Monteverde Institute: Tropical Ecology and Conservation

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  Duet response songs and territorial defense in the gray-breasted wood wren (Henicorhina leucostica Troglodytidae), November 2009

  Ali Corley

  Bird song serves a wide variety of functions. Avian duetting is one form of bird song that is especially common in the tropics but whose function is still not well understood. The Joint Territorial Defense and Acoustic Mate Guarding hypotheses explain duetting as either a cooperative form of song, in which a pair is working together to accomplish a common goal, or conflicting form of song, in which each bird in a pair is singing for individual motives. Under Joint Territorial Defense theory, pairs sing duets to better defend their territories. The Acoustic Mate Guarding theory predicts that pairs sing duets because one bird in the pair joins its mate’s song to prevent solo singing and thus repel stranger birds of the same sex that pose a threat to their partnership. This study presented conspecific playbacks of solo and duet songs to the territories of paired Gray-breasted Wood-wrens (Henicorhina leucostica) in Monteverde, Costa Rica to determine the purpose of duet response songs. There was a higher likelihood of response to duet playbacks than to solo playbacks in the form of song or physical approach. There were ten out of 15 song responses to duets and only three out of 15 song responses to solos. Approaches to speaker were observed ten out of 15 times for duets and only two out of 15 times for solos. Also, for the pairs that responded to both playback types, the song characteristic measurements of high, maximum and delta frequencies in the response songs were significantly lower for duet playbacks than for solo playbacks. Both results support Joint Territory Defense over Acoustic Mate Guarding as the primary function of response duetting.

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  Effect of Cecropia polyphlebia, Cecropia obtusifolia, and Bidens pilosa on human lung capacity, November 2009

  Michelle Gin

  Traditional medicine is used by 80% of the world population as their primary care. Monteverde, Costa Rica houses a rich flora including Cecropia polyphlebia (Cecropiaceae), Cecropia obtusifolia (Cecropiaceae), and Bidens pilosa (Asteraceae) that have been identified as medicinal plants to reduce the symptoms of asthma and other respiratory ailments. Fifty-eight human subjects were divided into four groups of tea treatments, including Chamomile Chamaemelum nobile (Asteraceae) as a control. Lung capacity was measured using the amount of air blown into a balloon in a single breath. Initial (pre-treatment) as well as the immediate and long-term effects of plant extracts on lung capacity were measured for the four tea treatments. Results showed no statistically significant difference between the immediate and long-term effects of any of the treatments. However, there was a statistically significant difference between B. pilosa and C. obtusifolia; B. Pilosa and C. nobile; and C. polyphlebia and C. nobile. B. Pilosa and C. polyphlebia are most effective to increase one’s lung capacity and, therefore, most likely to lessen asthma symptoms.

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  Effect of the parasite Ophryocystis elektroscirrha on asymmetry and wing color of the monarch butterfly, Danaus plexippus, November 2009

  Emily Landeck

  Ophryocystis elektroscirrha, a protozoan parasite, can have many different effects on the Monarch Butterfly, Danaus plexippus, including difficulty emerging from the pupal case and spreading their wings, and increased mortality within 24 hours of eclosion. Color in the wings of the butterfly is a strong indicator of fitness in terms of reproductive success. In this study I test if parasite load has an effect on the fitness of individuals of D. plexippus using color of the wings as a proxy for fitness. I measured the wingspan; asymmetry of forewings; color hue, saturation, and brightness; and parasite load on 15 individuals of D. plexippus. There was a trend in the differences of the wingspan averages between infected and uninfected individuals: infected individuals had an smaller average wingspan, a negative trend between the wingspan and asymmetry, and positive trends between the wingspan and the two wing color values of hue and brightness. These trends could be caused by the activation of the parasites in the pupal stage of development in smaller butterflies. Therefore larger individuals have brighter more defined colors in their wings and less asymmetry, probably indicating fitter butterflies.

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  Effects of inbreeding on morphology and reproduction in Morpho peleides (Nymphalidae), November 2009

  Brittany Pahnke

  Populations limited in dispersal ability have higher rates of inbreeding and lower gene flow than large, well-connected populations. Inbreeding depression causes some morphological characteristics to change predictably in butterfly populations, and these may therefore be indicators of overall fitness. I examined differences in body size and symmetry between wild-caught Morpho peleides individuals and individuals from an inbred population to observe the effects of inbreeding on morphological characteristics. Inbred butterflies had lower average forewing length than wild ones, and thus lower overall body size, but there were no detectable differences in asymmetry. Body size was positively correlated with body mass, and body mass was found to be positively correlated with fecundity, which may have serious consequences for establishment of future generations in inbreeding butterfly populations. This finding is an example of how alteration of a morphological trait can constrain an important life history trait, fecundity.

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  Effects of satiation on pit-trap structure in the larval antlion Myrmeleon crudelis (Neuroptera Myrmeleontidae), November 2009

  Zack Newman

  Sit-and-wait predators have many strategies to deal with food scarcity. Some predators become more active, while others conserve energy by becoming more sedentary. I decided to test the effects that starvation has on the larval antlion Myrmeleon crudelis. Myrmeleon crudelis build pit-traps, conical structures built in sand, to capture prey. These pit-traps vary in diameter, depth, and angle for each larva. Seven individuals in one group were fed every other day, while seven other individuals were starved for all ten days this study took place. The pit-traps of both groups were then compared to each other. The results show that as larval size and feeding frequency increase so do the diameter, depth, and angle of pit-traps. These results suggest that Myrmeleon crudelis chooses to become less active in the presence of food scarcity.

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  Effects of Trichoderma harzianum perimeter applications on preventing Mycena citricolor in Coffea arabica plots, November 2009

  Nicholas J. Gallagher

  This study examined the fungus Trichoderma harzianum, a proven effective biological control agent, for its potential of preventing the forest and windbreak instigated onset of the fungus Mycena citricolor in coffee plots. Fifteen plots on one farm in the Monteverde region of Puntarenas, Costa Rica were surveyed for the presence of M. citricolor on coffee near forest edges and along transects away from the forest. T. harzianum was applied to the forest edge on half of the plots, and the coffee plants near the edge were resurveyed for new infestations of M. citricolor. No significant difference between the treated and untreated plots was found. Other factors such as humidity and light exposure may have influenced the onset enough to nullify the fungicide’s effects over such a short length of time. A regression analysis of the transects confirmed that the presence of M. citricolor decrease with increased distance form the forest. This may also be attributed to the levels of light and humidity along the transects. Less time limited experiments may still prove edge applications of T. harzianum an effective method for inhibiting M. citricolor inception in coffee plots.

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  Homegardens of Monteverde: Exploring changes in home crop cultivation, November 2009

  Abigail Smith

  Homegardens are model forms of sustainable land use in tropical agroforestry systems. Known as an assembly of varied crops and animals, these small homestead farms provide a cheap, nutritional source of food to the family while maintaining the biodiversity and productivity of the surrounding ecosystem. With the introduction of ecotourism into the Monteverde area, an economy traditionally based on agriculture shifted towards tourism services, thus changing the underlying dynamics of the community. Thirty families of the Monteverde area were interviewed and provided information relating to homegarden contents, family history, and lifestyle choices. This study shows that homegardens have declined significantly in diversity of both crops (F = 37.5210, p = <.0001) and livestock (F = 17.8885, p = <.0001), and that these changes are largely due to the urbanization and influx of tourism into the area. Changes in homegarden production, and also community structure, will have varying socioeconomic, cultural, and environmental impacts on the region.

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  Impact of intraspecific and interspecific competition on aggression and foraging of hummingbirds (family Trochilidae), November 2009

  Whitney Tsai

  Hummingbirds have high metabolic needs and many aggressively compete for food. Competition is a potentially important component of resource defense but its impact on aggression and foraging of hummingbirds is not well understood. I manipulated the perception of competition by using the playback of the Coppery-headed Emerald (Elvira curpeiceps), a territorial hummingbird, and of the Violet Sabrewing (Campylopterus hemileucurus), a traplining hummingbird, to assess the impact on number of aggressive chases and foraging success of hummingbirds at feeders. This study was performed in Monteverde at the Monteverde Cloud Forest Preserve and Selvatura Park. The playbacks caused some but not all hummingbird species to be more aggressive and forage less often. Specifically, intraspecific and interspecific competition between the territorial species, increased aggression (mean value before: 1±0.34; mean value after: 2.92±0.29) and decreased foraging time (mean value before: 12±3.21; mean value after: 6.75±1.95). Interspecific competition between the trapliner and the territorialist increased aggression for the territorialist (mean value before: 0.29±0.50; mean value after: 2.71±0.29), but not the trapliner (mean value before: 2±0.63; mean value after: 2.4±0.66;), while foraging was not affected for either (territorialist, mean value before: 14.53±3.75; mean value after: 10.88±3.84: trapliner, mean value before: 9.57±2.22; mean value after: 9.38±1.41). These results suggest that intraspecific competition impacts foraging and aggression more than interspecific competition, and that foraging behavior plays a role in competition.

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  Incidence of pigment change in Werauhia (Bromeliaceae) uncorrelated with canopy cover level, November 2009

  Rachelle Sloss

  The study of plant adaptation to changing habitat is particularly important in the face of continuing habitat destruction in the tropics. Habitat fragmentation will likely increase light intensity for tropical flora in these areas. Plants often respond to such changes by increasing concentrations of secondary pigment, like anthocyanins and carotenoids, as a photoprotective mechanism. Plants may also increase the ratio of chlorophyll a:b in high light because they have less need for shade-adapted accessory pigments like chlorophyll b. However, in the Werauhia bromeliads studied, average anthocyanin and carotenoid concentrations decreased while chlorophyll a:b ratio increased. The decrease in anthocyanins and carotenoids suggests a decrease in light intensity, while an increase in chlorophyll a:b ratio indicates an increase in light intensity. Due to local climate observations of the study site and the indication of the anthocyanin and carotenoid decrease, I believe that the plants experienced an overall decrease in light intensity. This suggests that the increase in chlorophyll a:b ratio found was due to other environmental factors. However, these contradictory findings suggest that further study is needed to determine effects of light intensity on Werauhia.

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  Leaf choice in Dryas iulia (Nymphalidae Heliconiinae) cyanide content and toughness, November 2009

  Ashley Arthur

  Vines in the Passifloraceae synthesize cyanogenic glycosides that deter general herbivores, but Heliconiinae butterfly larvae such as Dryas iulia have overcome this and utilize Passiflora leaves as larval food. Ovipositing adult females and larvae may access the suitability of leaves caused by various plant defenses such as cyanide content and leaf toughness. D. iulia adult females show no preference in cyanide content (9.01μg ± 28.3, 5.77μg ± 12.6) or toughness (238.67g ± 78.4, 266.58g ± 123.1) for ovipostion, yet larvae prefer leaves with a significantly lower cyanide content (9.01μg ± 28.3, 0.47μg ± 0.51) then the average available leaf but average toughness (238.67g ± 78.4, 227.23g ± 80.7). This indicates that larvae are assessing plants to maximize fitness and D. iulia ovipositon is determined by more factors then simply Passiflora leaf cyanide content and toughness.

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  Orchid fragrance complexity as a mechanism for Euglossine bee pollinator specialization, November 2009

  Luci Moore

  Neotropical orchids of subtribes Stanhopeinae and Catasetinae are exclusively pollinated by euglossine bees (Euglossini). This study determines whether orchids present specific combinations and proportions of chemical odors in order to attract a limited subset of euglossine bee species, thereby avoiding hybridization that may result from the attraction of too many pollinators. Chemical baits of cineole, benzyl acetate, methyl salicylate, cineole/benzyl acetate (a Stanhopea tricornis fragrance analogue), and cineole/methyl salicylate/methyl benzoate (a Catasetum gnomus fragrance analogue) were used to attract fifteen species of euglossine bees in the San Luis Valley, Monteverde, Costa Rica. The diversity of bee species attracted to the cineole/benzyl acetate solution was significantly lower than either cineole or benzyl acetate (Shannon-Weiner index; for cineole/benzyl acetate: H’ = 0.89; for cineole: H’ = 1.91; for benzyl acetate: H’ = 1.82; for cineole/benzyl acetate and cineole: F = 4.89, df = 68.00; for cineole/benzyl acetate and benzyl acetate: F = 5.66, df = 64.29, p < 0.05). The diversity of species attracted to the cineole/methyl salicylate/methyl benzoate solution was significantly lower than cineole (ShannonWeiner index; for cineole/methyl salicylate/methyl benzoate: H’ = 0.82; for cineole: H’ = 1.91; F = 6.16, df = 61.25, p < 0.05). The results provide evidence that orchid fragrance complexes are designed to attract specific euglossine species that are both effective pollinators and specialized enough to reduce risk of interspecific outcorossing.

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  Resource allocation to vegetative versus reproductive structures in Piper sp, November 2009

  Melissa M. Martinko

  Resource allocation theory in plants dictates that resources utilized for one physiological process are unavailable for another, and that plants must selectively allocate critical resources in order to maximize their fitness. Therefore, resources allocated to reproductive growth are unavailable for vegetative growth and vice versa. The relationship between vegetative and reproductive growth was examined for a common Piper species found in San Luis, Monteverde, Costa Rica by comparing the size of leaves with opposing inflorescences on the same node to the size of leaves without opposing inflorescences on the same node. A total of 18 Piper plants with mature inflorescences were sampled, eight in forest edge locations and ten in forest understory locations. There was no difference in average length (t = -0.695, df = 358, P = 0.4877) or average width (t = 0.271, df = 358, P = 0.7864) between leaves with opposing inflorescences and leaves without opposing inflorescences. Thus, resource allocation to reproduction did not translate into a reduction in vegetative production of leaves in Piper sp. Alternatively, diversion of resources to reproduction may manifest itself as a reduction in other vegetative structures such as roots or stems, or as a reduction in other plant processes such as herbivore and pathogen defense.

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  Rodent diversity in relation to Atlantic and Pacific slopes in a neotropical cloud forest, November 2009

  Justine Smith

  Mountainous regions in Costa Rica are characterized by windward/leeward effects caused by easterly trade winds and orographic cloud formation. The Pacific slope is generally drier and more seasonal compared to the Atlantic slope. These factors tend to favor higher biodiversity for a given taxon on the Atlantic slope. Live traps were used to test this for a tropical Cloud Forest rodent community on either side of the Continental Divide. Six species were captured overall. All six species were present on the Atlantic slope and three were present on the Pacific slope. As predicted, rodent diversity, including richness and evenness, was significantly higher on the Atlantic slope than the Pacific slope. The proportion of P. mexicanus in comparison to other species was higher on the Pacific slope. The results indicate that climatic factors are principle drivers of rodent diversity. It appears that generalist and dry-adapted species are outcompeting and potentially causing range shifts in other native species. Alterations in abundance and range may be due to regional climate fluctuations and the flexibility of species to adapt to these changing conditions.

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  Shifts in flowering phenology in response to irregular precipitation and temperature patterns in Monteverde, November 2009

  Wynn Moss

  Studies of plant flowering phenology have the potential to provide essential information on the structure and function of communities. Additionally, shifts in flowering phenology as a response to local weather variability have been observed in the tropics, and may worsen as the effects of anthropogenic climate change increase. Unfortunately, comprehensive data on the phenology of many Monteverde plant species is unavailable. This survey of 79 flowering plants of Monteverde in October and November of 2009 aimed to determine the effects of El-Niño on the timing of anthesis as well as provide new information on the phenology of local plant species. Seventy-nine species of flowering plants were identified, ten of which were flowering irregularly. The atypical flowering was not significantly distributed over geographic areas or pollinator type. This suggests that the effects of local climate variation extend across plant types and may have large implications for the functioning of this community.

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  Site fidelity in two species of Cyclocephala (Scarabaeidae) to Xanthosoma robumstum (Araceae), November 2009

  Margaret Hendricks

  Mark and recaptured methods were utilized to determine the site fidelity of two species of scarabid pollinators to a patch of Xanthosoma robustum in Monterverde, Costa Rica. Sex ratios remained constant with previous studies, exhibiting a higher proportion of males found per inflorescence than females. One-way ANOVA tests of variance supported evidence that female Cyclocephala are more prevalent in first day inflorescences. One-way ANOVA tests also concluded that scarab pollinators exhibit no fidelity to the study patch, The existence of a more resource rich patch in the area could account for the low fidelity observed. The selection for low fidelity through differential spadix heating in Xanthosoma may be utilized to promote genetic variance within the patch.

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  Size-related niche-partitioning of epiphytic orchids in Cloud Forest canopies, November 2009

  Blaine Marchant

  Ten recently fallen trees in the Lower Montane Wet Forest (1550-1650 m) and Lower Montane Rain Forest (1650 m to 1800 m) of Monteverde, Puntarenas, Costa Rica were each divided into four zones based on tree architecture. Each zone theoretically represents differences in substrate and abiotic conditions: Zone 1 was the main trunk, Zone 2 the inner third of the canopy, Zone 3 the second third of the canopy, and Zone 4 the outer-most third of the canopy. The epiphytic orchids of each tree were surveyed to determine the role of weight in epiphytic orchid distribution among the different zones of the tree. In total, 335 individual orchids were weighed and identified to genus and then distinguished by morphospecies and analyzed to test for variation in species richness and weight among the four zones. Total species richness was equally distributed among the four zones, however, when size specific genera were analyzed for species richness distribution alone, there was variation in species richness between zones. In addition, there was an overall variation in weight among zones. The outer-most region of the canopy, Zone 4, had the smallest orchids (18.25 +/- 67.63 g), while the inner-most region of the canopy, Zone 2, had the largest orchids (67.76 +/- 113.11 g). In conclusion, I found that weight does play a role in the niche-partitioning of epiphytic orchids in the Cloud Forest of Monteverde.

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  Spatial dispersion of fruits and foraging optimization of frugivorous bats, November 2009

  Kristen Omori

  Optimal foraging helps maximize fitness of the disperser and corresponding plant. Fruiting strategies may influence foraging success in order to increase seed dispersal rate. This study examines the spatial dispersion of fruits and its influence on foraging time of frugivorous bats. Five bat species in captivity at the Bat Jungle in Monteverde, Costa Rica, including Carollia brevicauda and Artibeus toltecus, are used to test the foraging time on three spatial arrangements, uniform, random and clumped, using a natural food source, Solanum umbellatum (Solanaceae). Each of the three arrangements were tested for fruit removal rate during one day and two of the trials that were not tested in the morning of the first day were preformed the two following mornings. The bats were able to forage the quickest on the clumped arrangement of fruits (15:27min) suggesting that it is most advantageous for plants to ripen their fruits in clusters to maximize fruit removal rates. However, the foraging time for random arrangement was only one minute more than for clumped in the morning trial, suggesting that the bats may be able to adopt different foraging strategies to optimize search time.

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  Sucrose concentration preference in nectarivorous bats, November 2009

  Kyle Bevers

  Nectarivorous bats perform vital pollination services for many tropical plant species. While nectarivorous bats have been shown to prefer higher percentages of sucrose in past studies, bat pollinated flowers usually offer a lower sugar concentration in the nectar, equal to 18 percent sucrose on average, thus forcing bats to visit more flowers. Visiting flowers increases outcrossing, pollination, and subsequently, plant fitness. This study attempts to see where bat’s preferences, if any, exist for sucrose within the natural range of bat pollinated flowers. For nine nights, bats were observed at Selvatura Park in Monteverde, Costa Rica, where they forage at hummingbird feeders at night. Bats were observed foraging on prepared solutions of 10, 15, 20, 25, and 30 percent sucrose. No significant difference was found in foraging between different concentrations of sucrose, although some trends were apparent, indicating that bats may prefer higher concentrations of sucrose.

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  The abundance of the vector insect, Triatoma dimidiata (Reduviidae) and the ecology of infection with Trypanosoma cruzi, November 2009

  Erica Vargas

  A study was conducted in the Monteverde region to determine patterns of infection in Triatoma dimidiata with Trypanosoma cruzi. It was predicted that proximity to domestic animals and looking at the sex ratio would reveal patterns of infection in T. dimidiata. This study was conducted in San Luis, and 12 properties were searched for T. dimidiata. Fourteen individuals were found overall at four sites with two infected individuals. However, the two infected individuals were found in close association with dogs. Fewer nymphs than expected were found this year. Weather patterns of the region could account for the low abundance of T. dimidata. Abundance from past years was also compared to 2002 and 2003. Another long-term study is needed to better understand the dynamics of Chagas disease in the Monteverde area.

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  The applicability of the river continuum concept to the upper reaches of a neotropical lower montane stream, November 2009

  Nicholas Skaff

  The applicability of the River Continuum Concept (RCC) to the upper reaches of Quebrada Máquina, a lower montane stream in Monteverde, Costa Rica, was examined. Macroinvertebrate samples were taken from ten points along the stream from first through fourth order segments. The families of the collected individuals were then categorized based on functional feeding group. The similarity between the families found at each collection point was calculated, along with correlations between the functional groups and various stream characteristics. In most cases, RCC predictions did not apply to Quebrada Máquina. The first (first order) and last (fourth order) sample points were 92% similar despite RCC predictions of substantial divergence in relative functional group abundance. This digression from the RCC predictions may be caused by the relatively few differences in stream characteristics between first and fourth order sections. Specifically, the observed similarities and correlations may have been determined by local scale heterogeneity of the stream characteristics.

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  The effect of land use on stream water quality in San Luis and Cañitas, November 2009

  Anna Stuart Burnett

  Human altered landscapes often have significant impacts on water quality in their respective watersheds. However, in order to create policy and educate people about better land use practices, it is necessary to have a thorough understanding of the effects of land use on stream water quality. This study looks at the health of stream water in three streams flowing through different land uses – forest, cattle pasture, and coffee – in San Luis and Cañitas in the Monteverde area. Water quality was determined using biotic and abiotic indicators. The abiotic indicators included dissolved oxygen, temperature, nitrogen, phosphorus, pH, and turbidity. Macroinvertebrates were sampled for the biotic indicators, which included the number of taxa (families) per site, and the Biological Monitoring Working Party Index (BMWP). The sites were compared in terms of similarity using a Morisita index of similarity. The Morisita index showed that similarity between sites was more likely a result of the stream the sample was taken from than the land use it was taken in. Overall, the sites all had regular to high water quality according to the BMWP scores, indicating good land use practices. There were no significant correlations between the biotic and abiotic indicators of water quality. Combined with the good water quality of the streams, this study indicates that there was too little pollution in the streams to have a significant impact on the macroinvertebrate communities. This study can provide comparisons to future studies on streams with more pollution as well as aid in determining the tipping points for abiotic factors that result in macroinvertebrate declines.

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  The effects of habitat heterogeneity in the parasocial orb-weaver Metabus gravidus (Araneae: Araneidae), November 2009

  Sara Wilbur

  Metabus gravidus (Araneae: Araneidae) is a colonial, orb-weaving spider, conspicuous along streams and rivers in Central America. These spiders construct individual webs along anchor lines spanning small waterways, placing foraging spiders in areas of high insect traffic. Riparian habitats are characterized by heterogeneity of physical factors, such as rainfall, temperature, and cloud cover. The purpose of this study was to determine the effects of habitat heterogeneity on daily M. gravidus presence. M. gravidus individuals in webs were counted daily in nineteen colonies along La Quebrada Máquina in Monteverde, Puntarenas province, Costa Rica. Abiotic conditions, such as previous 24-hour rainfall, temperature, cloud cover, rainfall during measurements, and wind intensity, were recorded. None of the abiotic factors considered in this study had a significant impact on the numbers of M. gravidus present. Although abiotic factors are normally important determinants in spider establishment, the unique habitat occupied by M. gravidus is likely to render these usually damaging factors insignificant.

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  The role of extrafloral nectaries and saponins in plantherbivore interactions of Inga sierrae (Fabaceae: Mimosaceae), November 2009

  Kevin Davis

  Trees of the Neotropical genus Inga are noted for the use of extrafloral nectaries (EFNs) and secondary compounds to protect against herbivores. For Inga sierrae, the production of Extra-EFNs (EEFNs) has been suggested to confer fitness on fledgling leaves, while the role of saponins on herbivory remains unclear. This study investigates the potential trade-off between EEFN and saponin production and its effect on herbivory. I recorded percent herbivory on fledgling leaves during a three week period and measured saponin contents for I. sierrae trees at two different study sites at 1525m in Monteverde, Costa Rica. Encounter surveys were conducted to assess the associated herbivore populations. EEFN production, saponin content, percent herbivory, and herbivore abundance varied between study sites. There was a weak negative correlation between EEFNs and percent herbivory. Differences in proximity to continuous forest between study sites may be causing observed differences in herbivore abundance, and in turn, percent herbivory. Future studies should focus on the effect of saponin content on herbivore preferences and fungal and lichen infestation.

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  Understanding the effects of secondary succession on soil nutrient concentration and soil macro-invertebrates, November 2009

  Rebecca Goldstein

  When agricultural land is abandoned, secondary succession is known to occur within the plant community, but little is known about the effects of regeneration on the soil. Since plant richness and productivity is tightly correlated with nutrient availability, I investigated the effect of time after regeneration on nutrient levels and macro-invertebrate richness. I sampled six sites ranging in age of regeneration (0 years, 7 years, 11 years, 19 years, 45 years, and primary) measured at the concentration (lb/acre) of potassium, phosphorous, iron, and nitrate nitrogen and counted the morpho-species richness. Potassium and phosphorous concentrations were significantly correlated with age of regeneration; iron concentration was marginally significant when correlated with age of regeneration; but, nitrate nitrogen was not significantly correlated with age of regeneration. Morpho-species richness was positively correlated to regeneration time as well. Differences in trends in potassium, phosphorous, and iron may be due to differences in nutrient cycling on a geological scale and movement of water across surfaces. Lack of significance with nitrate nitrogen may signify a difference in the distribution of nematodes. Morpho-speices may or may not ever return to primary levels, however they do increase compared to pasture levels. In conclusion, secondary succession has an effect on soil in terms of both abiotic and biotic conditions.