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Determination of Primary Placeholder Habitat Associations in a Kelp Forest Ecosystem through UPC Analysis [[3/4 clear indication of the study system, but doesn’t hint at the larger ecological questions]] Ian Moffitt [[9/14 - Overall Clarity – line-by-line edits provided for the intro only, try to apply these concepts to the rest of the paper and consider in your future work. Don’t use jargon, where a simpler word would achieve the same thing, and definitely don’t use any words if you don’t understand what they mean! Make sure each sentence has a clear subject and a verb (i.e. a PERSON/THING that is DOING something) to avoid passive voice and make your writing easy to understand. Carefully review rules of punctuation and learn how to use commas, colons, and semi-colons correctly. Carefully choose your connecting words (e.g. whereas, while, however, in contrast, thus) so that they are appropriate to the sentence, because each of these words means something slightly different. Read your sentences out loud to yourself (you’ll only look a little crazy) to make sure that they flow naturally and are not broken into too many unnecessary clauses; if they don’t flow naturally try reordering the clauses/ ideas. Try varying sentence length for a mixture of longer sentences that connect multiple concepts and short sentences that make a single clear point. Don’t forget to connect the dots between ideas, just because you understand how two ideas presented in adjacent sentences are related, does not mean it’s clear to your reader. Call on your classmates to proof read for you! They can help identify where your writing is unclear so that you can fix it BEFORE you turn your paper in! Abstract: [[no abstract was required for this assignment. A true abstract should summarize the whole paper including key questions, context, methods, results, and conclusions]] UPC transects were performed at Hopkins Marine Station to quantify the occurrences of different substrate types, relief types, and species associations with both of these habitat characteristics. This was done in an attempt to understand how niche partitioning can attribute to the maintenance of the biodiversity found in the kelp forest ecosystem. Introduction: [[10/20 This introduction could be improved by: 1) beginning with the big ecological question, how diversity is maintained in the face of interspecific competition, and using the scientific literature to create the context for this question, 2) identifying how this study addresses questions about niche diversification and partitioning, 3) introducing the clear and specific questions this study was designed to address and their associated hypotheses (in paragraph format), and 4) addressing why your study is novel and adds to the field of ecology.]] Kelp forest ecosystem structure is [[dynamics are about changes through time]] thought to be affected by species [[primary placeholder is an awkward phrase that doesn’t make a lot of sense out of context]] associations with different geological factors, such as substrate and relief type. These associations vary in strength and may form the basis for inter-specific interactions that form the complex trophic web of the kelp forest. Associations between benthic habitat characteristics and sessile organisms are important to understand because they help to explain the incredible amount of diversity found in the kelp forest ecosystem as established through niche partitioning. [[you should be using citations in this section. A better introductory paragraph would start by explaining broader ecological context (with citations) and why we care to understand the factors that maintain diversity in the face of competition. Then you can describe how specieshabitat associations help us examine niche diversification]] UPC [[need to spell out uniform point contact]] transects were performed at Hopkins Marine Station to analyze species-habitat associations with respect to substrate and relief in the kelp forest ecosystem. Depending on the relative proportion of each type, species associations were statistically determined to strongly correlate, moderately correlate, or weakly correlate to these geologic features. Strongly positive correlations between geologic features and primary placeholder type can be used to evaluate niche diversification in that certain species are found to occur there more often than would be expected by chance, indicating that they have adapted to survive better than other organisms in that area. If two organisms are found to exhibit strong associations with the same type of habitat, there is a possibility that the organisms are competing for space. Strongly negative correlations are important in that they suggest a particular primary placeholder is either incapable of surviving in a habitat or was outcompeted by another species in the past (Watanabe 1983). [[This is a great explanation of how results can be interpreted, but it doesn’t really belong in the introduction.]] We hope to identify different patterns of species-substrate associations that suggest niche partitioning to help explain how the diversity of species in the kelp forest is maintained. Hopkins is an ideal location to test this hypothesis because it is located in a no-take marine reserve that frees it from most anthropogenic influences that could bias the data. There is also a large amount of primary placeholder diversity as well as ample variation in substrate and relief type. Methods: [[8/18 - The methods section should begin by briefly describing the general approach (observational, UPC method to characterize primary substrate holders, substrate type, and relief). Then talk about the system and expand on why it’s a good site for this study (something that should be introduced in the intro). Then you need to identify the specific hypotheses and explain how your data collection methods will allow you to test each hypothesis. After you’ve explained WHY you did things the way you did, you want to provide a detailed description of methods, including data analysis..]] Site: We conducted a UPC survey at Hopkins Marine Station (36º36’N, 121º54’W) of Stanford University. The geology of the site is ideal for determining species associations with different habitats. Large granitic outcrops in shallow water give rise to moderate and high relief bedrock surrounded by sand flats in deeper water (Watanabe 1983). The survey was conducted on April 10, 2012 in the morning when the weather was overcast, in-water visibility was about 5 meters, and the conditions were placid. The tide was very low (-0.87 ft) which contributed to a depth range of seven to ten meters. [[could explain a little more clearly WHY the characteristics of this site are good for this kind of study]] Approach: [[start with the more general approach and why it is suited to answering your questions, then link specific methods to each of your hypotheses and explain how they’ll allow you to test thos hypotheses before you launch into all the details]] The UPC transects were conducted by ten buddy pairs using SCUBA along the permanent transect cable from 90-135 meters. Each buddy team collected 120 data points for a total of 1,200 [[good to have total number of data points!]]. The uniform points were picked to occur at every half meter along a 30 meter transect performed on and off shore (270, 90 degrees respectively). Transects were split in half by each group composed of a buddy team, so one person was always 2.5 meters in front of the other. The substrate and primary placeholder was determined indiscriminately as the object located directly underneath the previously determined uniform point along the transect. Relief was recorded by determining the maximum height change in a .5/.5 meter window of the uniform data point. Four types of substrate were differentiated as sand, cobble (<10 cm), boulder (10cm-1m), and bedrock (>1m). Four classifications of relief were differentiated as flat (0-10 cm), slight (10cm-1m), moderate (1-2m), and high (>2m). The primary placeholders that were counted are referred to in Figure 1. Figure 1 [[ I like the table to list species]] Inanimate Red Algae Coralline Brown Algae Tube Worms Bare rock Branched Crustose Cystoseira Solitary osmundacia tubeworm Dictyoneurum Diopatra ornata Bare sand Leafy Articulated californicum Shell debris Bushy ------------------ Egregia Phragmatopoma menziesii californica Sediment Lacy ------------------ Desmarestia Dodecaceria spp Dead Encrusting ------------------ Macrocystis -------------------- holdfast red ---------------- Turf holdfast ------------------ Laminariales -------------------- holdfast ----------------- ------------------ ------------------ Dictyotales -------------------- spp. Snails Cnidarians Tunicates Other Serpulorbis Corynactis Colonial tunicate Scallop squamigerus californica Petalochonchus Cup coral Solitary tunicate Embedded monteryensis cucumber ----------------------- Other anemone ------------------------- Barnacle ----------------------- Hydroids ------------------------- Bryozoan ----------------------- Stylaster ------------------------- Sponge californica ----------------------- -------------------------- ------------------------- Mussel Species-Habitat associations The substrate and relief data were combined with the species data to determine a standardized measure for the deviation from substrate-species and relief-species associations expected by chance. The values obtained take into consideration the total occurrence of a particular type of substrate and use that as the “expected” level of species association. Deviations from this “expected” value that are >2 or <-2 are considered to be strong associations, deviations <2 and >1 or >-2 and <-1 are considered moderate, and all other deviations are considered weak. Only strong associations were considered in this study to determine if specieshabitat interactions were occurring in the ecosystem. Results: [[7/16 - would be improved by inclusion of: 1) general results (from first two graph pages that Pete presented, 2) description of the results relative to each hypothesis including whether associations were positive or negative and whether or not the results supported your hypotheses, and 3) inclusion of more figures and better figure formatting (try using a 1x2 table for your figures with the actual figure/table in one cell and the caption in the other an combine all the figures into a single section, either within the results section or at the end of the paper to avoid formatting problems and interrupted flow)]] Substrate and Relief We found that the substrate was composed of 40% sand, 6% cobble, 20% boulder, and 34% bedrock. 42% of the relief type was slight, 40% was flat, 14% was moderate and 6% was high. Most of the flat relief was associated with the sandy substrate while the slight, moderate, and high reliefs were associated with the bedrock and boulder substrates. [[good general results]] Species Associations with Relief [[good to organize by hypothesis, but you need more details here!!]] Eleven primary substrate holders exhibited strong interactions with the four levels of relief (See Figure 2). [[you should describe some of these in the text]] Species Associations with Substrate Eighteen primary substrate holders exhibited strong interactions with the four substrate types (See Figure 3) [[you should describe some of these in the text]] Figure 2 Figure 3 Figure 2 represents the deviation from expected values of 4 types of relief with respect to species associations. From left to right the order of relief is: flat, slight, moderate, and high Figure 3 represents the deviation from expected values of four types of substrate with respect to species associations. From left to right the order of substrate is: sand, cobble, boulder, and bedrock. Discussion: [[13/22 – You did a good job of tying the discussion back to the big ecological questions introduced in the introduction, and a fairly good job of summarizing the results and interpreting them, including possible mechanisms for the species- habitat associations you observed (both why they exist and how they’re maintained). However, to improve the discussion, you should: 1) more clearly address whether or not your results support your hypotheses, including problems with your study design that may have influenced your results, and 2) use the scientific literature to provide context for your results (i.e. compare to previous similar studies including AT LEAST 2-4 citations in the discussion, not all of them from readings and lectures!)]]. The strong associations of certain primary placeholders to specific types of relief and substrate compel us to ask why and how they occur in higher densities on these particular habitats. An analysis of why the strong associations between species and habitat type occur allows us to better understand the mechanism through which the biodiversity in the region is maintained. Furthermore, understanding how different benthic species interact in close proximity to one another, gives us insight into how these organisms may have evolved and how they are still evolving through competitive interactions to better adapt to a niche. Species Interactions with substrate Articulated coralline algae spores recruit best to boulder substrates (Figure 3) (http://www.mbari.org/staff/conn/botany/reds/ian/artcor/ecology.htm) Although the articulated coralline did exhibit a positive association to bedrock as well, it did not exhibit a strongly positive association (Not shown in results). This could have been due to error in the sampling as it is somewhat difficult to distinguish between the different types of red algae, or it could be indicative of strong competition for space on bedrock, causing the competitive exclusion of articulated coralline spore recruits. Its strong associations with moderate relief (see results) confirm its preference for boulders and bedrock (it was found that boulders and bedrock are typically moderate to high relief) and further suggest that it cannot recruit to sandy substrate. Indeed, all of the red algae recorded for this survey, exhibited negative associations with sand except for the lacy reds (see Figure 3). Interestingly, the branching, crustose, and encrusting red algae co-occurred on bedrock while the articulated, branching, bushy, and leafy coralline algae co-occurred on boulders. Since all of these associations are strong, it is quite possible the algae that spatially co-occurs is competing for space, or recruiting to a unique microscopic cue on the substrate. The red algae that associates independently (crustose and encrusting red are distinct from articulated, bushy, and leafy) has most likely already undergone competitive interactions in the past leading to niche diversification. Furthermore, it should be noted that the branching reds may exhibit competitive superiority or have less specific recruitment cues, in that they strongly associate to both boulder and bedrock substrate. The strongly positive association of cup coral to bedrock and high relief reflects its preference for rocky areas exposed to more water flow that provide better feeding conditions, but may also be indicative of the larval dispersal of the organism. Cup corals (specifically Balanophyllia elegans) do not have larvae that disperse long distances (Altieri 2003). The larvae crawl along the substrate and usually do not disperse more than 1.3 meters away from the parent individual (Altieri 2003). From an ecological standpoint, this suggests that if one individual is able to colonize a rock, soon many individuals will colonize any free space on that rock, leading to very high population densities in isolated areas. Another colonial Anthozoan known as Corynactis californica was observed to occupy a very similar niche. This suggests that some competitive interactions may currently be taking place between the two species (Chadwick 1991). Another potential for competitive interactions can be seen in the strong positive associations of both barnacles and colonial tunicates to bedrock and high relief (see results). It has been noticed that colonial tunicates (particularly Didemnum spp.) often grow over barnacles at Hopkins (Kim, Zarri personal communication). These organisms may be undergoing competitive interactions that could lead to niche partitioning over evolutionary time. The findings of this study show that there are patterns of association between substrate/relief type and different primary placeholder species. Strong, positive habitat associations among different species suggest competitive interactions are taking place to establish niche partitioning. Strong, negative associations show that an organism is incapable of colonizing an area because of its own recruitment limitations or because it was outcompeted evolutionarily. It is important to understand the habitat associations of primary placeholders if one is to understand how and why the amount of biodiversity present in the kelp forest ecosystem can be maintained. Citations: [4/6 – at LEAST 6 references were required for this assignment and please review guidance on formatting references!]] Altieri, A.H.2003. Settlement cues in the locally dispersing temperate cup coral Balanophyllia elegans. Biological Journal 204: 241-245 Chadwick,N.E.1991. Spatial distribution and the effects of competition on some temperate Scleractinia and Corallimorpharia. Marine Ecology Progress Series 70: 39-48 Ehrenreich, I.2001 http://www.mbari.org/staff/conn/botany/reds/ian/artcor/ecology.htm Watanabe,J.M.1984. The influence of recruitment, competition, and benthic predation on spatial distributions of three species of kelp forest gastropods(Trochidae: Tegula)