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Research |
Fu-shan: Result of the first phase of study
The first phase of the study concentrates on site preparation (such as gauging subwatersheds, establishing meteorological stations, designing long-term vegetation plots etc.), monitoring of physical environments (such as climate, hydrology and soils moisture regimes etc.), biological survey and inventory for flora, fauna and microorganisms of the site. Initial measurements of flux rates of processes of the forest ecosystems (e.g. elemental budgets and cycling, nutrient movement in the riparian zones etc.) are also studied. Some of the available results are summarized as following. Acknowledgement is due to the following.
A weather station was established at the nursery near administration building to monitor weather at the site. Two sub watersheds (WS1 and WS2) are selected in the headwater of Ha-pen-chi. Watershed WS1 (37.0 ha.) was gauged 90-degree V-notch and a rectangular weir to accommodate exceptional floods. A series of rain gauges were also placed to monitor rainfall and discharge with data loggers . Watershed WS2 covering an area about 100 ha is currently under construction.
Within WS1, a 20-m tall meteorological observation tower was elected. Above canopy level meteorological parameters were monitored which include rainfall, wind speed, wind direction, air temperature, humidity, global solar radiation, photosynthetic active quantum flux, reflected solar radiation, total hemispherical radiation, terrestrial radiation, and net radiation. At the ground level, soil temperature and soil heat flux were also measured. Hourly extremes, means and/or total values of the monitored parameters were recorded. Additional 10-minute logged interval programs can also be easily activated to provide a detailed environmental background for other related research programs. All these recorded data have been compiled and can be easily accessed by other researchers. A 16-m scaffold was also erected adjacent to the meteorological observation tower which provided access to the canopy level. Currently, this scaffold is used as a mounting mast for above canopy rainfall collectors. As fog plays a significant role in the hydrological cycle at the Fu-shan area, fog collector will be deployed on this scaffold in the near future. An energy budget calculation, which includes evapotranspiration, is one of the major research topics at this site and will be investigated cooperatively with plant water relation research colleagues.
Nutrient budget and cycling
Principal Investigators: Hen-biau King, Teng-chu Lin and Lih-chi Wang
The major studies include chemistry of acid deposition (bulk and wet), nutrient budgets, elemental cycling, throughfall dynamics, accumulation and transformation of soil nutrients, soil solutes transport, and streamwater chemistry of the Fu-shan forest.
Wet deposition was sampled using Andersen automatic precipitation collectors. Bulk precipitation samples are collected using both funnels mounted on the top of a tower above tree canopy and funnels 1-meter above ground in a cleared ground. Through fall is sampled using both troughs (2-m long by 30-cm wide and 20-cm tall) and a sets of funnels 50-cm above ground under the forest canopy in designated plots. Stemflow samples are collected by trapping all trees larger than 10-cm in diameter within a 15x15 m2 plot. Soil solution samples are collected using soil solution cups installed at various depths in the same plots as for throughfall and stemflow collection. Movements and chemistry of lateral soil solutes in riparian zone are studied with drainage collectors. Sufficient replicates are designed to meet the requirements for statistical testing. Water samples are extracted from stream of the gauged watershed using two ISCO water samplers. One is programmed to collect weekly flow proportional composite samples for total nutrient output estimation. The other is programmed to extract water samples at 5 minutes interval during storm periods to study hydrological processes. All water samples are subject to chemical analysis for pH, conductivity, suspended sediments, total nitrogen, base cations, anions, and trace elements.
Forest vegetation
Principal Investigators: Tzer-tong Lin
The purpose of this study is to establish baseline data on the forest community of the Fu-shan Forest and correlate growth parameters of forest community with environmental variables.
Fifty-three plots (each plot consists of 1 to 5 quadrants, each quadrant is 100 m2 in size) for a total of 215 quadrants were established. In each plot tree species were identified and their dominance was classified. Six environmental variables were selected and assumed relating to the development of the forest community of the study site. These were altitude, slope, aspect, topographic position and whole light sky space. An aspect-topographic synthetic index was derived. The forest community was classified, using two-way indicator species analysis. In order to obtain the variation gradient of the forest community the detrended correspondence analysis (DCA) was adopted as the ordination of forest community. The correlation between gradient of the forest community and the environmental variables is used to interpret the significance of each environmental variable in question.
It was found that the forest community distribution was significantly correlated with the altitude, topography, aspect, whole light sky space and aspect-topography synthetic index. Four types of forest community were recognized. These were:
Milk fig tree (Ficus erecta var. beecheyana) type, a secondary forest at valley bottom;
Taiwan phoebe (Phoebe formosana) type, a natural forest at valley bottom;
Yellow basket willow (Engelhardtia roxburghiana) type, a natural forest at mid-slope; and,
Chinkapin (Castanopsis carlesii var. sessilis) type, a natural forest at upper slope extending to the ridge.
Understory vegetation
Principal Investigator: Chen-meng Kuo
This project is to characterize the understory vegetation, particularly the herbs and shrubs of the Fu-shan forest site. Eighty sampling plots (5m x 5m each) located along both sides of a transect which extended from the ridge of Ha-pen-chi watershed (about 1,400 m at the high peak) down to the valley about 1000 m in elevation, were established. Five line intercepts were selected randomly within each sampling plot. For each line intercept several sampling points were located at 1-m increment, where the plant species was identified and the length that species covered was measured and recorded. Some selected habitat variables (i.e. altitude, aspect, slope, etc.) were described and accordingly an aspect-topographic synthetic index was derived. Total 52 species of herbs were recorded. By applying the cluster analysis, two-way indicator species analysis and detrended correspondence analysis the herbs of the Fu-shan forest could be grouped into three communities: ridge, slope and valley communities. The boundary between each community ranged from diffuse to continuous. The valley community is dominated by Diptazim dilatatum, Elatostema lineolatum and Elatostema edule. This dominance is gradually shifted to Selaginella doederleinii and Dicranopteris linearis when approaching to the ridge. Three distribution types of the herb species were recognized. These were ridge, slope ecotone and valley types. The shrubs, 29 species in total, of the study site could not be differentiated into either community or distribution type but they showed diffuse shifting patterns from the valley to the ridge similar to those of herbs. The variations in understory vegetation community and species distribution type were correlated with habitat characteristics such as altitude, soil moisture regime and the aspect-topographic synthetic indices.
Biomass and nutrient accumulation
Principal Investigators: Kuo-chuan Lin and Fu-wen Horng
Estimates the dynamics of accumulation and distribution of primary nutrients of the Fu-shan Forest at two succession stages were made by establishing two sampling plots representing stands at developing and subclimax stages, respectively. All trees in the plots and all shrubs and herbs in subplots were randomly selected within the plots, and were removed, weighted and calculated to estimate the primary nutrient storage of the stands. At the same experiment the leaf area index of the stands were also calculated.
The aboveground biomass of the stand in developing stage was 196.9 ton/ha, of which 75.5% was composed of trees and 2.6% was litterfall layer. The aboveground biomass of the stand in subclimax stage was 289.6 ton/ha, of which 93.6% was composed of trees. The majority of biomass concentrated in trees below 11.3m in height. According to leaf area index, the dominant species was Castanopsis carlesii var. sessilis at the developing stage and Machilus thunbergii at the subclimax stage. The leaf area index (LAI) of the trees in subclimax-stage stand (5.83) was larger than that in developing stage stand (2.81), indicating that the upper canopy of the former was larger than that of the latter. The aboveground biomass and LAI of the subclimax-stage stand in Fu-shan area were insignificantly less than those of the same type of stand in the central Taiwan (Lien-hua-chi area). Compared with tropical rain forest with similar annual rainfall, the subclimax-stage stand in Fu-shan area accumulated less biomass but with similar LAI. This may be explained by the disturbances of typhoons in Fu-shan Forest, which affected the accumulation of biomass, but leaf biomass recovered rapidly after the disturbances. The low aboveground biomass and LAI of the developing-stage stand may be controlled by the processes of gap regeneration.
Invertebrates
Principal Investigator: Yau-chi Chu
A preliminary survey was conducted to investigate the soil fauna of the forest floor using quadrat method. Bait traps were also applied to collect saprophagous and necrophagous menmbers. The arthropods dwelled in the decaying tree trunks were identified and animal feces in the samples were also collected and identified. The methods and the experimental procedures were described briefly as follows.
To investigate the Xylophagous decomposer, a tree trunk of the predominant tree species, Castanopsis carlesii var. sesslis, was dissected into logs (about 25-cm long and 25-cm in diameter) which were used as traps. Thirty-six such logs were prepared and left on the forest floor. Differences between fauna found in the cut logs and in coarse organic debris of natural decaying tree trunks were compared. Three of them were cut monthly and the arthropods found were studied . Fauna in the litter layer were collected with quadrats (50-cm by 50-cm) and in the humus layer they were collected with stainless steel open-both-end boxes, 10-cm(L) by 10-cm(W) by 5-cm(H). Soil fauna in the animal feces were also collected and identified.
There were 523 species , or 122 families, or 15 orders of insects, of which 240 species, or 52 families, or 10 orders were Acarina. Twelve species or 14 families of Chilopoda, Diploda and Crustacean were found in this survey.
Amphibians and reptiles
Principal Investigator: Kuan-yang Lu
The purpose of this study was to monitor changes of herpetological fauna (amphibians and reptiles) of the Fu-shan forest over time so as to learn the impacts of environmental change on the fauna of the study area. Special attention was also placed on the interrelationships of the herpetological fauna and the animals associated with them.
Two long-term monitoring sites were selected: a semi-natural pond in the botanical garden and the Har-pan-chi, main brook of the nature reserve of the Fu-shan forest. The characteristics of the habitat was described and was related to the activities of the fauna under investigation. The survey frequency was 1 to 2 times per month and visual encounter method was performed for both sites. Population changes were studied using capture, mark and recapture method. Species diversity as well as their behaviors, abundance, time and locality of appearing were recorded.
Preliminary results showed that there were 12 species of frogs found both in the nature reserves and in the pond, with additional 2 more species only located in the pond. The 12 species of frogs were Buergeria robustus, Bufo melanostictus, Chirixalus idiootocus, Hyla chinensis, Polypedates megecephalus, Rara guentheri, Rara kuhilii, Rara latouchi, Rara longicrus, Rara sauteri, Rara narina swihoana, and Rhacophorus smaragdinus. And the additional 2 species of frogs were Racophorus taipeianus and Rara adenopleura. The species diversity between the two sites probably attributed to the differences in habitat characteristics. The population of frog showed species-specific seasonal variation patterns except one species, Rara adenopleura, the population change of which was little regardless the time of the year. Nine species of snakes were recorded. They were Bioga kraepelini, Elaphe teaniura friesei, Dinodon rufozonatum, Naja naja atra, Natrix percarinata, Preas formosensis, Psammodynastes pulverulentu s, Sibynophis chinensis, Trimeresurus mucrosquamatus and Trimeresurus stejnegeri.
Bird communities
Principal Investigator: Lien-shang Chou
This investigation was aimed to study the composition, guild structures, mixed-species flocks and breeding of bird community of Fu-shan forest site. The composition survey was carried out at predetermined sites and time alone fixed transects through random focal observing bird flocks. Parameters, such as foraging, spatial positions, behaviors and food types of different bird species, were statistically analyzed using cluster analysis to indicate characteristics of the guild structure. The first-year study identified 72 bird species, of which 57 (or 79%) were resident species. The most predominant species was Chinese White Eye (Alcippe morrisonia). It appeared that seasonal variation of bird species was evident both for the numbers which peaked in the winter (November and December) and the individual frequency. Of total 72 species observed, 49 were found in the natural forest, 60 in the botanical garden, 8 along the trail and 7 around the administration building. The structure of 29 species observed show three distinct guilds : pond carnivores, raptors and insectivorous tits on upper canopy. The mixed-species flocks were composed of 12 resident species, among them Chinese White Eye was the most common species. During the reproductive season, from late to July, breeding frequency and aggressive behavior increased obviously.
Principal Investigator: Tung-chu Chang
This study included investigating the macrofungi in general and the monthly population dynamics of Aphyllophorale in Fu-shan forest site and to correlate the biology of the microflora with climatic parameters. More than 100 Aphyllophorales specimens were collected. Among them, 30 genera or 54 species have been identified, with 18 species are not identified yet. Some of the species are new records to Taiwan.
The investigation of Aphyllophorales basidiocarps was carried out once a month for 13 months from November, 1992 to November, 1993 along a natural trail of the site. Twenty -two known species of Aphyllophorales were found and identified. Among them, Microporus affinis (B1. et Nees ex Fr.) Kuntz., Fomitopsis rhodophaeus (Lev.) Imaz. and Ganoderma australe (Fr.) Pat. appearing every month and are most prevalent. Of which, M. affinis was the most dominant species. Besides the three prevalent species listed above, 7 species were seen more than eight months during the survey and possessed moderate dominance. They are Trichaptum biform (Fr. in K1.) Pil., Stereum ostrea (B1. et Nees) Fr., Trametes versicolor (L. : Fr.) Pil., T. hirsuta (Wulf. : Fr.) Pil., Rigidoporus microporus (Fr.) Overeem , Phellinus membranaceus Wright et Blument , and Inonotus iodinus (Mont.) Cunn. The remaining was considered as rare species. Since the appearing frequency and quantity of F. rhodophaeus and G. australe were consistent ly low. No correlation was found between their appearance and climatic variables. However, appearing frequency of M. affinis was significantly and positively correlated with monthly rainfall and the number of rainy days in a month, but not among the appearing frequency of M. affinis, monthly mean temperature, and monthly mean relative humidity.
Acknowledgements
The results of this report were summarized from the results of the first phase of each study conducted by the principal investigator(s) of the specific research project. Appreciation and credits should be extended to the following contributors:
Hydrometeorology: Yue-joe Hsia, Lih-chi Wang, Jeen-liang Huang and Teng-chiu Lin of Taiwan Forestry Research Institute and Neng-huei Lin of
The Central University;
Nutrient budget and cyclings: Hen-biau King, Teng-chiu Lin and Lih-chi Wang of Taiwan Forestry Research Institute;
Forest vegetation: Tzer-tong
Lin of Fu-shan Resaerch Institue,
Taiwan Forestry Research Institute;
Understory vegetation: Chen-meng Kuo of National Taiwan University;
Amphibians and reptiles: Kuan-yang Lu of National Taiwan University;
Bird communities: Lien-shang Chou of National Taiwan University and
Mammals: Ling-ling Lee of National Taiwan University.
This research program is supported by grants from the National Science Council and Taiwan Forestry Research Institute, Republic of China.
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