2012 SOUTHEASTERN NATURALIST 11(2):263–278 Algal Community Composition from Kaolin Recovery Ponds Located in Middle Georgia Joseph N. Dominy, Jr.1 and Kalina M. Manoylov1,* Abstract - This is the first floristic and ecological evaluation of small pond systems developed over different periods of time after seized kaolin mining operations. Assessment of the total algal assemblage was used to infer environmental conditions of the aquatic habitats and also provided information about the ecological health and integrity of the aquatic ecosystems. The main objectives of this study were to document algal community composition and discern the amount of time it takes for a mined pond to reach its high biodiversity of primary producers. Winter and summer samples were taken from a pond developing for two years after removal of kaolin and from a pond that was thirty years old. Both pond systems contained rich algal communities predominantly from Cyanobacteria, Bacillariophyta, and Chlorophyta; however, the 30-year pond had higher Shannon-Wiener diversity, richness, and evenness values in both sampling seasons. In winter, filamentous Zygnematales dominated algal communities in the 2-year pond, while the 30-year pond community was dominated by diatoms. In both sites, the most taxon- rich group was green algal representatives of Desmidiaceae. In summer, potentially toxin- producing filamentous Cyanobacteria of the Nostocales were recorded in the 2-year pond, while the 30-year pond had higher average algal cell evenness and few toxic Nostocales. The average abundance of 11 diatom species, seven green algae, and one representative each of Euglenophyta, Cyanobacteria, and Cryptophyta resulted in less than 20 percent overall similarity between the two ponds. Our findings suggest that after two years of development potentially harmful kaolin residues are removed by natural sorption processes and do not negatively influence primary producers. However, stabilization processes in those manmade ecosystems may potentially take more than two years to produce high species richness and prevent toxic algal blooms. Introduction In aquatic systems, diverse algal communities can be identified and used to infer the overall health of the environment. Researchers have considered ecological restoration or creation of new aquatic habitats as a means of increasing ecological value of degraded lands and conserving biological diversity (Bradshaw 1983, Cairns and Heckman 1996, Hobbs and Norton 1996, Naveh 1994). An example, of degraded lands, are those resulting from mining activities such as kaolin production. Central Georgia is rich in kaolin. Kaolin, or alumina-silicate, is a clay-like substance used in the production of rubber, plastics, paints, paper, and many other products. Kaolin clay is extracted from many locations in central Georgia and plays an important economic role in the state. The process of kaolin mining takes several years and involves many stages in which the kaolin !Department of Biological and Environmental Sciences, Georgia College and State University, Milledgeville, GA 31061. *Corresponding author - kalina.manoylov@gcsu.edu. 264 Southeastern Naturalist Vol. 11, No. 2 is removed. The process involves huge “cuts”, usually around 2 ha in size and with varying depth, in which the kaolin is removed from the area. After mining operations have ceased many sites are filled with water to produce man-made ponds, which have unclear ecological functions. Kaolin companies are vested in properly restoring these mined areas, where water quality is monitored regularly to produce an environment desirable for aquatic organisms (NRC 1992). Afterwards, the reclaimed lands are declared as suitable for a variety of uses including agriculture, forestry, and wildlife use (Georgia Mining 2011). Creation of aquatic ecosystems is deemed a good restoration practice (Brookes and Shields 1996) with the potential of complete ecosystem structure and function. The time it takes for ecosystem structure and function to reach their full potential is unknown. Full ecosystem potential is measured with community attributes like high biodiversity, high evenness, and absence of toxic algal blooms (Chalar 2008). Biodiversity assessment can allow for accurate prediction of ecosystem stability (McGrady-Steed et al. 1997). Maintenance of ecosystem integrity and preservation of biological diversity translates into valuable outcomes for any natural habitat and should not be measured with monetary or moral values (Pimentel et al. 1997). Ecosystem-wide research for manmade small lakes and kaolin recovery ponds is limited. Biological research of the relationship between algae and kaolin residue has been dominated by experimental work done by Guenther and Bozelli (2004). Algae and kaolin particles have been used for understanding sedimentation and sorption processes (Cuker 1987) as well as algal survival after kaolin dust coverage. Inorganic particles, dissolved oxygen, total phosphorus, and iron were reported to decrease over time in small recovery ponds, while other metals and organic carbon increased with time (Kalin et al. 2001). Due to the high remnant amounts of silicates and silicic acid, diatoms were reported as dominating clay and kaolin recovery ponds in Austria (Schagerl et al. 2010). A man-made pond over a landfill in Virginia was dominated by pennate diatoms and chlorophytes together with common Cyanobacteria after 10 years, while the algal community in the same pond was dominated by centric diatoms and coccoid greens after 20 years (Sheavly and Marshall 1989). Ponds provide important habitats for diverse floral and faunal communities, including a number of rare taxa of conservation interest (Wood et al. 2003). This paper examines the biodiversity and community attributes of primary producers from two recovery ponds after kaolin extraction. It was hypothesized that algal biodiversity can be used to predict recovery time of ponds after kaolin operations. Based on extensive literature search, this report is the first on algal species composition from kaolin recovery ponds in middle Georgia. Material and methods Field-site descriptions Algal communities were studied from aquatic locations at Gibraltar Mine, Wilkinson County, GA. Sampling sites were located within the Coastal plain region. Originally, 2-month, 2-year, 15-year, and 30-year recovering ponds were 2012 J.N. Dominy, Jr. and K.M. Manoylov 265 sampled. Due to safety procedure and restricted access, samples were collected during the months of February/March 2010 (winter samples) and June 2010 (summer samples). The sites were chosen based upon their age and repeated access. No algae were observed in the 2-month pond, and the 15-year pond was sampled only once due to limited access. The 2-year pond was located at 32°53'8.55"N, 83°5'30.23"W and had a surface area of about 0.53 ha with a maximum depth of approximately 2 m (Fig. 1; Georgia Encylopedia 2011). Low buffer zones covered with sparse grasses along embankments characterize the surrounding area. The 30-year pond was located at 32°54'15.70"N, 83°6'26.95"W and had a surface area of 3.4 ha with a maximum depth of 4 m. Increased vegetation surrounded the area, along with a tree line located 7 m upward from the embankment. Six samples in triplicate were obtained from each site and analyzed. The six distinct composite samples were taken using scrapings from various aquatic plants for epiphytic and attached algae, sediments for benthic algae, and three throws of a Turtox Tow Net (Wildco Ltd.) for water column collection for planktonic algae. Figure 1. An overview picture of the State of Georgia, Wilkinson County (indicated by a star), and the 30-year pond (top inset image) and the 2-year pond (bottom inset image). 266 Southeastern Naturalist Vol. 11, No. 2 Using composite samples decreases the amount of pseudoreplicates within a site (Hurlbert 1984). Water temperature and pH levels were measured using a YSI 556 Multiprobe System (YSI Inc., Yellow Springs, OH) at the time of collection (APHA 2005). Summer water samples for chemical analyses were collected in 500-ml acid-washed polyethylene bottles and sent to the University of Georgia for chemical analysis of inorganic nutrients, hardness, and ionic composition (Analytical Chemistry Laboratory, www.swpa.uga.edu). Water with hardness less than 85 mg/L is considered good quality drinkable water (APHA 2005). All samples were brought to known volume for relative cell density estimation (relative cells per mL) and concentrated. Fresh samples were kept on ice and observed within 2 hours of collection for best possible taxonomic identification using the natural color of algae and organelle structures. Algal samples for enumeration were preserved within 5 hours of collection in formaldehyde (3 percent final concentration). At least 300 natural algal units were enumerated in each sample. Enumeration of preserved samples was done in Palmer-Maloney counting chambers (Palmer and Maloney 1954). Natural counting units were defined as one unit for each colony, filament, diatom frustule (regardless if colonial or filamentous), or unicellular alga. If counting only individual cells, a large colony might underrepresent the number of algal taxa within complex photosynthetic communities; therefore, a minimum number of algal units were enumerated in each sample. Cells within a colony or filament were recorded. When colonies were multilayered and direct observation of individual cells was not possible, cell numbers were based on closest estimation. Identification of species continued after enumeration by scanning slides and recording presence of new algal species until no new taxa were observed on two consecutive semi-permanent flat slides. Species richness and cell relative abundance was calculated based on the total documented species (fresh observation after collection, 300-unit counts, and post-counts scanning). Observations for algal identification to the lowest taxonomic level possible were done at 400X under a Jenalumar (AusJena) microscope equipped with differential interference contrast (DIC), and images were captured with a Leica DM2500 color digital camera. Additional observations for taxonomic diversity were done on flat slides and under higher magnification as necessary. Current taxonomy followed Wehr and Sheath (2003), and the following references for specific algal groups were consulted: Bacillariophyceae - Krammer and Lange-Bertalot (1986, 1988, 1991a, 1991b), Patrick and Reimer (1966, 1975); Chlorophyta - Komárek and Fott (1983); Chrysophyceae - Starmach (1985); and Cyanobacteria - Komárek and Anagnostidis (1999, 2005). Collected material was archived and deposited as part of the algal collection of the GCSU Natural History Museum. For this study, dominant taxa were defined as more than 20 percent relative abundance of both units and cells from total recorded. Color digital images were taken of all taxa occurring in a sample at a relative abundance of five percent or more, with a goal of representing all taxa encountered at abundance of two percent or more in the study. Unknown taxa, potentially new to science were well documented also. 2012 J.N. Dominy, Jr. and K.M. Manoylov 267 Species richness, species evenness, and species diversity were calculated for each pond for all sampling dates. Species richness (S) describes the number of species (varieties or forms) recorded from a pond. The Shannon Index (H') considers species richness documented and proportion of each species out of total abundance recorded (Shannon and Weaver 1949). Maximum biodiversity (Hmax) was calculated as the natural logarithm of the documented total species richness number (Hmax = ln[S]). Species evenness (J'; Pielou 1969) was calculated as a proportion of the Shannon diversity and maximum biodiversity documented using the formula J' = H'/Hmax. Species diversity is a measure of ecosystem function that increases with either species richness or species evenness. Two community similarity indices that take under consideration presence/ absence of species and are not biased by small sample size or relative proportions were calculated. The Sǿrensen (1957) similarity index was calculated as S = 2C /(A + B), where C is the number of common species between two sites, A is the number of species in one site, and B is the number of species in the other site. Similarity varies from 0 to 1; high similarity is expected at 0.7 and above. For each pond as a whole, community similarity was calculated with the Jaccard index (Jaccard 1901), which is the number of species found at both locations (j) divided by the number of unique species (r) to either location combined (JI = j/r x 100). Statistical analyses To test if physiochemical characteristics differed between the sites, each characteristic was compared with a t-test (α = 0.05). If the assumptions for t-test were not met (e.g., normality, equal variance) and if transformation did not help, the Mann-Whitney non-parametric test was used. Descriptive statistics were conducted to analyze environmental variability and relationships between variables. Statistical analyses were performed with SYSTAT® 13 (Wilkinson 1989). A one-way ANOSIM was used to compare the ponds based on species’ relative abundance (untransformed and transformed data) with season nested within pond type. ANOSIM calculates test statistics, the R statistics, and gives stress values as a measure of the significance of the two-dimensional placement of sites on the ordination (stress value of more than 0.2 is considered random, values below are significant). ANOSIM global R evaluates whether there is a significant difference in species composition between two or more groups of sites. Stress values are goodness-of-fit statistics for NMDS. Contribution to dissimilarity between the sites was presented as percentage of contribution of each taxon to the overall dissimilarity (D) between the two ponds of different ages as quantified by the SIMPER routine (Clarke and Warwick 2001). The procedure calculates the ratio of the mean dissimilarity for all sample pairs between groups to standard deviation (SD) (mean D/SD[D]). This ratio indicates how consistently a taxon contributes to mean dissimilarity across all pairs and is a measure of the importance of each taxon in discriminating community composition at each sampling date (Clarke and Warwick 2001). 268 Southeastern Naturalist Vol. 11, No. 2 Results Physiochemical properties between the two sites remained relatively constant and were not significantly different, with the exception of winter and summer average temperatures (Table 1). Water temperature varied in winter around 11 °C in the 2-year and around 13 °C in the 30-year pond, while summer temperatures in both ponds were 20 °C higher. Acidity levels in the 2-year pond were lower (average pH 6.4) than in the 30-year pond (close to 7). All measured parameters indicated low nutrient and ionic composition. Both ponds had low concentrations of calcium and magnesium. Hardness remained below the standard (around 15 mg/L) in both ponds. Numbers of algal units varied more for the 2-year pond (mean = 1383, standard deviation = 621, range = 466–2328) compared to the 30-year pond (mean = 893, standard deviation = 216, range = 553–1124). Diverse species composition was documented for both ponds. Representatives of seven algal divisions were documented, and dominant algae belonged to Bacillariophyta or Chlorophyta. Species richness was equal or lower in the 2-year pond, with highest richness reported during summer in the 30-year pond (Fig. 2). A total of 81 species were identified in the 2-year pond, and 132 species were identified in the 30-year pond. The winter community differed in the two sites. The 2-year pond was dominated by filamentous green algae (Hyalotheca dissiliens and Mougeotia sp.) and coccoid algae, while the 30-year pond was dominated by chain-forming diatoms and filamentous green algae. At the beginning of summer, algal community in the 2-year pond was dominated by colonies of Tetraspora cf. cylindrica (Wahl) Agardh, while no other algae reached 20 percent relative abundance later in the Table 1. Physiochemical characteristics for the two locations, given mean ± S.E, all means not significantly different (P > 0.05) between the 2 ponds. Sample ID 2-year pond 30-year pond Winter Temp (°C) 10.9 ± 1.2 13.4 ± 1.9 pH 6.4 ± 0.5 7.2 ± 0.4 Summer Temp (°C) 29.3 ± 0.17 30.3 ± 1.00 pH 6.4 ± 0.11 6.7 ± 0.10 NO2-N + NO3-N ( μg/L) 4.4 ± 0.9 5.3 ± 2.0 NH4-N ( μg/L) 46.2 ± 15.70 48.4 ± 0.65 PO4-P ( μg/L) 1.50 ± 0.3 2.01 ± 1.3 Ca (mg/L) 1.56 ± 0.0 7.50 ± 5.8 Mg (mg/L) 0.81 ± 0.08 1.40 ± 0.50 Hardness (mg/L) 2.4 ± 0.08 8.9 ± 6.30 K (mg/L) 0.71 ± 0.23 0.90 ± 0.10 Na (mg/L) 0.95 ± 0.19 1.01 ± 0.20 Fe ( μg/L) 13.6 ± 9.2 50.5 ± 27.6 Cl (mg/L) 2.26 ± 0.46 2.27 ± 0.50 SO4 (mg/L) 7.12 ± 1.1 7.20 ± 1.2 fl( μg/L) 114.6 ± 1.9 133.7 ± 16.6 2012 J.N. Dominy, Jr. and K.M. Manoylov 269 summer. At this time, the community was dominated by long filaments of green algae and blue-green bacteria. The rarest alga reported from the 2-year pond’s summer samples are potential toxin-producing and bloom-forming blue-green bacteria (Fig. 3). Morphologically, Cylindrospermopsis raciborskii (Woloszynka) Seenaya & Subba Raju produced longer conical heterocytes and intercalary akinetes, sometimes two in a row (Figs. 3a–d). This is the first report for Georgia of the heterocyteproducing filament Richelia siamensis (Antarikanonda) Hindák (Fig. 3e), a species with undetermined ecology. At least one new species to science, of the genera Cylindrospermum, was documented in this study (Fig. 3f). Within the 30-year pond, all algae counts were dominated by chains of Fragilaria crotonensis Kitton and Fragilariforma sp. together with colonies of Tetraspora gelatinisa (Vaucher) Desvaux. In the 30-year pond, green filamentous algae such as species of Oedogonium and Desmidium swartzii Agardh, were found in large quantities during the winter months, whereas in the summer months, Cyanobacteria filaments like Oscillatoria princeps Vaucher and Nostoc sp. were dominate. The diatoms like Encyonema silesiacum (Bleisch) Mann, Craticula cuspidata (Kützing) Mann, Epithemia adnata (Kützing) Brébisson, and Rhopalodia gibba (Ehrenberg) Müller were found in small abundances. Filamentous green algae such as Spirogyra sp. and diverse coccoid members of Desmidiaceae were reported with representative species of Micrasterias, Closterium, Staurastrum, and Cosmarium present. A fairly rare green colony Gloeotaenium loitelsbergerianum Hansgirg was also documented. Overall, 21 species accounted for a total of 74.29 percent dissimilarity between the two ponds, with six of those species contributing at least 3 percent of the dissimilarity (Table 2). Twenty-eight percent (43 out of total 151 algal species observed) of the taxa observed carried 90 percent dissimilarity of the ponds. Two Figure 2. Species richness along sampling events: 2-year pond (striped bars) and 30-year pond (solid bars). Numbers coincide with the sampling events that took place: 1–3 in winter, 4–6 in summer. 270 Southeastern Naturalist Vol. 11, No. 2 species, Fragilaria crotonensis and Mougeotia sp. 2, contributed 12 percent and 9.3 percent, respectively, to the overall dissimilarity. The Shannon-Wiener diversity values for the 2-year pond had an overall average of 1.70, whereas the overall average diversity for the 30-year pond was 2.17. On average, the diversity was highest in the 30-year pond and lowest in the winter collection of the 2-year pond (Table 3). The 2-year pond community exhibited only slight variations in their cell algal community structure (max. diversity = 2.83; min = 0.88), whereas the 30-year pond community was closer to the predicted maximum biodiversity (Table 3). On average, the winter community was Figure 3. Heterocyteforming taxa from the 2-year recovery pond: a–d. Cylindrospermopsis raciborskii (Woloszynka) Seenaya & SubbaRaju, e. Richelia siamensis (Antarikanonda) Hindák, and f. Cylindrospermum sp. 2. Scale bar equal to 10 μm. 2012 J.N. Dominy, Jr. and K.M. Manoylov 271 lower in biodiversity and higher in evenness. Positive significant correlation between algal biodiversity and pond age was found for two of the summer sampling events (Fig. 4) Sampling date of specific community composition varied within the pond, with two to 19 similar taxa between the two ponds (24 total common for the two sites). This finding corresponded to lower average community similarity during summer collection compared to winter (winter mean = 0.3, range = 0.16 to 0.43; summer mean = 0.21, range = 0.10 to 0.34). The highest number of the same taxa composition (19) was recorded in the site with the highest species richness, yet similarity was only 34 percent. The lowest similarity reported was 10 percent for the last summer collection (Table 4). Community similarity for the two ponds was distinctly different based on total recorded algal composition and a low Jaccard index of 19.5 percent. Table 2. Average relative abundance (RA) of algal taxa that contributed more than one percent to the overall dissimilarity between 2-year and 30-year ponds recovering after kaolin extraction. The percent contribution (%D) of each taxon to overall dissimilarity (D) between the two ponds is shown; D/SD(D) is the ratio of the mean D for all sample pairs between pond types to the standard deviation of D and is a measure of the importance of each taxon in discriminating communities between pond types. Contribution (Con) of each taxon is given also and the cumulative percent (Cum%) is calculated. RA Taxon Group 30-y 2-y %D D/SD(D) Con Cum% Fragilaria crotonensis Kitton Diatoms 67.7 10.0 10.3 1.20 12.0 11.99 Mougeotia sp. 2 Green 2.8 48.8 8.0 0.98 9.3 21.31 Tetraspora gelatinosa (Vaucher) Desvaux Green 33.3 0.0 5.5 0.44 6.4 27.75 Hyalotheca dissiliens (Smith) Brébisson Green 2.8 27.0 4.5 0.74 5.2 32.99 Eunotia parallela Ehrenberg Diatoms 21.2 14.3 3.4 1.14 4.0 36.97 Fragilariforma sp. 1 Diatoms 18.3 0.0 3.0 0.44 3.5 40.50 Mougeotia sp. 1 Green 3.8 16.8 2.8 1.02 3.2 43.74 Tetraspora cf. cylindrica (Wahl) Agardh Green 0.0 16.3 2.7 0.44 3.2 46.92 Oedogonium sp. 2 Green 16.8 1.3 2.6 1.45 3.1 49.99 Navicula cryptotenella Lange-Bertalot Diatoms 2.3 17.3 2.6 1.01 3.0 53.03 Nitzschia dissipata (Kützing) Grunow Diatoms 0.8 16.3 2.6 1.18 3.0 56.00 Navicula trivialis var. oligotraphenta Diatoms 13.5 3.5 2.4 0.87 2.8 58.83 L-Bert. et Hofmann Achnanthidium minutissimum (Kützing) Diatoms 6.0 16.5 2.3 1.31 2.6 61.46 Czarnecki Oedogonium sp. 1 Green 8.7 2.0 1.6 0.58 1.9 63.35 Surirella tenera Gregory Diatoms 0.7 9.7 1.6 0.97 1.9 65.21 Frustulia krammeri Lange-Bertalot et Diatoms 1.3 9.7 1.5 0.87 1.8 67.00 Metzeltin Trachelomonas sp.1 Euglenoid 8.2 0.3 1.4 0.47 1.6 68.59 Stenopterobia delicatissma (Lewis) Diatoms 0.0 8.0 1.3 0.44 1.6 70.15 Brébisson Leptolyngbya sp. 1 Cyanophyta 5.2 9.7 1.3 1.3 1.5 71.61 Cryptomonas ovata Ehrenberg Cryptophyta 0.0 7.2 1.2 0.404 1.4 73.00 Synedra ulna (Nitzsch) Ehrenberg Diatoms 5.7 2.8 1.1 0.75 1.3 74.29 272 Southeastern Naturalist Vol. 11, No. 2 The ordination plot showed significant separation of the ponds based on years of recovery after kaolin removal, and this separation was independent of season (Fig. 5). The separation of ponds based on untransformed (ANOSIM Table 3. Community indices of ponds with two years and 30 years of development over two seasons with three replicas reported. H' = Shannon diversity, H' max = maximum Shannon diversity for each site, and J' =Evenness for units and cells. Pond Units Cells age Season Replica H' H' max J' H' H' max J' 2 Winter 1 1.78 2.56 0.69 1.61 2.56 0.63 2 Winter 2 2.06 3.22 0.64 1.16 3.22 0.36 2 Winter 3 2.71 3.30 0.82 2.14 3.30 0.65 2 Summer 1 2.63 3.78 0.69 0.88 3.78 0.23 2 Summer 2 2.64 3.33 0.79 2.46 3.33 0.74 2 Summer 3 2.64 3.00 0.88 1.97 3.00 0.66 30 Winter 1 1.34 2.30 0.58 1.68 2.30 0.73 30 Winter 2 1.66 3.26 0.51 1.44 3.26 0.44 30 Winter 3 2.36 3.43 0.69 2.23 3.43 0.65 30 Summer 1 3.19 4.22 0.76 2.94 4.22 0.70 30 Summer 2 3.17 4.09 0.77 2.64 4.09 0.64 30 Summer 3 1.47 3.09 0.48 2.07 3.09 0.67 Figure 4. Regression analysis of Shannon diversity change for the 2-year and 30-year ponds. 2012 J.N. Dominy, Jr. and K.M. Manoylov 273 global R2 = 0.65, NMDS stress = 0.11,) and square root transformed data (ANOSIM global R2 = 0.48, NMDS stress = 0.1) was significant. Separation was based on presence-absence of taxa in one pond or another and not simply a result of differences in relative abundance. Discussion Biodiversity was lower for the 2-year pond, and the algal community experienced potential turnover from filamentous green algae to filamentous blue-green bacteria for both sites. Toxin-producing cyanobacteria, Cylindrospermopsis rociborskii, and members of the genus Cylindrospermum were observed during analysis only in the summer samples in the 2-year pond; however, the concentrations found were too low for bloom formation. Biodiversity for the 30-year pond remained significantly higher during both seasons. Findings of this study suggest Figure 5. Nonmetric multidimensional scaling ordination plot of algal communities from the 2-year and 30-year ponds in Georgia based on Bray-Curtis dissimilarity and presenceabsence of square-root transformed data: winter (w) and summer (s). Table 4. Sǿrensen Similarity (S) presented as percent similarity of the 2 ponds collected on the same date. Numbers coincide with the sampling events that took place: 1–3 in winter, 4–6 in summer. Season Sample Similar species S Winter 1 5 0.43 Winter 2 4 0.16 Winter 3 9 0.31 Summer 4 19 0.34 Summer 5 9 0.20 Summer 6 2 0.10 274 Southeastern Naturalist Vol. 11, No. 2 that the 30-year pond can be used as an ecological benchmark for implications referring to an ecological, stabilized aquatic system after mining processes have ceased. Identification of high-value ecological benchmarks has been reported as a high priority for aquatic science (Hawkins et al. 2010). A thirty-year time period of development has been reported as a good benchmark of stability in terrestrial communities (Baeten et al. 2010). Diverse algal communities increase the stability of an area and therefore the overall health of an ecosystem. Similar to other research on small ponds (Sheavly and Marshal 1989), biodiversity of the ecosystem recovering from kaolin extraction increased with time. Dominant green filamentous algae from genera like Mougeotia, and Hyalotheca were observed during winter months as large amounts of algal units and may suggest mesotrophic conditions. Mougeotia can form substantial sub-surface growths in acidified waters and is widely regarded as an indicator of early environmental change (Turner et al. 1991). In the 2-year pond, pH was consistently lower, but both ponds had very diverse representativeness of Desmidiaceae. Other green filaments were represented with few very long filaments and comprised a large portion of the cell counts. Results from this study suggest that after two years of pond reclamation, environmental conditions allowed for the development of a diverse algal community. It was found that for both sites, as the overall water temperature increased, there was an increase in algal diversity and abundance. This finding was to be expected since green algae and Cyanobacteria prefer warmer conditions and increased sunlight (Stevenson 1996). Abundant algae from the winter sampling event in the 2-year pond were not observed in consecutive sampling events, documenting dynamic changes in the algal community composition. Our results are a snapshot of the algal community development under similar environmental conditions in ponds of different age, and we are not addressing short-term successional changes through time. High diversity documented in this study is similar to other diverse algal communities developed in low-nutrient clay pits in urban areas (Schagerl et al. 2010). The primary mechanism driving these relationships was a dominance (or selection) effect: more diverse communities were more likely to contain the most productive and least prone to invasion types of algae. Low evenness due to dominant species can produce a negative relationship between species diversity and ecosystem function (Creed et al. 2009). Regardless of the extensive observation in the 30-year pond, summer toxin-producing Cylindrospermopsis rociborskii representatives were not documented. The highest relative abundance recorded in this study in 30-year summer samples (Fragilaria crotonensis chains or Tetraspora colonies) both corresponded to different measures on the units and cell diversity and evenness metric. Algal taxonomy and biology is an important contributing factor for the diverse responses in kaolin recovery ponds. Decrease in available nitrogen together with high water temperature (Nydick et al. 2004) will lead to an increase in Cyanobacteria (Blue-green algae) with heterocytes. This result was observed in the 2-year pond summer sampling. Observations at the 2-year pond, where constant runoff of sediment was not 2012 J.N. Dominy, Jr. and K.M. Manoylov 275 buffered, might provide an explanation of increased turbidity and high availability of clay particles. The 30-year site is surrounded by well-established meadow, forested area, and no agricultural activities, so observation of the low nutrient algal taxa was not surprising. There are no urban areas or agricultural activities in the immediate surroundings of both ponds. Analyses of nutrient content among sites were conducted during the summer months. When comparisons were analyzed between both sites, nutrient availability seems to have played an insignificant role in determination of species richness between the two locations. Cyanobacteria possess nitrogen-fixing heterocytes, which allow them to thrive in conditions when nitrogen levels are low and thus unfavorable for green filamentous algae. Chemical analyses during the summer months revealed that distinctions between the two sites’ abundance and diversity values of the algal species were not affected by nutrient concentrations. Studies performed on terrestrial plants when examining the effect on resource availability has shown that an increase in nutrients will enhance biodiversity effects within an area (Jonsson and Malmqvist 2003). However, it has also been recognized that within algal communities species richness may be independent of nutrient availability, and the effect of species richness on the temporal variability of community was neutral only in nutrient-rich environments, while a stabilizing effect of diversity was found in oligotrophic environments (Zhang and Zhang 2006). Both kaolin recovery ponds were considered nutrient-poor and presented a good opportunity to compare algal community alterations over short and long periods of time. One possible explanation of the high diversity found within the 30-year site could be correlated to the “niche complementarity effect” (Zhang and Zhang 2006). This effect explains how resource partitioning within a stabilized aquatic system may overcome the results of temporal change in an environment and would explain the higher community diversity and species richness found within the 30-year site in comparison to the 2-year site, as well as the documented appearance of potentially bloom-forming blue-green algae during the summer months in the 2-year pond. Longer-term development of aquatic systems with minimum anthropogenic influence can lead to system-wide stability even for newly created aquatic habitats after destructive human practices. 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