H. taylorensis. Hypotrachyna taylorensis usually has coarsely granular to schizidiate soredia developed on pus- tules and wrinkles, whereas the soralia of H. rockii are mainly subapical, subcapitate, and gran- ular to farinose. Hypotrachyna taylorensis (Mitch.) Hale has so far been regarded as a European species, where it is an element of the oceanic and, more rarely, sub- oceanic lichen flora growing on bark and rock in the western atlantic countries. In central Europe, it seems to be restricted to bark in humid montane zones, especially those of the Alps. During our re- search on the Swiss Hypotrachyna species, K. Am- mann (in litt.) suggested searching for H. rockii (Zahlbr.) Hale, a widespread species resembling H. taylorensis, with the same chemistry (atranorin, ev- ernic, and lecanoric acids), but currently not known from Europe. We have studied and compared the type specimens of H. rockii (w) and of H. taylor- ensis (BM), 120 specimens named H. rockii from the American continent and the West Indies (us), and about 40 specimens of H. taylorensis collected in Switzerland (BERN, G, Z, ZT and private herbaria).

Scientific results of the BRYOTROP expedition to Zaire and Rwanda 7. Life strategies of epiphytic bryophytes from tropical lowland and montane forests, ericaceous woodlands and the Dendrosenecio subpáramo of the eastern Congo basin and the adjacent mountains (Parc National de Kahuzi-Biega/Zaire, Forêt de Nyungwe/Rwanda)

Life strategies of epiphytic bryophytes are studied along an altitudinal gradient from the eastern Congo basin (tropical lowland zone) to the mountains of the East-African graben (tropical subalpine/alpine Zone; BRYOTROP III-transect). Three strategies, Colonists, Perennial shuttle species and Perennial stayers can be observed, which are further subdivided according to their reproduction tactic (high sexual reproductive effort, high asexual reproductive effort, moderately or low sexual and asexual reproductive effort). Of these, only taxa with a long life span (perennials) are of importance, indicating the unchanging and constant ecological conditions and long-lasting microsites, provided by the epiphytic habitats. The basis for the life strategy pattern analysis along the altitudinal gradient were plant sociological investigations and the determination of the mean percentage cover values for the different life strategy categories. By this, the distribution and occurrence of the different strategies within the communities and the altitudinal zones can be shown. Typical for the epiphytes of the primary rain-forests of the tropical lowland and lower montane zone are Perennial shuttle species and Perennial stayers with moderately or low sexual and asexual reproductive effort. This strategy obviously is favoured by the well balanced, high temperature and humidity regime of these zones and typical of most of the liverworts, dominating the epiphytic communities. They are replaced in the montane rain-forests and cloudy moss forests of the upper tropical montane zone by Perennial shuttle species with high asexual reproductive effort, regenerating mainly by propagules and clonal growth. Within the secondary woodlands of this zone and the unique ericaceous woodlands and subpáramo of the African volcanos, Perennial shuttle species and Perennial stayers with high sexual reproductive effort reach a maximum, building regularly sporophytes under the already xeric and strong diurnal climatic conditions of the subalpine/alpine zone. This reproduction strategy is typical of epiphytic communities of xerophytic woodlands. The frequent change within the life strategy spectra of the different altitudinal zones indicates, that life strategies can be seen as a set of co-evolved adaptive traits, which grow and evolve within different taxa under similar ecological conditions.

&lt;p&gt;&lt;strong&gt;Wissenschaftliche Ergebnisse der BRYOTROP-Expedition nach Zaire und Rwanda 6. Lebensformen und Adaptionen zur Wasserleitung und Wasserspeicherung in epiphytischen Moosgesellschaften im östlichen Kongobecken und den angrenzenden Gebirgsstöcken (Parc National de Kahuzi-Biega/Zaire, Forêt de Nyungwe/ Rwanda)&lt;/strong&gt;&lt;/p&gt;

Life forms, water conducting and water storing structures of epiphytic bryophytes are studied along an altitudinal gradient from the eastern Congo basin (tropical lowand zone) to the mountains of the East-African graben (tropical subalpine/alpine zone; BRYOTROP III-transect). Based on a phytosociological analysis, these adaptations were put in relation to the distribution pattern of the bryophyte communities, as well as to the ecological gradient. The interpretation is based on the mean percent cover of each group. The tropical lowland zone is dominated by the life form mat, which is distinctly correlated with watersacs and taxa of the Jubulaceae, Lejeuneaceae and Radulaceae. In the following perhumid montane zone a clear alteration concerning the life form and the adaptations can be observed. The physiognomy of the primary rain-forests now is dominated by fan-forming Plagiochila species which are standing off the phorophyte by its flattened shoots. They are able to condensate water vapour from the fogs as well as using the low light intensities. Within the epiphytes of the bamboo zone of the upper montane zone, similar adaptation strategies to those of the lowland zone can be observed. The communities of the anthropogeneous montane woodlands of this zone, which are rich in mosses, show an ecomorphological wide spectrum [weft and tall-turfs correlated with a central strand (hadrome), hyalocysts and rhizoids]. Within the tropical subalpine/alpine zone exposed to great diurnal variations of climate, mat, weft and cushion-forming tall-turfs dominate, indicating the more xeric conditions (drought stress) by 88 water storing structures (alar cells, central strand, hyalocysts, rhizoids). In this zone, also structures reach a high mean percent cover, which enables the condensation of water vapour from the fog and mist rising from the upper montane zone or which show a groove-like arrangement of the leaflets. This may be recognized as a mechanism enabling a permanent water supply as well as a drain off of surplus water.

Influence of radiata pine seedlings on chemical properties of some New Zealand montane grassland soils

Radiata pine (Pinus radiata) and cocksfoot grass (Dactylis glomerata) were grown in small pots containing grassland soils collected from seven sites in the South Island montane zone. After one year the overall mean dry matter yield of pine exceeded that of grass by a factor of 2.6, and uptake of all nutrients by pine was substantially greater. Mean soil pH was 0.3 units lower after pine growth than after grass. Organic carbon (C), total nitrogen (N), and organic phosphorus (P) levels were 15–19% lower after pine, while total P was 7% lower. Despite greater nutrient uptake by pine, mean mineralisable N and sulphate sulphur (S) levels in the soil were 500% and 200% higher respectively after pine growth than after grass. Inorganic and Bray-2 P levels were 10% and 20% higher respectively. Grass obtained almost all of its P from the inorganic pool, while pine obtained P from both inorganic and organic pools, though mostly from the latter. It is concluded that the differences observed in C, N, and P concentrations in soil indicate higher rates of mineralisation of soil organic matter in the presence of radiata pine than in the presence of cocksfoot grass. Possible implications for pastoral hill land use in New Zealand are discussed. It is suggested that pines incorporated into farming systems either on a rotational basis, or in wide-spaced agroforestry regimes, may be able to increase the rate of mineralisation of organic P, and also of N and S, and increase their availability to pasture species.

Roads and the Environmental Degradation of Tropical Montane Forests

Roads are often a causal agent in the degradation of tropical forests; in this paper their impact is discussed for the forested, humid montane zone. Because of their steep slopes and high elevations, these forests have disturbance regimes associated with slope instability, limited resilience, and numerous species that are elevational specialists, restricted to narrow altitudinal belts. Roads often augment slope instability and fragment ranges of specialized species. Roads can allow uncontrolled extraction of natural products and landscape conversion. Improvements are needed in the design, construction, and maintenance of these roads. Also needed are studies and mitigation efforts to reduce their effects on the specialized biota of montane forests.

TAXONOMY, VARIATION, AND ZOOGEOGRAPHY OF TENTHREDO MAXIMA (NORTON) (HYMENOPTERA: TENTHREDINIDAE)

AbstractTenthredo retura Ross is here placed in synonymy under T. maxima (Norton) as the subspecies T. maxima retura Ross (syn.nov., stat.nov.). The range of T. maxima is associated with montane meadows or semi-open forest habitats in the montane zone of the Rockies, the Cascades, and the Sierra Nevada. Following the analysis of 24 characters from 2405 specimens, we recognized 12 geographically distinct populations, clustered into two subspecies, T. m. maxima and T. m. retura. Originally included in the originalis group of the genus Tenthredo, T. maxima is characterized as a group of its own with no close relatives in North America. We describe the species and its subspecies, give their distribution, discuss their geographical variation, and attempt to reconstruct their zoogeographical history during the Pleistocene.