|USFLDC Home | Tropical Ecology Collection [Monteverde Institute]||| RSS|
This item is only available as the following downloads:
xml version 1.0 encoding UTF-8 standalone no
record xmlns http:www.loc.govMARC21slim xmlns:xlink http:www.w3.org1999xlink xmlns:xsi http:www.w3.org2001XMLSchema-instance
leader 00000nas 2200000Ka 4500
controlfield tag 008 000000c19749999pautr p s 0 0eng d
datafield ind1 8 ind2 024
subfield code a M39-00017
Riqueza de la comunidad de Macrohongos a diferentes distancias de un arroyo en el bosque nuboso
Macrofungal community richness at different distances from a cloud forest stream
The purpose of this study was to examine macrofungal community richness at different distances from the Quebrada Mquina in the cloud forest of Monteverde, Costa Rica. Twenty transects no closer than ten meters apart were tested. Each transect contained a 1X 1 m2 plot positioned at zero, five, ten, fifteen, and twenty meters from the stream edge. Fungi were counted and photographed and weather and substrate type were recorded. I predicted to find more macrofungal richness closer to the river because of water and sunlight availability. However, using Friedmans method for randomized blocks, I found a Chi squared value of 9.18 (df = 4, p > 0.05), which shows no statistical significance in fungal community richness between the five different distances. However, graphing mean number of species found per distance, we can see a trend. It shows that fungal richness is highest at the middle distances. I also tested distribution of species on substrates, and found dead wood was the most common. A Chi squared Goodness of Fit Test (assuming substrate abundance was equal) showed that the distribution differed significantly from the expected distribution (Chi squared = 315.5, df = 5, p < 0.001). These results therefore imply that there may be more dead wood at the middle distances than at the closest and farthest distances, or that other conditions are more favorable to fungi there.
El propsito de este estudio fue examinar la riqueza de la comunidad de Macrohongos a diferentes distancias de la
Quebrada Mquina en el bosque nuboso de Monteverde, Costa Rica.
Text in English.
Macrofungi--Costa Rica--Puntarenas--Monteverde Zone
Cloud forest ecology--Costa Rica
Macrohongos--Costa Rica--Puntarenas--Zona de Monteverde
Ecologa del bosque nuboso--Costa Rica
Tropical Ecology 2008
Ecologa Tropical 2008
t Monteverde Institute : Tropical Ecology
1 Macrofungal community richness at different distances from a cloud forest stream Elizabeth Place Department of Biology, University of Wisconsin-Madi son ABSTRACT The purpose of this study was to examine macrofunga l community richness at different distances from th e Quebrada Mquina in the cloud forest of Monteverde, Costa Rica. Twenty transects no closer than ten meters apart were tested. Each transect contained a 1X 1 m2 plot positioned at zero, five, ten, fifteen, and twenty meters from the stream edge. Fungi were coun ted and photographed and weather and substrate type were recorded. I predicted to find more macrofungal richness closer to the river because of water and sunlight availability. However, using Friedmans me thod for randomized blocks, I found a Chi squared value of 9.18 (df = 4, p > 0.05), which shows no st atistical significance in fungal community richness between the five different distances. However, grap hing mean number of species found per distance, we can see a trend. It shows that fungal richness is h ighest at the middle distances. I also tested distr ibution of species on substrates, and found dead wood was the most common. A Chi squared Goodness of Fit Test (assuming substrate abundance was equal) showed tha t the distribution differed significantly from the expected distribution (Chi squared = 315.5, df = 5, p < 0.001). These results therefore imply that the re may be more dead wood at the middle distances than at t he closest and farthest distances, or that other conditions are more favorable to fungi there. RESUMEN El propsito de este estudio fue examinar la riquez a de la comunidad de macrohongos a diferentes distancias de la Quebrada Mquina en el bosque nub oso de Monteverde, Costa Rica. Veinte transectos no ms cercanos a diez metros fueron probados. Cada t ransecto contena una cuadrcula de 1X 1m2 posicionada a cero, cinco, diez, quince, y veinte m etros del borde del arroyo. Se contaron los hongos y se fotografiaron y se tom adems el clima y el tipo d e sustrato. Predije encontrar mayor diversidad de macrohongos ms cerca al ro debido al agua y dispo nibilidad de la luz del sol. Sin embargo, usando el mtodo de Friedman para los bloques aleatorizados, yo encontr un Chi cuadrado valor de 9.18 (df = 4, p > 0.05) que no muestra difrencia en la diversidad fun gica entre las cinco distancias diferentes. Sin emb argo, al graficar el nmero promedio de especies encontra das por distancia, puedo ver una tendencia. Muestr a que la diversidad fungica es ms alta en las distan cias medias. Yo tambin prob la distribucin de la s especies en los substratos, y encontr la madera mu erta es el ms comn. Un Chi Cuadrado con Pruba de Bondad y ajuste (asumiendo que la abundancia del su bstrato es igual) mostr que la distribucin difiri significativamente de la distribucin esperada (Chi -cuadrado = 315.5, el df = 5, p <0.001). Estos resu ltados implican por consiguiente que hay a puede haber ms madera muerta a las distancias medias que a las distancias ms cercanas y lejanas, o que otras cond iciones all son ms favorables para los hongos. INTRODUCTION Fungi are a diverse group of organisms that play an important role in the environment. They aid in recycling organic matter b ack into the ground to be reused by other organisms such as plants and animals (Mata 19 99). They gain their nutrients in the form of carbon through absorption, not fixation. Du e to this characteristic, fungi are able to utilize many different types of carbon sources a s food (Alexopoulos et al. 1996). Some of these common substrates include dead wood, leaf litter, root tips, live trees, and soil.
2 Some environmental factors that affect fungal growt h and community richness are moisture, temperature, pH, oxygen, and sunlight (Al exopoulos et al. 1996). Since fungi live in such close relations with their environment due to their absorptive diet, slight changes in some of these factors can cause a change in species composition and community richness. Also, different fungi thrive in different or stricter climates, which can change the fungal richness in an area. For exam ple, most species of fungi have an optimal temperature range of 25r and 30r C. (Alexop oulos et al. 1996). Therefore, if this temperature constraint is not met, it will be diffi cult for many species to survive, which lowers community richness. The purpose of this study was to examine how distan ce from a water source affects community richness of fungi in the cloud fo rest of Monteverde, Costa Rica. Different distances from the Quebrada Mquina shoul d have different levels of moisture and sunlight. Although sunlight is not required, it may greatly enhance fungal growth through introducing reproductive structures (Alexop oulos et al. 1996). Moving away from the river, shade generally increases because t here is more canopy cover from large trees. Also, moisture should decrease at greater di stances as water in the soil drains downward toward the river. I predict that this comb ination will lower community richness of fungi as distance increases. One substrate on which fungi are commonly found is dead wood. In a previous study conducted by a CIEE student, 58% of fungi fou nd were on dead wood (Herz 2004). In tropical forests, dead wood represents a signifi cant amount of carbon (Delaney et al. 1998). Therefore, more fungi should be found on dec aying wood because it is one of the more abundant carbon sources, which would foster a greater richness. I expect this to also increase richness at the closer distances because m ost substrates, including dead wood, should fall or roll down towards the river. MATERIALS AND METHODS Study Sites This study was conducted along the Quebrada Mquina in Monteverde. Transects were restricted to an elevational range of 1,460 m to 1,560 m and were no fewer than ten m apart in distance. Also, the study sites needed t o be accessible up to 20 m from the river, but in relatively undisturbed habitats. This premontane wet forest has an average rainfall of about 2.5 m per year (Clark et al. 2000 ). These data were collected during the wet season, from July 26 through August 1, 2008. Collection Methods An altimeter was used to find 20 transects within t he correct elevational range. Each transect was perpendicular to the river and co nsisted of five 1 X 1 m2 plots at zero, five, ten, fifteen, and twenty m from the waters e dge. Once a transect was selected, I marked the first plot at the rivers edge (zero met ers) and counted the macrofungi on all substrates, such as dead wood, live trees, leaf lit ter, soil, root tips, and rocks, up to eye level. I then moved five m further away from the st ream to choose the second 1 X 1 m2 plot. I continued this process up to a distance of 20 m from the river. The fungi were
3 photographed and the substrate, amount of canopy co ver, and weather were recorded. Also, an attempt was made to identify the species o f fungi found. Once all the data were collected, a Friedmans meth od for randomized blocks was used to see if there was a statistical difference i n the number of fungi species at different distances from the water. Also, the mean number of species per distance and standard error were calculated to view any possible trends i n fungal growth. Finally, I used a cumulative species curve to evaluate whether my sam ple was an exhaustive representation of the community. RESULTS A total of 33 species were found within the 20 tran sects. Five species were found at the zero m distances, seven were found at the fi ve m distances, 13 were found at each of the ten and 15 m distances, and four were found at the 20 m distances. Four species were identified at the genus level, four at the spe cies level, and one at the family level using Mata (1999) and Mata (et al. 2003). Also, the re were six different substrate types including dead wood, live trees, rocks, soil, leaf litter, and end of root systems. Twentyone of the 33 species were found on dead wood, seve n on leaf litter, two on soil, and one each on a live tree, a rock, and root tips. The tot al Chi squared value for these data was 315.5 (Table 1; p < 0.001, df = 5). This value was calculated assuming all substrate types were equally abundant in the forest. The data were analyzed using Friedmans method for randomized blocks. The Chi squared value was 9.18 (df = 4; p > 0.005). The mea n number of species ranged from 0.20 (SE = 0.10) to 0.65 (SE = 0.11); see Fig. 1. A cumulative species curve was graphed and a polynomial of best fit was added to show if t he sampling was representative (Figure 2). DISCUSSION This study examined fungal community richness in th e Monteverde cloud forest at different distances along the Quebrada Mquina. I predicted to find higher richness at the closest distance because of increased sunlight and moisture. However, the results show that this prediction was not supported by the statistical analysis. Although there is no statistical difference between the richness at t he five different distances, a trend can be seen in Figure 1. There is a peak in number of spec ies around the middle distances (10 and 15 m) rather than at the closest or farthest di stances. Also, the total Chi squared value for distribution of species on substrates shows the high variance from the expected number of species per substrate type. Finally, when looking at the cumulative species curve (Figure 2), the number of new species starts to plateau when moving up in plot number, suggesting that sampling was exhaustive bec ause few new species were found as sampling continued. These results imply that there may be more dead woo d at 10 m and 15 m from the stream edge or that conditions there are more favor able for fungal growth than at zero m and 20 m. This could be a result of the rate at whi ch the dead wood rots. According to Delaney (1998), quantity of dead wood peaks in mois t areas rather than wet or dry areas. In the very wet areas, dead wood rots more quickly than in the moist areas. Knowing that
4 dead wood is an important and abundant source of ca rbon for fungi, having less right near the wet water edge, due to more rapid rotting, could be an explanation for why there is less richness at the closest distance and more r ichness in the middle, more moist plots. Another possible reason for this trend could be the position of fallen canopy trees. These large, rotting trees provide abundant substra tes for many fungi. They also create gaps in which sunlight can reach the forest floor ( Longman et al. 1987). Since many of these trees fall towards the river, they are in mor e moist areas, which is favorable for most fungal growth. Also, the parts of the trees cl osest to the water will rot faster, leaving larger sections farther from the water. This is opt imal for many species because there is also abundant sunlight available to aid in growth. A third possible reason could be that the microclim ate under the canopy is more stable at the middle distances than at the extremes Soil that is exposed, as seen closer to the river, becomes more weathered which affects the growth of some organisms (Osborne 2000). This may also explain why there were fewer s pecies found at the 20 m distances, where most of the plots were right on the edge of t he hillside where erosion could be high. For further study, I would suggest doing more speci fic testing on pH and oxygen levels in the soil. Both of these factors, as menti oned before, affect fungal growth. Also, I would look at how sunlight directly affects growth by comparing open areas (less canopy cover) to closed areas (more canopy cover). Finall y, further study on the importance of dead wood as a substrate for fungi should be consid ered. Being a very common substrate does not necessarily mean that it is more abundant. It could imply that it is a better source of carbon for fungi, which would enhance gro wth, and, in turn, increase richness. Perhaps further examination of all of these factors combined could give a more exact answer as to why there is a tendency of higher fung al community richness at 10 m and 15 m from the stream. ACKNOWLEDGEMENTS This study would not have been possible without the help of certain individuals. First of all, I would like to thank Karen Masters for all of her time, patience, and effort, and for being our surrogate mom. I woul d also like to thank Pablo Allen, Moncho Caldern, and Tan ia Chavarria for answering any and all questions an d for all the laughs. Thanks to Jenni Dinwiddie for l etting me borrow her super neat camera. Also, thank s to Jenny Gaynor for being from Wisconsin and for alway s playing Mary Janes Last Dance by Tom Petty. Finally, thank you to the rest of the students for making this an experience I will never, ever forget LITERATURE CITED Alexopoulos, C.J., C.W. Mims, and M Blackwell. 1996 Introductory Mycology ed. 4. John Wiley & Sons, Inc., U.S.A., pp. 28-31. Arora, David. 1986. Mushrooms Demystified, 2nd ed. Ten Speed Press, Berkeley. Clark, K.L., Lawton, R.O., and Butler, P.R. 2000. T he Physical Environment. Monteverde, Ecology and Conservation of a Tropical Cloud Forest. N.M. Nadakarni and N.T. Wheelwright, editors. Oxford University Press, Oxford, pp. 15-30.
5 Delaney, M., S. Brown, A.E. Lugo, A.Torres-Lezama, and N. Bello Quintero. 1998. The Quantity and Turnover of Dead Wood in P ermanent Forest Plots in Six Life Zones of Venezuela. Biotropica 30(1):2 -11. Herz, K. 2004. Fungal species richness in relation to substrate penetrability and moisture on the Atlantic slope. CIEE. Spring Tropical Ecology and Conservation. Longman, K.A. and J. Jenk. 1987. Tropical forest a nd its environment 2nd ed. Longman Scientific & Technical: 37-39. Mata, M. 1999.Macrohongos de Costa Rica Vol. 1. Instituto Nacional be Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica, pp. 11-26. Mata, M., R. Halling, and G.M. Mueller. 2003. Macro hongos de Costa Rica Vol. 2. Instituto Nacional de Biodiversidad (I NBio), Santo Domingo de Heredia, Costa Rica, pp. 8-26. Osborne, P.L. 2000. Tropical Ecosystems and Ecologi cal Concepts. Cambridge University Press:40-43. TABLES AND FIGURES Table 1. Distribution of species on different subs trates and corresponding total Chi square value Substrate Observed frequency dead wood 21 live tree 1 leaf litter 7 root tip 1 rock 1 soil 2 Total Chi squared value 315.5
6 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0 m5 m10 m 15 m20 mDistanceNumber of species Figure 1. Mean number of species versus distance of plots and standard error. A slight trend is seen in that there are more species at middle distances.
7 0 5 10 15 20 25 30 35 0102030405060708090100110 Plot numberCumulative species Figure 2. Cumulative species curve. Plot number ref ers to the one by one meter area used five times in each of the twenty transects, to tally 100 plots. The points were graphed using a scatter plot and a polynomial of be st fit was added. The equation for this polynomial is y = -0.002x2 + 0.5094x + 1.1 214.