Review: Amphibian ecology paper

[Alyrium Denryle]

The Effect of Wetland Hydroperiod and Upland Habitat Structure on Amphibian Metacommunities: A Review
By Benjamin Allen

Amphibians which use aquatic breeding modes, particularly the Ranidae, have been used as model systems in ecology since the 1960s (McDairmid and Altig 1999). Their complex life cycles allow them to be used to study evolutionary and ecological processes such as predator-prey interactions (Formanowicz. 1978; Formanowicz 1986; Brodie and Formanowicz 1987; Pearl, Adams et al. 2003), competition (Griffiths, Edgar et al. 1991; Bardsley and Beebee 2000; Relyea 2002), and metapopulation dynamics (Van Buskirk and McCollum 2000; Marsh 2001; Petranka 2007). It is also this complex life cycle that makes them ideal organisms for examining the interdependency of wetlands and the surrounding upland areas. This is because aquatically breeding amphibians are linked directly to both due to their terrestrial habitat use and dispersal, and their aquatic reproduction (Petranka 2007). Unfortunately amphibians are currently in a world-wide decline (Collins and Storfer 2003). Understanding amphibian metapopulations and the conditions that structure amphibian communities is of paramount importance if we are to conserve the species which remain. Their fate may also serve as harbinger for what will occur to wetland ecosystems and the organisms which dwell in them as a whole. The following review details the importance of upland habitat and wetland hydroperiod in determining the persistence and metapopulation dynamics of species within wetland anuran communities.

Amphibian metapopulation dynamics have often been viewed as a “ponds as patches” model (Marsh 2001) where breeding locations are used to delineate sub-populations that exchange migrants and define the units in which local extinction and colonization occur. However, many amphibians have short maximum dispersal distances (Smith and Green 2005) and the actual distribution of amphibian dispersal is log-normal. This means that most amphibians are site loyal but there are occasional long range dispersers. These individuals would be heavily impacted by the terrestrial habitat between wetland sites. It is possible to assess how upland habitat structure affects species composition and community structure. This can be done in several ways. The first is to use observed or experimentally manipulated changes in the makeup of terrestrial habitat to determine the effect on particular populations. The other is to examine species richness and composition across a gradient of habitat fragmentation, or habitat composition.

Lithobates sylvaticus, the wood frog, is a common subject for both observational studies of populations and in experimental manipulation (Patrick, Harper et al. 2008; Windmiller, Homan et al. 2008) A particularly good example is the work done by Windmiller et al (2008). They evaluated the effects of urban development on a series of vernal pools in Massachusetts on wood frogs (L. sylvaticus) and Ambystomatid salamanders (Windmiller, Homan et al. 2008). They found massive and sudden population declines in all three species, including the near-extirpation of L. sylvaticus from one of the ponds. This decline persisted for at least a two year period post construction and may have been mediated by direct mortality of adults and the resulting lack of recruitment.

This mechanism has experimental support as well. In work done by Patrick et. al. (2008), newly metamorphosed frogs selected experimentally manipulated habitat at a coarse grain of 2.2 ha forest treatments. They showed no preference for fine grained patches of suitable habitat during dispersal, but displayed it once they were settled into area at a scale of 2-4 square meters. This, combined with a lack of density-dependent habitat selection, resulted in small patches of habitat with very high numbers of frogs. The high densities lead to extremely high mortality in the population. This is particularly important because it has been shown in some Ranids, particularly Lithobates castesbeianus, that the most important life history stage for structuring amphibian populations are the number of metamorphs that leave the pond successfully (Govindarajulu, Altwegg et al. 2005). High mortality in the metamorph stage has the potential to cause population collapses and in the more terrestrial amphibians such as L. sylvaticus, result in extirpation in what once may have been a source habitat within the regional metacommunity.

So what does this do when applied across a region with multiple species? The results vary somewhat depending on what measures are used to assess amphibian diversity (Knutson, Sauer et al. 1999; Guerry and Hunter 2002; Pillsbury and Miller 2008; Babbitt, Baber et al. 2009). Knutson et al (1999) found that amphibian species richness was positively associated with both forested and agricultural habitat, as well as with areas of forest-agricultural edge. This work is in agreement with Guerry and Hunter (2002) who showed that amphibians have particular preferences for open habitat, forested habitat, and to some degree on the adjacency of ponds to forested habitat. In this context an area which has a patchy mosaic of open and forested habitat will contain more species than a more homogenous landscape.
However, Guerry and Hunter (2002) did not classify agricultural habitat and naturally occurring habitat differently. Certain processes that occur on agricultural lands have been shown to have devastating impacts on amphibian recruitment (Davidson 2004; Relyea 2009; Relyea 2009; Relyea and Jones 2009). Pesticides often act as endocrine disruptors (though others as neurotoxins) and have been found to sex-reverse genetically male frogs (Hayes, Collins et al. 2002; Hayes 2004). They have also been shown to the following effects: increase the time to metamorphosis and thus increases desiccation risk (Hayes, Case et al. 2006; Marquez-Garcia, Correa-Solis et al. 2009), decrease size at metamorphosis (Hayes, Case et al. 2006), depress the immune system (Rohr, Raffel et al. 2008) and increase the risk of mortality by predation by disrupting their ability to effectively respond to predators(Relyea 2009; Relyea 2009; Relyea and Jones 2009). In addition to pesticides, nitrogen fertilizers have also been shown to negatively impact larval amphibians (Griffis-Kyle and Ritchie 2007). Given these results, one would not expect to see amphibians present, let alone positively associated with these locations.

The discrepancy may be explained by sampling method. Both of these studies used amphibian call surveys to detect the presence of amphibians. These surveys indicate that adults are present and attempting to breed, however they do nothing to indicate the success of those reproductive attempts. These agricultural areas may act as population sinks (Rowe, Hopkins et al. 2001), where adults migrate through suitable terrestrial habitat from suitable breeding habitat and fail to locally recruit new individuals into the population sufficient to replace losses. This makes the population continually reliant on new immigrants. This however, would not be detected by a call survey.

In a larval survey amphibian species richness is similar in wetlands surrounded by woodlands, prairies, and rangeland, however it is significantly reduced in pasture(Babbitt, Baber et al. 2009). Additionally, mean abundance is highest in wetlands surrounded by forest, and lower elsewhere, particularly in range and pasture land, but in natural prairie as well. These results indicate that simply measuring presence is insufficient evidence to conclude that a population is doing well, but rather the abundance of species which are present needs to be taken into account as well. This is especially true with animals that may disperse between possible breeding areas. It also shows a distinct difference between the use of larval surveys and the call surveys found in Knutson et al (1999). In all of these cases, a call survey would not have detected the decreased larval abundance and thus recruitment in these populations and it may have detected non-breeding but present species.

For urban-rural gradients the results are unequivocal. Conversion of upland habitat to human habitation is negatively associated with amphibian species richness (Parris 2006; Gagne and Fahrig 2007; Egan and Paton 2008; Pillsbury and Miller 2008; Randhir and Ekness 2009). In cases where this relationship is examined more closely, not only is the upland habitat affected, but so are the wetlands themselves. Hydroperiods often shift(Rubbo and Kiesecker 2005) and wetland hydroperiods act as a filter for amphibian species(Skelly 2001). This species filter is not only a direct effect of the hydroperiod through desiccation risk (Rowe and Dunson 1995; Bridges 2002) but also indirectly through mediating predation risk (Lardner 2000).

In unmodified systems, if hydroperiod is short species composition will be biased in favor of species which exhibit the ability to metamorphose quickly. They need to get out of the pond before it dries. One would expect that both exploitative and interference competition should be very strong in these communities, and that this should be done in preference to exhibiting anti-predator mechanisms which pose a cost to development time (Anholt, Skelly et al. 1996; Lardner 2000; Relyea 2002) . This has been found in the genus Pseudacris (Skelly 1995), where Pseudacris trisceriata inhabits temporary ponds and under experimental and field conditions reaches metamorphosis much faster than Pseudacris crucifer which breeds in more permanent water. In this same system it was found that this difference is mediated by foraging behavior and activity level (Skelly 1995) and is the result of a trade-off between anti-predator behavior and growth. Reduced activity reduces the risk of predation, but also limits the amount of time the tadpole spends foraging. Activity level in this system is known to have this effect because it has been experimentally manipulated by tricaine anesthesia (Skelly 1994). Lithobates sylvaticus tadopoles were either left as controls or anesthetized with Tricaine and both groups were exposed to larval dragonflies in the genus Anax. The sharp decrease in activity was associated with an equivalently sharp drop in predation-mediated mortality.

Relative activity level has also been shown to mediate interspecific exploitative competition in a Lithobates sylvaticus-Lithobates pipiens competitive system (wood frogs and leopard frogs respectively). It was found that under field conditions, Lithobates sylvaticus fares better in competition with L pipiens. So well in fact that they depress growth in the leopard frogs without themselves having their growth depressed (Relyea 2000). With the addition of predator cues from caged invertebrate and fish predators however the effect was reversed and the leopard frogs asymmetrically depressed wood frog growth. In the laboratory component of this experiment it was shown that wood frogs were consistently more active than leopard frogs, even when exposed to invertebrate predators. They were no differences between species when exposed to fish, because in the field neither of them typically breeds in water containing fish. This was enough for leopard frogs, perhaps with the addition of predator or competitor-induced morphological (Relyea 2002)shifts to reverse the asymmetry of competitive interactions. It was also found that changes in morphology that grant anti-predator advantages in wood frogs are the opposite of changes that enhance competitive ability (Relyea 2002). This probably mediates the interaction between wood frogs and leopard frogs observed.

These anti-predator mechanisms are often phenotypically plastic, where one genotype dictates multiple phenotypes that are dependent on environmental context. Plastic phenotypes tend to evolve when an organism is subject to a temporally or spatially variable environment (Relyea ; Van Buskirk, McCollum et al. 1997; Schoeppner and Relyea 2009).
Anti--predator mechanisms have the opposite relationship to hydroperiod that competitive mechanisms do, just as it has inverse effects on morphological phenotype (Lardner 2000). Amphibians which breed in temporary water where predation risk is predictably low not only tend to lack constitutive morphological defenses, they also do not exhibit morphological defenses induced by predation. Those that breed in spatiotemporally variable water bodies tended to display plastic phenotypes, while those which breed exclusively in permanent water exhibit stronger constitutive defenses (Lardner 2000; Jara and Perotti 2009). It has been shown the behavioral phenotypes tend to be more plastic than morphology (Relyea 2001). When this was subject to an exhaustive survey in North American and Eurasian anurans, it was found that while morphological plasticity was significantly related to the spatiotemporal variability in hydroperiod and thus predation risk, behavioral plasticity was not (Van Buskirk 2002). This may indicate that the costs of behavioral plasticity may be lower than the costs of morphological plasticity, probably because behavioral changes can respond to moment-by-moment changes in predation risk(Van Buskirk and Arioli 2002; Peacor 2006), while morphological changes are not as easily reversed (Van Buskirk 2002). Amphibians also appear to evaluate predation risk and respond in a way which is proportionate to that risk, rather than the responses being determined based on some sort of risk-threshold (Anholt, Skelly et al. 1996; Murray, Roth et al. 2004).

Given that this is the case, do these mechanisms which are seen in the lab have the predicted effect in the field? What would be predicted is that amphibians which have short larval periods would be excluded from areas where hydroperiods are more permanent, because they lack the ability to deal with both the predators present in permanent water bodies and cannot compete with those that can. This has been shown repeatedly in the literature (Skelly, Werner et al. 1999; Baber 2004; Cunningham, Calhoun et al. 2007). The converse is also true, but for different reasons. Short hydroperiods exclude amphibians with long development times due to whole clutch mortality prior to metamorphosis, though temporary water can be used as foraging habitat or as a corridor for dispersal (Cook and Jennings 2007). However, some of these effects may be obscured due to differences in sampling techniques, some of which are unsuitable for detecting successful reproduction (Knutson, Sauer et al. 1999; Guerry and Hunter 2002; Babbitt, Baber et al. 2009).

It should be clear from this review that both upland habitat and wetland habitat are essential for maintaining amphibian species richness and abundance within a region(Cunningham, Calhoun et al. 2007; Babbitt, Baber et al. 2009). Maintaining a complex mosaic of open and wooded upland habitat, as well as maintaining natural spatiotemporal variability in wetland hydroperiods will allow more species to persist within a region than would if degraded, only be able to support a subset of the regional species pool(Herrmann, Babbitt et al. 2005). Upland habitat provides dispersal corridors as well as foraging and overwintering sites for metamorphosed amphibians (Funk, Greene et al. 2005; Patrick, Harper et al. 2008). It is essential for maintaining an age structure that is conducive to species persistence(Govindarajulu, Altwegg et al. 2005), and for maintaining the interconnectivity of metapopulations (Greenwald, Purrenhage et al. 2009). The effects of hydroperiod are mediated by the interaction between interspecific competition and predation risk(Relyea 2004; Werner, Skelly et al. 2007), and directly impacts recruitment into the population. Not only is this useful for understanding ecological and evolutionary processes, but it also serves as a cautionary tale. Humans have been modifying the habitat upon which amphibians depend (Egan and Paton 2008; Windmiller, Homan et al. 2008; Baldwin and Demaynadier 2009). It has been done for housing, agriculture, mineral extraction, flood control, storm water retention and many other purposes. However this is having a negative impact on amphibian populations, and due to the status of amphibians as bioindicators (Beebee and Griffiths 2005), and their current mass-decline (Collins and Storfer 2003) we have legitimate cause for concern.


Citations
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Herpetology. J. C. Mitchell, R. E. J. Brown and B. Bartholemew. Salt Lake, SSAR: 41-53.

[Lagmonster]

Changed the title. The typo wasn't enough; I had to make it clearer as well.

And yes, your dedication to herpetology is admirable, although your personal concern for actual animals is bizarre and rubs a shy left of Goodall. Doubtless you hold firmly to the idea that amphibians are the 'canaries in the mineshaft' when it comes to indicators of environmental health?

[Alyrium Denryle]

Changed the title. The typo wasn't enough; I had to make it clearer as well.

And yes, your dedication to herpetology is admirable, although your personal concern for actual animals is bizarre and rubs a shy left of Goodall. Doubtless you hold firmly to the idea that amphibians are the 'canaries in the mineshaft' when it comes to indicators of environmental health?

Pretty much. Amphibians, because of their moist permeable skin and complex life cycles are particularly good indicators of environmental health. Even the ones that breed terrestrially are still dependent on moisture and can be impacted by airborn contaminants. When you have created a situation where a third to half of them (depending on the estimate) are dying off you have a problem.

Also: I fail to see why I would not have concern for other organisms. They exist for their own sake, as beings that on some level experience their own lives. Why on earth should they not be worthy of moral consideration?

[Ziggy Stardust]

I don't quite understand the relevance of the anti-predator mechanisms to the rest of the paper, interesting though it may be. What exactly is the relationship between these mechanisms and the hydroperiod discussion?

[Anguirus]

I swear I will get to this, Alyrium. But it might be next week. >_<

[Alyrium Denryle]

I don't quite understand the relevance of the anti-predator mechanisms to the rest of the paper, interesting though it may be. What exactly is the relationship between these mechanisms and the hydroperiod discussion?

In unmodified systems, if hydroperiod is short species composition will be biased in favor of species which exhibit the ability to metamorphose quickly. They need to get out of the pond before it dries. One would expect that both exploitative and interference competition should be very strong in these communities, and that this should be done in preference to exhibiting anti-predator mechanisms which pose a cost to development time (Anholt, Skelly et al. 1996; Lardner 2000; Relyea 2002) .

These anti-predator mechanisms are often phenotypically plastic, where one genotype dictates multiple phenotypes that are dependent on environmental context. Plastic phenotypes tend to evolve when an organism is subject to a temporally or spatially variable environment (Relyea ; Van Buskirk, McCollum et al. 1997; Schoeppner and Relyea 2009).
Anti--predator mechanisms have the opposite relationship to hydroperiod that competitive mechanisms do, just as it has inverse effects on morphological phenotype (Lardner 2000). Amphibians which breed in temporary water where predation risk is predictably low not only tend to lack constitutive morphological defenses, they also do not exhibit morphological defenses induced by predation. Those that breed in spatiotemporally variable water bodies tended to display plastic phenotypes, while those which breed exclusively in permanent water exhibit stronger constitutive defenses (Lardner 2000; Jara and Perotti 2009).

I hope that answers the question. Amphibians display anti-predator mechanisms that reflect a tradeoff between being able to leave a pond before it dries up and they die, and being able to respond effectively to predation risk.

[The Episiarch]

Just a few comments/questions:

1) What type of journal are you submitting this to, is it a herp-type journal (e.g: Herpetological Review, Herpetological Journal, etc), an ecological journal (Oecologia, Evolutionary Ecology, etc) or a conservation biology journal (Animal Conservation, Conservation Biology, etc) as it would affect what emphasis you how you pitch this paper. It won't change the overall content but it will affect how you write your intro.

2) I liked your synthesis of anti-predator response/mechanism, but the way it appeared in your MS seems slightly abrupt. Maybe there's a way you can ease it in to place it better into the wider context of everything you were discussing before that.

3) On the subject of anti-predator response/mechanism, maybe you should also touch up the effect of infectious diseases. I noticed you cited one of the Rohr paper, but currently there's a lot of work done on infectious diseases of amphibians especially in the high competitive field of amphibian chytridiomycosis. There as been some work done on the effect of trematode infection on amphibian ecology, but currently trematode research isn't as sexy as chytrid research, so most of what you find on that will be related to chytrid. Like anti-predation response, there are evidence to suggest parasites and pathogen cans also affect competition between different amphibian species, based on their susceptibility and resulting pathology resulting from such infections.

4) The conclusion (or closing paragraph) doesn't feel like it has enough punch at the moment, but I'm sure that's something you can easily improve.

Overall, it's looking okay at the moment, just a few issues with structuring and pacing and to a lesser extend...how to I describe it...identity? I know it's probably a weird way to describe a MS, but at the moment, it feels like a teenager trying to find his/her own identity...sorry if that makes no sense. Once you shape that structuring and pacing up a bit, and work out what kind of journal you want to submit it to, the conclusion should also work itself out and it'll be a nice and tidy little review!

[Ziggy Stardust]

I hope that answers the question. Amphibians display anti-predator mechanisms that reflect a tradeoff between being able to leave a pond before it dries up and they die, and being able to respond effectively to predation risk.

Oh, ha, when I first read it I accidentally skipped over a couple of sentences. I understand now.

[Alyrium Denryle]

Just a few comments/questions:

1) What type of journal are you submitting this to, is it a herp-type journal (e.g: Herpetological Review, Herpetological Journal, etc), an ecological journal (Oecologia, Evolutionary Ecology, etc) or a conservation biology journal (Animal Conservation, Conservation Biology, etc) as it would affect what emphasis you how you pitch this paper. It won't change the overall content but it will affect how you write your intro.

2) I liked your synthesis of anti-predator response/mechanism, but the way it appeared in your MS seems slightly abrupt. Maybe there's a way you can ease it in to place it better into the wider context of everything you were discussing before that.

3) On the subject of anti-predator response/mechanism, maybe you should also touch up the effect of infectious diseases. I noticed you cited one of the Rohr paper, but currently there's a lot of work done on infectious diseases of amphibians especially in the high competitive field of amphibian chytridiomycosis. There as been some work done on the effect of trematode infection on amphibian ecology, but currently trematode research isn't as sexy as chytrid research, so most of what you find on that will be related to chytrid. Like anti-predation response, there are evidence to suggest parasites and pathogen cans also affect competition between different amphibian species, based on their susceptibility and resulting pathology resulting from such infections.

4) The conclusion (or closing paragraph) doesn't feel like it has enough punch at the moment, but I'm sure that's something you can easily improve.

Overall, it's looking okay at the moment, just a few issues with structuring and pacing and to a lesser extend...how to I describe it...identity? I know it's probably a weird way to describe a MS, but at the moment, it feels like a teenager trying to find his/her own identity...sorry if that makes no sense. Once you shape that structuring and pacing up a bit, and work out what kind of journal you want to submit it to, the conclusion should also work itself out and it'll be a nice and tidy little review!

1) This was originally a term paper for a graduate class on Wetlands Ecology. I do archive these (my term papers on various ecological and herpetological topics), and eventually plan to expand them, clean them up and submit them for publication (probably during my inter-season down time next year. This one would be bound for a conservation journal (Animal Conservation probably). Others I have written are reviews of risk assessment in anurans (J Herp or Herp Review) and another on reproductive energy allocation in garter snakes (Oikos).

2) That would be the cleaning. Sub-headings will probably also be used in order to smooth those transitions.

3) Yeah. I short changed the disease and the impacts of agrochemicals. When I expand this I will definitely go into that a lot more.

4) As I said. Term paper. Not something I would try to submit in its current form, but it is good enough for what I need it for. I do however like to post them here because most people do not get a good overview of anything related to the ecology and conservation of anurans.

[The Episiarch]

I guess with hindsight now, I can understand why you did a good job on the anti-predator response bit, I found your profile at Uni of Texas Arlington and saw your thesis topic.

Actually, pardon if this seems like a thread hijack, but staying on the herptile theme (kind of), I remember you posted something in a thread about that "climate change e-mail leak" you mentioned something about Rick Shine and some misgiving you have about him. I've never met the man, and I've tried asking around from people who have, but the opinions have been too mixed and inconsistent to form a coherent picture of his character. I'll come clean on why I'm so interested:

1) As you know, Shine is undeniably a Goliath in his field judging by his publication list (which whether we like it all not, continues to be the final measure of any scientist). I have a few good friends who are in the herptile field that are currently at various stages of grad school and beyond, I'd like them to be well-informed as to what they are up against/getting into if they are to have interactions with Shine in anyway.

2) Herptiles are becoming increasingly popular as models for studying disease ecology and host-parasite interactions, which is my field. Ever since Shine has become the designated "Cane Toad Man", he's had money thrown at him, and I've noticed he's published a few things related to cane toad parasites. I would also like to know what *I* might be up against with Shine as he's going to be an enduring feature on my horizon both in terms of geographical region and research field.

So how did you find out about some of these allegedly less savoury aspects of his personality/research-style?

[Alyrium Denryle]

I guess with hindsight now, I can understand why you did a good job on the anti-predator response bit, I found your profile at Uni of Texas Arlington and saw your thesis topic.

Woah. When did I have a profile? My wiki page here has the old version (it has changed a bit, I switched over to PhD and redesigned my experiments in light of new questions). My Academia account also has the old version. Hell, I will PM you the Rundown I sent Formanowicz to bring him up to speed on all the revisions.

1) As you know, Shine is undeniably a Goliath in his field judging by his publication list (which whether we like it all not, continues to be the final measure of any scientist). I have a few good friends who are in the herptile field that are currently at various stages of grad school and beyond, I'd like them to be well-informed as to what they are up against/getting into if they are to have interactions with Shine in anyway.

Well, apparently he is a very very nice person. However from what I have gathered he has a bit of a reputation for scooping people on their research and strong-arming collaborations. I dont know how accurate it is because I have not met him, but it was sufficient in that thread to make the point. And with 600 publications he has to be doing something shady or otherwise be very very good at securing people's cooperation. The best ecologists I know (Relyea, Werner, Cannatella et al) cannot put out more than ten a year and that is with collaborations and armies of grad students, undergrads, and post docs.

2) Herptiles are becoming increasingly popular as models for studying disease ecology and host-parasite interactions, which is my field. Ever since Shine has become the designated "Cane Toad Man", he's had money thrown at him, and I've noticed he's published a few things related to cane toad parasites. I would also like to know what *I* might be up against with Shine as he's going to be an enduring feature on my horizon both in terms of geographical region and research field.

He is a superior technician. He is probably one of the best biometricians alive. If you can get collaborations with him, your career will soar. Go into competition with him, and he will bury you.

So how did you find out about some of these allegedly less savoury aspects of his personality/research-style?

Other grad students and post docs who work primarily in systematics and ecophysiology

[The Episiarch]

Oops, I just realised after I posted that message I wasn't looking at your profile at Arlington - it was your profile on uta.academia.edu

Well I can think of a handful of good and efficient researchers who have really productive lab groups that can produce far >10 papers a year through a combination of personal efficiency, really motivated grad students and postdocs, as well as a strong network of collaborators. And I can vouche that they managed to do so without any shady stuff (though at the same time I am equally aware of research lab PIs who *are* shady) because I've seen them at work, and can easily extrapolated that >10 papers a year is well within their reach.

But thanks for your info, I'll definitively keep it in mind for future reference.

[Alyrium Denryle]

Oops, I just realised after I posted that message I wasn't looking at your profile at Arlington - it was your profile on uta.academia.edu

Well I can think of a handful of good and efficient researchers who have really productive lab groups that can produce far >10 papers a year through a combination of personal efficiency, really motivated grad students and postdocs, as well as a strong network of collaborators. And I can vouche that they managed to do so without any shady stuff (though at the same time I am equally aware of research lab PIs who *are* shady) because I've seen them at work, and can easily extrapolated that >10 papers a year is well within their reach.

But thanks for your info, I'll definitively keep it in mind for future reference.

It depends on what you are doing though. I can definitely see it with Museum work, some types of physiology or molecular work. But 600 publications? Yeeeeesh