Montane Forest Zone Research Articles

Human and climate impact on 15N natural abundance of plants and soils in high-mountain ecosystems: a short review and two examples from the Eastern Pamirs and Mt. Kilimanjaro

Population pressure increasingly endangers high-mountain ecosystems such as the pastures in the Eastern Pamirs and the mountain forests on Mt. Kilimanjaro. At the same time, these ecosystems constitute the economic basis for millions of people living there. In our study, we, therefore, aimed at characterising the land-use effects on soil degradation and N-cycling by determining the natural abundance of 15N. A short review displays that δ15N of plant–soil systems may often serve as an integrated indicator of N-cycles with more positive δ15N values pointing towards N-losses. Results for the high-mountain pastures in the Eastern Pamirs show that intensively grazed pastures are significantly enriched in 15N compared to the less-exploited pastures by 3.5 ‰, on average. This can be attributed to soil organic matter degradation, volatile nitrogen losses, nitrogen leaching and a general opening of the N-cycle. Similarly, the intensively degraded savanna soils, the cultivated soils and the soils under disturbed forests on the foothill of Mt. Kilimanjaro reveal very positive δ15N values around 6.5 ‰. In contrast, the undisturbed forest soils in the montane zone are more depleted in 15N, indicating that here the N-cycle is relatively closed. However, significantly higher δ15N values characterise the upper montane forest zone at the transition to the subalpine zone. We suggest that this reflects N-losses by the recently monitored and climate change and antropogenically induced increasing fire frequency pushing the upper montane rainforest boundary rapidly downhill. Overall, we conclude that the analysis of the 15N natural abundance in high-mountain ecosystems is a purposeful tool for detecting land-use- or climate change-induced soil degradation and N-cycle opening.

Late Quaternary soil genesis and vegetation history on the northern slopes of Mt. Kilimanjaro, East Africa

This study presents numerical dating and geochemical results obtained for a soil transect on the northern slopes of Mt. Kilimanjaro, East Africa. Accordingly, the investigated soils in the montane forest zone comprise Late Quaternary palaeosol-sequences, which are characterised by inverted weathering profiles. This can be explained through the aeolian accumulation of unweathered volcanic dust that is provided by katabatic winds from uncovered periglacial hillsides since at least 28 ka cal. BP. Several proxies (C/N, δ 13C, δ 15N and alkane biomarkers) provide evidence for vegetation changes during the Late Quaternary. Strikingly, an expansion of savannah or alpine C4 grasses as on nearby Mt. Kenya cannot be confirmed. However, C3 grasses expanded remarkably at 2600 m a.s.l. during the last glacial maximum and montane forest communities replaced the ericaceous/grassy communities during the Early Holocene.

Quantifying the fire regime distributions for severity in Yosemite National Park, California, USA

This paper quantifies current fire severity distributions for 19 different fire-regime types in Yosemite National Park, California, USA. Landsat Thematic Mapper remote sensing data are used to map burn severity for 99 fires (cumulatively over 97 000 ha) that burned in Yosemite over a 20-year period. These maps are used to quantify the frequency distributions of fire severity by fire-regime type. A classification is created for the resultant distributions and they are discussed within the context of four vegetation zones: the foothill shrub and woodland zone; the lower montane forest zone; the upper montane forest zone and the subalpine forest zone. The severity distributions can form a building block from which to discuss current fire regimes across the Sierra Nevada in California. This work establishes a framework for comparing the effects of current fires on our landscapes with our notions of how fires historically burned, and how current fire severity distributions differ from our desired future conditions. As this process is refined, a new set of information will be available to researchers and land managers to help understand how fire regimes have changed from the past and how we might attempt to manage them in the future.

Annual dynamics of natural regeneration of silver birch (Betula pendula Roth) on a research plot located in the area of forest decline in the Silesian Beskid Mountains

The study shows a high dynamics approximately five-year-old natural regeneration of silver birch (Betula pendula Roth) growing on the research plot located in the fertile mountain habitat in the middle of the lower montane forest zone in the Silesian Beskid Mountains (Beskid Śląski) compared to its co-occurring species. The dynamics is expressed as a significant annual increment in height and diameter of birch trees, leading in consequence to the appearance of an older sapling phase for most regenerations of this species. This creates the possibility of early undercanopy planting of tree species adjusted to the site conditions, mainly silver fir (Abies alba Mill.) and European beech (Fagus sylvatica L.).

Feasibility of a combined sampling approach for studying caterpillar assemblages - a case study from shrubs in the Andean montane forest zone

Feasibility of a combined sampling approach for studying caterpillar assemblages - a case study from shrubs in the Andean montane forest zone

Temporal Dynamics of Rich Moth Ensembles in the Montane Forest Zone in Southern Ecuador1

ABSTRACTWe studied temporal dynamics of diverse moth ensembles (Arctiidae and Geometridae) in early and late succession stages of forest recovery in the montane zone of southern Ecuador. Moths were sampled using weak light sources (2 × 15 W tubes per trap) during three sampling periods (March–April 2002, wet season; October–November 2002, and August–October 2003, both “dry” seasons). Arctiid moth abundance hardly varied between sampling periods. Estimates of local diversity were lower in 2002 (wet and dry season) than in the dry season 2003, and ensemble composition was more strongly affected by sampling period rather than habitat differences. Geometridae ensembles revealed stronger temporal patterns. Geometrid abundance increased about twofold from the wet to the dry season, and temporal effects on species composition were far more pronounced that in arctiids. These differences might hint to variation in the dependence of geometrid versus arctiid larvae on ephemeral plant resources. Despite these significant temporal dynamics, in both families only a few of the more common species analyzed individually showed strong temporal changes in abundance. Almost all common species occurred as adults during all sampling periods. Therefore, even though temporal dynamics of moth ensembles are not negligible, both moth families are suitable “indicators” of community diversity and change along the succession gradient. Samples must be large enough, however, and preferably should be collated over various times of the year and in parallel, to allow for valid statements about moth diversity and species compositions in relation to habitat differences. These recommendations undermine the validity of the concept of “rapid biodiversity inventories” for speciose tropical insect communities.

Are Wildfire Mitigation and Restoration of Historic Forest Structure Compatible? A Spatial Modeling Assessment

In response to catastrophic wildfires, wide-reaching forest management policies have been enacted in recent years, most notably the Healthy Forests Restoration Act of 2003. A key premise underlying these policies is that fire suppression has resulted in denser forests than were present historically in some western forest types. Therefore, although reducing the threat of wildfire is the primary goal, forest managers commonly view fuel treatments as a means to restore historic forest structure in those forest types that are outside of their historic range of variation. This study evaluates where both wildfire mitigation and restoration of historic forest structure are potentially needed in the ponderosa pine–dominated montane forest zone of Boulder County, Colorado. Two spatial models were overlain: a model of potential fireline intensity and a model of historic fire frequency. The overlay was then aggregated by land management classes. Contrary to current assumptions, results of this study indicate that both wildfire mitigation and restoration of historic forest structure are needed in only a small part of the study area, primarily at low elevations. Furthermore, little of this land is located on Forest Service land where most of the current thinning projects are taking place. We question the validity of thinning as a means both to reduce the threat of wildfire and to restore historic forest structure in the absence of site-specific data collection on past and present landscape conditions.

Soil Nitrogen Cycling following Montane Forest Conversion in Central Sulawesi, Indonesia

The lower montane forest zone of Indonesia is undergoing rapid conversion of indigenous forests to agriculture. In this tropical region, however, the effects of forest conversion on soil N processes have not been investigated. Corn (Zea mays L.) and cacao (Theobroma cacao L.)–coffee (Coffea canephora Pierre ex Froehner) agroforestry are the main land use types in cleared lower montane forests in Central Sulawesi, Indonesia. Our main objective was to compare the soil N dynamics under agroforest systems and corn cultivation with indigenous forest. We measured the gross rates of N transformation processes using 15N pool dilution. The agroforest systems and indigenous forests had higher gross N mineralization rates and faster turnover rates of NH4+ and microbial N pools than the long‐term cultivated corn sites. Faster soil N turnover rates in agroforest systems suggest a more dynamic soil N cycling. Leguminous shade trees, which are important components of these agroforest systems, may have influenced the fast microbial N cycling through release of N‐rich root exudates and plant residues. Our results show that compared with corn, agroforestry is a better option in terms of sustainability in the N‐supplying capacity of the soil. In addition, we measured higher 15NH4+ recoveries than 15NO3− recoveries after 15 min of 15N addition in all our sites. Our measured rates of gross nitrification were very low to negligible, due to rapid disappearance of added 15NO3− Such fast reaction of NO3− warrants further investigation, especially in tropical areas where 15N studies are very few.

Changes of dung beetle communities from rainforests towards agroforestry systems and annual cultures in Sulawesi (Indonesia)

Little is known about how tropical land-use systems contribute to the conservation of functionally important insect groups, including dung beetles. In a study at the margin of Lore Lindu National Park (a biodiversity hotspot in Central Sulawesi, Indonesia) dung-beetle communities were sampled in natural forest, young secondary forest, agroforestry systems (cacao plantations with shade trees) and annual cultures (maize fields), each with four replicates (n = 16 sites). At each site we used 10 pitfall traps, baited with cattle dung, along a 100 m transect for six 3-day periods. The number of trapped specimens and species richness at the natural forest sites was higher than in all land-use systems, which did not significantly differ. Each land-use system contained, on average, 75% of the species richness of the natural forest, thereby indicating their importance for conservation. However, a two-dimensional scaling plot based on NESS indices (m = 6) indicated distinct dung beetle communities for both forest types, while agroforestry systems and annual cultures exhibited a pronounced overlap. Mean body size of dung beetles was not significantly influenced by land-use intensity. Five of the six most abundant dung beetle species were recorded in all habitats, whereas the abundance of five other species was significantly related to habitat type. Mean local abundance and number of occupied sites were closely correlated, further indicating little habitat specialisation. The low dung beetle diversity (total of 18 recorded species) may be due to the absence of larger mammals in Sulawesi during historical times, even though Sulawesi is the largest island of Wallacea. In conclusion, the dung beetle fauna of the lower montane forest zone in Central Sulawesi appears to be relatively robust to man-made habitat changes and the majority of species did not exhibit strong habitat preferences.

Twentieth-Century Change in the Climate Record for the Front Range, Colorado, U.S.A.

The long-term climate records of the Mountain Research Station (MRS) at the University of Colorado cover a range of elevations from the lower montane forest zone (~2000–2400 m), through the upper montane forest (~2400–2800 m) and subalpine forest (~2800–3300 m) to the alpine tundra (>3300 m) on Niwot Ridge, Colorado. Temperature records from all four MRS sites and the additional high plains site of Longmont (1509 m) are analyzed for the period 1952–1997, after extraction of much extra data from the original thermograph charts. The records are adjusted for instrumental changes where necessary and all four records are judged to be homogenous. Contrasting temporal trends are uncovered at the various elevations with warming at middle elevations and absolute cooling above the treeline in the alpine tundra. The resulting increased surface-based lapse rates do not arise from changes in relative frequencies of airflow types as is shown by a synoptic analysis based on objective airflow indices. Lapse rate increases are most systematic for synoptic classes with westerly components and during fall, winter, and spring. Climate at high elevations of the Front Range appears to be responding in an unusual way to global-warming influences.

Twentieth-Century Change in the Climate Record for the Front Range, Colorado, U.S.A.

The long-term climate records of the Mountain Research Station (MRS) at the University of Colorado cover a range of elevations from the lower montane forest zone (~2000–2400 m), through the upper montane forest (~2400–2800 m) and subalpine forest (~2800–3300 m) to the alpine tundra (>3300 m) on Niwot Ridge, Colorado. Temperature records from all four MRS sites and the additional high plains site of Longmont (1509 m) are analyzed for the period 1952–1997, after extraction of much extra data from the original thermograph charts. The records are adjusted for instrumental changes where necessary and all four records are judged to be homogenous. Contrasting temporal trends are uncovered at the various elevations with warming at middle elevations and absolute cooling above the treeline in the alpine tundra. The resulting increased surface-based lapse rates do not arise from changes in relative frequencies of airflow types as is shown by a synoptic analysis based on objective airflow indices. Lapse rate increases are most systematic for synoptic classes with westerly components and during fall, winter, and spring. Climate at high elevations of the Front Range appears to be responding in an unusual way to global-warming influences.

Gyalectidium yahriae, sp. nov.(Lichenized Ascomycetes, Gomphillaceae) from Florida and Papua New Guinea

Abstract A new species, Gyalectidium yahriae Buck & Serus., is described from collections made on twigs in Quercus woods in Florida (U.S.A.) and from decorticated wood in the montane forest zone of Papua New Guinea. Its ascocarps are unknown, but it is easily characterized by hyphophores composed of a circle of triangular lobes and by masses of moniliform hyphae producing long cilia on their outer cells; its generic position in the lichen family Gomphillaceae is uncertain.

Hilpertia velenovskyi (Musci, Pottiaceae) New to the Arctic from Ellesmere Island, Northeastern Canada

Hilpertia velenovskyi (Schiffn.) Zander is reported new to Arctic. Hilpertia scotteri (Zander and Steere) Zander is treated as a synonym of H. velenovskyi, and a full description is given. This is only third locality known from North America of this now monotypic genus. Hilpertia velenovskyi is considered a xerophyte centered in Eurasia from central east Europe to China with northern disjunct populations in continental Asia, and disjunctions in Pre-Holocene refugial regions of Canada. While reading the red book of Pottiaceae (Zander 1993) text and illustrations of Hilpertia gave first author a hint as to a possible identity of a plant he collected in 1990 at Tanquary Fiord, Ellesmere Island, Arctic Canada, while joining Sylvia Edlund in field work. The identity of this plant was confirmed by second author as genus Hilpertia. This genus is unique among Pottioideae in elaboration of a photosynthetic organ consisting of thin-walled and hollow-papillose laminal marginal cells rolled in a spiral tube (Zander 1989). Only two previous records document presence of Hilpertia in North America. The first specimen was collected in 1977 by G. W. Scotter in Northwest Territories, District of Mackenzie, Nahanni National Park, and it formed basis for Tortula scotteri Zander & Steere (Zander & Steere 1978). The collection site was upper part of a lacustrine, calcareous deposit of silt mixed with minor portions of sand and clay. Phytogeographically, collecting site is located well within montane forest zone. The second specimen was collected in 1984 by T. McIntosh in British Columbia, Big Bar area, N of Lillooett in a shrub-steppe habitat. This specimen was also referred to Tortula scotteri. This collection came from semi-arid steppe of interior Cordilleran region. The third specimen, reported here, was collected by G. S. Mogensen in 1990 on Ellesmere Island, Tanquary Fiord, on marine shoreland beach of silt with some sand on a flat terrace about 5 m a.s.l. These plants (Fig. 1) occurred as scattered individuals or in to aggregations, with characteristics cabbage-head appearance as noted also by McIntosh (1989) in his specimen. Phytogeographically, Tanquary Fiord site is located in high arctic region at 81?23'N. Taxonomy.-Zander (1993) recognized two species of Hilpertia: H. velenovskyi (Schiffn.) Zander and H. scotteri (Zander & Steere) Zander, former of Eurasia and latter endemic to Canada. Tan and Zhao (1997) reported new finds from China and new observations in morphological variation of H. velenovskyi in western and alpine China, both in leaf morphology and in operculum shape. They drew conclusion that two species are conspecific i.e., that H. scotteri is a synonym of H. velenovskyi. We concur with this conclusion. Geographic distribution.-Tan and Zhao (1997) summarized phytogeographic distribution of Hilpertia velenovskyi (including H. scotteri) as having a broad northern boreal range. This characteristic does not apply to Canadian populations which are all confined to xeric habitats in steppe, montane forest, or high arctic regions. We note that localities in China also are xeric. Furthermore, we note that both collection from Nahanni River and from high arctic dessert are located in regions with incomplete glacial cover during later stages of Pleistocene. In light of this information we prefer to consider H. velenovskyi a xerophyte centered in Eurasia, occurring from eastern Europe to China with northern disjunct populations in continental Eurasia and Canada. We are aware of specimens only from Northern Hemisphere, but have noted that Van der Wijk et al. (1969) cited presence of Tortula velenov0007-2745/99/753-755$0.45/0 This content downloaded from 157.55.39.100 on Thu, 25 Aug 2016 05:07:22 UTC All use subject to http://about.jstor.org/terms 754 THE BRYOLOGIST [VOL. 102 :1 bI ,'i ;?; ~ In I i a i ?: v, I ~ -~ ~ ::: 9) !3: O

Polish Mountain Forests: Past, Present and Future

Mountains occupy only 3% of Poland. They are the northern part of the European arc of the Carpathian and Sudety Mountains, extending about 700 km along the southern Polish border. They are of medium height (about 1500 m, maximum 2600 m a.s.l.), and have diversified climate, geology, soils, vegetation, and anthropogenic impacts. The forest vegetation of the Sudety and Carpathian Mountains form three elevational zones. Forests occur in the foothills (as high as about 600 m a.s.l.), the lower mountain forest zone (as high as about 1250 m a.s.l.) and the upper montane forest zone (as high as 1500 m a.s.l.). The original lower mountain forests consisted mainly of fir ( Abies alba Mill.) and beech ( Fagus sylvatica L.), while upper montane forests contained spruce ( Picea abies (L.) Karst.). Centuries of economic activity have changed the species composition of mountain forests. Spruce has increased considerably, and the percentage of fir and beech has decreased significantly. In the Sudety and western part of the Carpathians spruce is the most prevalent (as high as 83%), while in the eastern part of the Carpathians it does not exceed 10%. The percentage of beech in the Sudeten and western Carpathian forests is less than 20%, while it is about 40% in the eastern part of the Carpathians. Severe weather conditions, frequently poor habitats, and improper management and considerable air pollution occurring in the past 50 years, followed by infestations of primary and secondary insects and spread of parasitic fungi, have led to considerable destruction of these mountain forests. According to forecasts the area of totally destroyed and severely damaged mountain forests will increase considerably through 2010. Deterioration of forest health will proceed from west to east. Protection of forest health against deterioration requires reduction of industrial emissions, changing existing forests into genotypes that are less sensitive to air pollution and more compatible with local habitats, and recultivation of deteriorated forests.

Variation in Morphology and Functional Traits of Dictyonema Glabratum From Contrasting Habitats in the Venezuelan Andes

AbstractSpecimens of Dictyonema glabratum from various elevations in the Venezuelan Andes show clear differences in morphology. Optimal development of thalli is attained in the lower Paramo at 3500–3600 m; at the upper altitudinal limit of distribution at about 4300 m only poorly developed thalli are found; in the montane forest zone at about 1700 m the thalli attain about half the average surface area and two thirds of the thickness of those in the optimal habitat. The histological structure of the thalli also shows significant differences. The relative volumes of photobiont to mycobiont, as an indicator of the relationship autotrophism/heterotrophism, is 1.6:1 in specimens from the upper Paramo; 0.9:1 in open habitats on the lower Paramo; 0.5:1 in shaded habitats; and 1.4:1 in the montane forest. The three altitudinal morphotypes are not only distinguished by structure but also by carbon dioxide gaseous exchange patterns. Specimens from the optimal habitat exhibit the highest photosynthetic capacity. The respiration activity reflects a homeostatic adjustment to the prevailing temperature regime: the respiration of specimens from 4300 m at 1°C approximates to same intensity as that of D. glabratum from the lower Paramo zone at 6°C. Nevertheless, metabolic homeostasis is only possible over a narrow temperature amplitude. On account of the large heterotrophic component in lichens, at altitudes below 1500 m where the temperature average is 20°C or more and the nocturnal temperatures are constantly high, the dry matter consumption due to respiration would become extremely high. This suggests that D. glabratum may be limited in its downward distribution by an increasingly unfavourable carbon budget.

山地ポコットの生態人類学的研究

The Pokot of western Kenya is a tribe of the Kalenjin group belonging to Southern Para-Nilotes, whose territory, lying across the Great Rift Valley, shows wide varieties of natural environment. The author mainly investigated Upland Pokot who inhabit the altitudinal zone of approximately 2000-2500m in the eastern slope of Cherangani Hills (3500m at the highest), from the viewpoint of ecological anthropology for five months in 1978. Lower zone of the slope (ca. 2000-1000m at altitude) constitutes the northern end of Elgeyo Escarpment, eastward of which expands into the plain of dry bush where Pastoral Pokot inhabit. Hill-side Pokot occupy the foot fringe of the escarpment, where they carry on irrigation forming.The habitat of Upland Pokot above the escarpment can be included in the montane forest zone in original flora. Homesteads of families and their fields lie scattered on the slope, and they subsist mainly on agricultural products, however, they also herd livestock on a small scale in their habitat zone except fenced fields. At each small village alongside the road running at the foot of the escarpment, market is held once or twice a week, where the dwellers of Upland, Hill-side and Plain gather with their products, barter them each other, and trade with merchants and wageworkers coming from outside.In this paper, the author describes and analizes the natural environment of Upland Pokot, their ways and means of subsistence, some aspects of social life reflected on the manner of naming and community organization, and mutral relations among them. Further, their relationship will Hill-side and Plain Pokot is analized through the situation of intermarriage and market exchange. Then, it is discussed how the subsistence style of each habitat group is regulated by and adapted to the natural environment, and how social and economic factors, on the other hand, have been related to the divergence of subsistence styles among the Pokot.