Forest In Taiwan Research Articles

Throughfall Patterns in a Subtropical Rain Forest of Northeastern Taiwan

AbstractThroughfall chemistry of a subtropical rain forest in Taiwan was examined for 3 yr to understand patterns of nutrient inputs to the forests of this region. Annual throughfall fluxes for NH+4, NO−3, and SO2−4 (89, 28, and 83 mmol/m2/yr, respectively) were close to the levels of the most polluted areas in the temperate region. The lack of major emission sources near the study site indicates that most of the pollutants were regional and/or international in origin. High rates of cation leaching from the forest canopy were evident and the pattern is similar to that seen in heavily polluted temperate forests. Typhoons played a central role in the hydrology of the study forest with eight typhoons contributing 26% of the total rainfall in 320 h over the three years monitored. This typhoon input represented 20% of the total precipitation flux of the ions found in seasalt aerosols but less than 10% of anthropogenically enriched ions. Canopy leaching was an important source of base cations in throughfall and NO−3 was retained in the canopy. Using the Na‐ratio method the contribution of dry deposition relative to precipitation input was estimated to be 40% in the summer and 10% in the winter. The contribution of dry deposition to total deposition is small relative to many temperate forests and might result from the lack of long dry periods between precipitation events. Net throughfall flux was negatively related to precipitation concentration for H+, NH+4, NO−3, and SO2−4, suggesting that passive movement was important in characterizing throughfall dynamics.

Diversity and distribution of the mangrove forests in Taiwan.

In a survey of 1992 to 1994, mangrove forests withfour species of true mangroves, Kandelia candel(L.) Druce, Avicennia marina(Forsk.) Vierh.,Rhizophora stylosaGriff., and Lumnitzera racemosaWilld., were found at 22locations in the west coast of Taiwan. The northernrange of their distribution was at Tanshui Estuary(Latitude 25°11′N) and the southern range atTapen Bay (22°28′N). The total area wasestimated to be 286.95 ha. There was an obvious changein species composition and a decrease in speciesnumber of true mangroves from south to north: the fourspecies dominated by A. marinain thesouth and K. candelas thesole species in the north. Air temperature associatedwith sea surface temperature and oceanic currents inwinter, but not soil property, was found to be theprimary environmental factor, affecting the diversityand distribution of true mangroves in Taiwan as wellas in the northeast region of Asia.

A Preliminary Analysis of Chemical Characteristics of Atmospheric Pollutants and Their Deposition Budget on the Fu-shan Forest in Taiwan

This paper presents the chemical characteristics of atmospheric pollutants measured at the Fu-Shan forest (620 m MSL) during two two-weeks field experiments held in the summer and winter of 1993. Chemical compositions of these atmospheric pollutants in solid, gaseous and liquid phases were analyzed. The deposition budget of Sand N compounds through dry and wet deposition pathways were particularly assessed. As a result, aerosol mass spectra were found to be bimodal, having the 50% cut size ＜ 1.0 μm and around 3.2μm for fine and coarse modes, respectively. In summer, fine and coarse modes were primarily composed of ammonium sulfate and nitrate, respectively. But, in winter the coarse mode was dominated by sea salts due to the influence of northeast monsoon flows. Our average HNO2 (~0.10 ppb) was appreciably higher than those observed in clean troposphere, whereas HNO3 was at a comparable level. Meanwhile, ammonia gas and particulate ammonium were at a lower concentration level compared with those generally observed on the continental grounds. The SO2 (＜1 ppb) was comparable with those frequently observed in the free troposphere, while SO42- was close to the lowest level typically obtained in urban areas. In addition, NO3- which is thought to be associated with local pollution was limited. Therefore, we believe that excessive sot, to a larger extent, was transported to the site via long-range transport, particularly in winter. With regard to the deposition budget, wet deposition pathway (＞ 90 %) was the most effective mechanism for delivering atmospheric S and N compounds to the Fu-Shan forest during the periods of our field experiments.

Short-run and long-run efficiency measures for multiplant firms

The usual Data Envelopment Analysis (DEA) model for measuring the relative efficiency assumes that all plants belong to distinct firms superior to them. For firms with more than one plant, Koopmans proposes a procedure for deriving the short-run production frontier for each firm. Modifying his idea, a DEA model is constructed in this paper for measuring the short-run efficiency of each plant within a firm. Based on the theory of production economics that the long-run production frontier is an envelop super-imposed upon all short-run production frontiers, another DEA model is constructed to measure the long-run efficiency of every plant. The long-run efficiency is always smaller than or equal to the short-run efficiency. Consequently, it is possible that an inefficient plant can only be improved in the long-run. With the models constructed in this paper, a decision-maker is able to distinguish between what can be achieved in the short-run and what in the long-run. To clarify the idea, an example of Taiwan forests is adopted for illustration.

Distribution of the radionuclide 137Cs in the soils of a wet mountainous forest in Taiwan

The behavior of 137Cs was studied in the Yuanyang lake ecosystem, a wet mountainous forest in subtropical Taiwan. Soils investigated are either partially podzolic soils or nearly pure peats with a high organic matter concentration in the surface layer. Concentration of 137Cs was highest in the organic surface layers, particularly in the Oe horizon or in the underlying A horizon. The downwards migration to the mineral horizons is limited, in spite of the high rainfall. Topography is a critical factor for the distribution of 137Cs. It is shown that the concentration of 137Cs is highest at the foot of the slope and lower near the summit and near the lakeshore. The variation of the concentration along the landscape has been attributed to erosion–deposition in combination with surface run-off of the undisturbed forest. The amount of 137Cs in the site studied is significantly higher than at any other place in Taiwan. The accumulation of 137Cs is attributed to the high rainfall, which brought large amounts of 137Cs with the precipitation in the early 1960s. A very remarkable feature of the ecosystem is that 137Cs is not leached to the subsoils, but is stored in the biomass. Due to permanent recycling it remains available, without being leached downward.

Seasonal Activity, Reproduction, and Diet of a Riparian Frog (Rana swinhoana) from a Subtropical Forest in Taiwan

Seasonal Activity, Reproduction, and Diet of a Riparian Frog (Rana swinhoana) from a Subtropical Forest in Taiwan

Typhoon Disturbance and Stand‐level Damage Patterns at a Subtropical Forest in Taiwan1

ABSTRACTWe examined the typhoon wind disturbance regime of the Fu‐Shan Experimental Forest in northeastern Taiwan. Mean number of typhoons passing within 200 kilometers of Taipei (40 kilometers from the site) was 1.4 per year. Category 4 and 5 typhoons, which are intense enough to uproot large numbers of trees, occurred every 8.3 and 12.5 years respectively, although it is likely that some category 4 and 5 typhoons did not produce extensive blowdowns at Fu‐Shan because the area of maximum winds missed the study site. Uprooting was more common than snapped boles; the most common damage to trees, however, was probably defoliation, although this damage was not quantified in the current study. Thirty‐five percent of wind‐damaged trees were associated with a gap. Six percent of the land area was in gaps. Canopy turnover time was calculated at 175 years when all gaps ≤ 9 years old were included in the calculation, but the time decreased when older gaps were excluded from the calculation. Turnover time was somewhat higher than calculated for other tropical forests. Because turnover time increases as the percent of land in gaps decreases, the short life span of gaps at Fu‐Shan probably contributed to our higher calculated time. Probability of being damaged was not related to tree species identity, and only a few species of trees were found regenerating in gaps. Principal Components Analysis indicated that damaged trees varied largely in treefall orientation and aspect; gaps varied primarily in aspect and in gap size.

First record of the occurrence of Sporodiniella urnbellata (Mucorales) in Taiwan

During an investigation of mucoraceous fungi indigenous to soil of old-growth forest in Taiwan, an entomogenous fungus identified asSporodiniella umbellata was encountered. It has a sporangiophore with a conspicuous umbellate habit with sterile spines and sporangia, and was found growing on dead insect,Acraea issoria-formosana andDanaus plexippus. Description of the specimens and living cultures are provided, along with illustrations of taxonomically important structures. Artificial inoculation ofS. umbellata on larvae of mealworm resulted in the radial growth of young sporangiophores emerged from the test larvae.

Spatial Variability of Throughfall in a Subtropical Rain Forest in Taiwan

AbstractEight rainfalls were intensively sampled in a subtropical rain forest in northeastern Taiwan. This study, carried out at Fu‐shan Experimental Forest was designed to examine variability of throughfall characteristics. The volume and chemistry of the throughfall associated with individual rains have a high degree of spatial variability, with throughfall chemistry more variable than volume. When data from all of the storms were combined, there was lower variability than that seen with individual storms, largely as a result of a lack of consistent storm to storm spatial variation. Thus, individual storms cannot be used to represent the seasonal or annual pattern of spatial variation in throughfall chemistry or volume of the study forest. Twenty samples were required to estimate throughfall volume within 10% of the population mean with 95% confidence for individual storms. Yet, more than 100 samples were required to estimate the throughfall chemistry of some ions (e.g., H+). When the data from all eight storms were combined, 7, 20, and 25 samples were necessary to estimate throughfall volume, ion concentrations, and ion fluxes (except for Mg2+ and H+) within 10% of the population mean with 95% confidence. In the absence of estimates of spatial variation, differences in sampling protocols among throughfall studies make comparisons of throughfall characteristics difficult. In this study three funnels were used in tandem to capture small scale variability at each sample location, thus reducing spatial variability of throughfall chemistry.

Biodiversity and Conservation of the Evergreen Broad-leaved Forests in Taiwan

台湾における高い人口密度と急速な経済発展にもかかわらず，常緑広葉樹林は引き続き台湾島の面積の32% を占めている。この森林は海岸域から海抜2500 m に分布し，多様な植物相と4 つの主要森林型を支えている。779 の調査区での森林の植物相は木本植物570 種を含み， 234 属， 82 科に及んでいる。最も種の数が多い科はクスノキ科，ブナ科，ツバキ科，アカネ科， トウダイグサ科であった。本研究の第１の目的は，台湾における常緑広葉樹林の4 主要型について比較解釈をすることである。第2 の目的は過去3 世紀に亘るこれらの森林の管理と保護の状況を概括することである。

Data Envelopment Analysis in Measuring the Efficiency of Forest Management

One major concern in environmental management is how to manage efficiently the scarce natural resources necessary to improve the standards of life. To this end, a tool is required to measure the relative efficiency of the management achievements. In this paper, an approach entitled data envelopment analysis (DEA), which is widely used in management science, is introduced to measure the efficiency of forest management. The detailed steps in application, some technical problems to be noticed and the models available for selection are described. In addition to measuring efficiency, the DEA approach can also be used for generating directions for making improvements. A real case of Taiwan forests in used as an example.

Measuring the Efficiency of Forest Management

Abstract In managing forests, the relative efficiency of management accomplishments should be evaluated to obtain a guideline for future planning. However, to evaluate whether a multiple-use forest is efficiently managed is very difficult bemuse many outputs do not have market values. In this paper a model based on the principle of Pareto optimality is introduced for measuring the efficiency of forest management. The model is of a linear fractional program which can be converted to a linear program. The aggregate efficiency of a management unit can be separated into technical and scale efficiency to enable the manager to identify the sources of inefficiency. From the dual formulation of the linear program, the inefficient inputs and outputs can also be identified together with the amounts by which they can be improved. As an illustration, the model is applied to measuring the management efficiency of the 13 districts of the National forests of Taiwan, Republic of China. Surprisingly, the results perfectly explain a current proposal of the Taiwan Forestry Bureau. For. Sci. 37(5):1239-1252.

Integrated pest management of several forest defoliators in Taiwan

The main defoliators in plantation forests of Taiwan are the casaurina tussock moth ( Lymantria xylina), the pine caterpillar ( Dendrolimus punctatus), the leucaena psyllid ( Heteropsylla cubana), the coconut leaf beetle ( Brontispa longissima). Formosan alder leaf-beetle ( Linaeidea formosana), and the bamboo mirid ( Mecistoscellis scirteloides). Integrated pest management of these insects shows promise. The casaurina tussock moth has been effectively controlled by aerial spray of insecticide and a microbial agent, Beauveria bassiana. The pine caterpillar can be killed by spraying a mixture of extracts from three microorganisms. The coconut leaf beetle and bamboo mirid can be controlled by the use of parasites in incooperation with insecticide use. The Formosan alder leaf-beetle damage to alders can be avoided by planting alder with other tree species or by the use of resistant varieties.

Plant-sociological studies on the natural occurence of Camphortree Forests in Taiwan (1)

Plant-sociological studies on the natural occurence of Camphortree Forests in Taiwan (1)

Plant-sociological studies on the natural occurence of camphortree forests in Taiwan (2)

Plant-sociological studies on the natural occurence of camphortree forests in Taiwan (2)