This article isprotected rights by All copyright. reserved. 10.10 doi: lead todifferences version between this andthe ofPleasecite Version Record. th been throughtypeset thecopyediting, This article undergone has for and buthas accepted been not review publication fullpeer head: Running contributions: of Type * 4 3 Leipzig,Leipzig,Germany 04103 2 China Earthof Surface theMinistry Peking Beijing, Processes University, ofEducation, 100871 1 Wang Shaopeng webs food complex in functioning and biodiversity enhances predation Intraguild Article type :Articles DR. SHAOPENG WANG (Orcid ID :0000

Email: [email protected]: DépartementBiologie, de Universite Sher de Sherbrooke, EcoNetLab,Integrative for German Centre BiodiversityHalle (iDiv) Research AcceptedInstitute ofBiodiversity,Friedrich Schiller UniversityGermany 07743Jena, Jena, ArticleInstitute ofEcology, College Urban and Science,and Environmental Laboratory Key of for

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- This article isprotected rights by All copyright. reserved. Acceptedpredation structure, (IGP), trophicdynamics network Key Words: resolving web shednewIGP models.Our role lightfunctional ofcontribute findings onthe to and presenceIGP,reconciling of based thecontraststudies from onfood recent ecosystem functioning (e.g. or total biomass primary production) biomasses) betweenefficiency instead, they be should thatthegoverned assembly a food suggest balance webs by of web energy levels. trophic Ourresul across fluxes different at levels,higher different totaland (2) biomasses trophic(3) trophic levels, larger IGPstrength increase of Articleresults increased turnalter biomass in increase and/or carnivore showthatasIGP Results thestrength level. atro within of simulate a five investigateeffectsIGPand the ecosystem of diversity onspecies functioning. first We potentially affectsand dynamics webs. thediversity web offood Here, wefood modelst use niche energy space andflowswhich down tohigher from slows trophic lower levels, same Intraguild predation i.e.feeding (IGP), betweenconsumers share interaction that twothe Abstract

structure resource species, is commonly observed in natural food webs. IGP commonlyresource vertical foodwebs. observedexpands is innatural species, are s , the biomass of its resource its , thebiomassof increase level

the debate on structure, diversity andthe debatefunctio onstructure, diversity then extended by ofmorethen simulations d subsequent . Our simulations also. Ourthatbetween show the simulations relationship biodiversityand

Biodiversity, ecosystem functioning, energyBiodiversity,intraguild food functioning, webs, ecosystem flux, should should - species food web module with different strengths of IGP webthe herbivore food modulespecies withdifferent at strengths of

(of energy(of transf maximize theefficiencymaximize of s , simulatedfood webs maintain (1)diversity higher species at s

the energy and levels. biomass fluxes ofother trophic These er)

and persistence ts challenge hypothesis theintuitive that food energy levels; transfer across trophic s

because ofpredation release; this

ning food webs. incomplex

( i.e. the i.e.

iverse foodAsthe iverse webs.

maintenance ofspecies andmaintenance is much stronger inthe - phic level chainfood and

- o This article isprotected rights by All copyright. reserved. Accepteddynamics food easier tounders webs of all species haveinteger levels chains, trophic alongtrophic thestructure making and consequently IGP(Holt & 1997). Polis increases thevertical which characterizes feedingconsumersthe same resource that interactionsbetween two share structureand functioning onthediversity food of 2018). Despiteadvances, ofnetworkcomprehensive theseofthe understanding a effect productivity 2013;Wang and etBrose & speciesdiversity (Poisot al. 2018) (Barbieret al. investigateeffect the structureonenergy(deB ofnetwork fluxes (Jansen & Tanget Kokkoris al.2014). Recently, 2003; to theoreticians also started modularityBascompte and (Stouffer and strengths correlation 2011), between interaction ofcould food websbeenhanced by weak dynamicsand stabilityfoodIn webs1982;McCann of 2012). thestability (Pimm particular, Article diversityecosystem and functioning incompl therefore, toimprove ourunderstanding governing an species need ofthe urgent mechanisms ecosystem et functioning al.2011; (Estes (Binzerextinction et al.2011), andmight their extinction have mainly Species at oncompetitive communities. higher higher trophica bearriskof levels functioningof ecosystemset and et (Loreaual.2001;Tilman stability al.2014), they focused Levineto uncoverofspecies the(Chesson coexistence 2010) a mechanisms 2000; major goal ecology. in have Althoughnumerous and developed theories experiments studies underlyingUnderstandingand themechanisms ecosystems functioning thediversity a of is Introduction One natural importantintraguild (IGP), elementfoodis webs of complex predation Network structurehas suggested been long role toplayan inregulating importantthe

increases complexity of the whole food web (Duffy et al. 2007). Without IGP, webcomplexity Without ofthefood (Duffy et whole al.2007). tand. However, IGP atHowever, alltrophic found tand. commonly is Brose et al.Brose 201 et trophic ex food webs.ex

niche breadth of a consumer species breadthaniche and consumer of

interactions (Mc interactions webs, remainscomplete. from far

7 ;

Wang&2018). There Brose is,

a strong negativeimpact on ruyn et al.2007),ruyn ecosystem Cann et al. 1998), et al. Cann nd the

This article isprotected rights by All copyright. reserved. Acceptedwebs& B (butsee Stouffer among islargelycompetitors, it but food complex similarwhether effects unclear in occur 1997; Polis IGcondition that the ex preyis superior in coexistenceIGP when between ispossible theadditional exists thetwoconsumers, under due toresourcetwo consumers (Tilman 1982). cannot coexist However, competition their that theoretical altering IGP driverweb offoodfollowing dynamics theweakening oftop buil ArticleSchneider et al.2012) transforming biomass (Holt&Finke into 1997; 2005; & energyDenno Polis inflows control between etal. trophiclevels(Mylius deBruynal. 2001; 2007).The ettop reduced thesamestructure, within trophic levelenergy keeping energy andthusslowing flows down upward can flux, top dampen flow from thetopofdown thebottomto network.Networkstructures this thatslow unexplored (Irigoien& IGPof functioning, onthe diversity and remains food webs, especially largelyin complex levels (ArimRiede natural &et in al.2010). ecosystems Marquet 2004; d compet may remarkablymay - Very studies few have d Foodcomprise websfeedingbetween andenergy through links which nutrients species, up of biomass athigher trophic asthe levels,

can trophic control trophic research e release species at lower trophic levels and speciesatlowerenhanc release trophic levels Kondoh 2008)

for the same for the

investigated how IGP twoinvestigatedcoexistence mightconsumers how influence theof re .

. The increasedThe lower biomassestrophic at levels mayin turnaffectthe -

de Roos 2011). Roos de shape

. InIGP. sense, this tomaintaining higher contributes a diversity resource &1997). (Holt Polis ascompte 2010). - iscussed the effect of IGP onspecies the effect diversity. iscussed of down controlIGP (deBruynal. 2007). et energy and biomass fluxes

ploitative competition for theresource

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In the absence of the IGPInthe the link, theabsence of distributions distributions - up effect themajor becomes - e their efficiencye their of down effect. T

in food webs by acts assuchacts a However, aken together Earlier Earlier ( - Holt & down the effectsthe

, This article isprotected rights by All copyright. reserved. IGPIGP (i)adding at links: the herbivore i.e. H by level, and thetwoherbivores carnivores. are inturnconsumed theeffect by both of investigate We H startWe a with five Methods structure, food webs.functioning incomplex diversity and results demonstrate the fundamen levels,the relation strengthens andit ecosystem between biodiversityand functioning. Our demonstrateIGP thatbiomass, andenergy increases diversity,fluxes species across trophic IGPhow affectsm functioning thediversity and of alter energy food species and complex webs biomass and flows. thensimulate examine We food weband speciesIGP investigate modulehow withfive trophic levels atdifferent links species and energyacrosstrophicleve diversity,fluxes biomass yethas exploredrigorously. be to trop maximum species trophic cascades this trophicexponentially level (Wangwith the maximum Brose & for 2018).explanation One In foodLoreau webs, however, complex primary 2010). the productivity increases relationmonotonic primary between foodand chain productivit length IGP,In in foodwebs. without chains cascade food theinanon strong trophic results 2

Accepted), and twocarnivores (C Article contrast that is In we study, this usedynamicalexaminetheeffectIGP foodwebto on models of IGPThe also presence alter the between may of and relationship functioning diversity . The weakened cascades. The trophic then

hic level primary& and productivity(Wang Brose 2018)

by mixinglengthsbetween ofvarious chains anyof andtop basal pair ,

- in complex food webs, IGP food webs,in complex can thestrength significantly weaken of links species module ofone thatconsists (H plant(P), twospecies herbivores 1

and C tal importance of IGPtal importance andcontribute of toreconcilingthe

2 ) (Figureboth herbivores, consumed plantis The by 1a). generate between a relation smooth the ultitrophic ecosystems.ultitrophic Our simulations 2

consuming H

ls. We start als. We with simple y(Oksanen et al.1981; 1 , b ; (ii) at; (ii) the carnivore ut this hypothesis this ut - 1

and This article isprotected rights by All copyright. reserved. Acceptedpreference(i.e.consumers thefractiondiet) of that belong ofon resource their species tothe consumers.graduallyIGP (ii) We of thefeeding by links decrease reducing thestrength removalIGP simultaneously of will and links foodconnectivity reduce web the IGPproportions ofall thatwere theallometricgenerated links niche by Notethat the model. gradien simulated food webs a proportion include of 20 feeding the the same interactionswithin Under trophic(Figure level 1b).thisdefinition, chain connecting fo the calculate the shortest considerable (FigureIGP links of number IGP follows:we we 1b). firstHere define as links topology values and animal allometricniche variant al.2016). model(Schneider et ofthe Articlespeciesecosystem diversity and functioning.generated Networkstructure with an is equations which ofspecies wi biomass, competitors onH than H accordingly. coexistence we Tofacilitate ofallass species, that of C IGPgraduallyIGP, increasing by thestrength i.e. thefeeding of of H preference speciesIn addition, we biomass andenergy also arerecorded. investigate fluxes th population dynamicsIGP andaddition ofand afterthe before thetemporaldynamics links, of level, i.e. 2 determin t of IGPIGPt of(i) twoways. simulatethelossof We in byrandomly removing different We then simulate complex food thensimulateWe web complex investigate modelsto IGP on effects the of

(i.e. 2

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C on C

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H consuming C 1 1

e has ahigher attackrate than species arespecies preassigned first sampled from and examinehowthe species equilibrium biomass andenergy change fluxes

1 the feeding probability between any feeding probabilityand between the thus the twospecies

and H - chain basedeach trophiclevel oftheshortest chain i.e. species, thelength for cal species and the abiotic resource;IGP speciescal abiotic andthen areas the links identified 2 , respectively. dynamicsaregoverned by Population differential 1 ; and(iii) at herbivore both simulate We and levels. carnivore ll bell described later. H . 2

The resultingfood The webs a usuallycontain

when feeding on -

46% IGP46% Again, manipulate links. a we

ume that H body size

Briefly P ) and C , aofplant number

ranges 1

is a better competitoris a 1

and C ; these body size

food

generality of 2

2 on H

e effects of are better - web 1

or (20) This article isprotected rights by All copyright. reserved. all otherNote parameters thattheparameterization their and values has inoursimulations. becomes an over species empirical thatintraguild reported studies formed predation 1 prey IGPstrength links. of feeding preference ofconsumer q controls the (eitheranimals) plants or resource species The functional dynamics which follow: of Here, species multi down controls. resource trophic speciesatlower levels (i.e.non same (shortest

determines

Accepted Article

the to be -

species predator

The dynamics ofthe i in

resource speciesresource

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P different taxa no larger than that no largerthan

i

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omnivor strength

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of predator interference(

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Polis etal. 1989 Polis F

and

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ji

ule

, describes rate of species theconsumption consumer

five

for theshared

A

ny

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j

McCann

j

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predator species species on resource species

ions. Specifically, the biomass dynamics ofaSpecifically, thebiomassdynamics ions. plant

j

(

A

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j ) are described as follows:

& Hastings 1997

module and complex food webs aregoverned bycomplex module and )

;

, where (2) inthe case that resource species resource (

type II type Skalski & Gilliam 2001; Lang & 2001; Gilliam Skalski al. 2011 et

- to to

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R a

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type IIItype

See Table 1 for explanations of explanations for TableSee 1

based on two considerations:based (1) ontwo

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This article isprotected rights by All copyright. reserved. across Notethat in simulated food webs. and primaryand speciesvertical diversity productivity) metrics (total richness and diversity) request) (=500× (removingIGP orweakening links) II intermediate: 100, food webs eachthe under of change plant community: The isdefined primaryflow pooltothe as from productivity theabiotic thetotal nutrient ratesall predator for total energy between twotrophic fluxes levels Specifically,cal we total feeding these rate)between assumed as carnivores well asand (species omnivores), that feedplantsoronbothand animals, including thus on exclusively true herbivores threespecies within biomass diversity trophic and groups: total plants,herbivores (species functioning variables). ourresponse (as explanatorynetwork investigate structure (asand variable)effect ondynamics our its and because struct bodyaffectsboth size not incorporated suggested constraints recent size theory byal. (Schneider et2016).Thisis

Acceptedand Article

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×2×2×9)

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once below their 10 biomass fell

high: 500; see 500; 1)high: Table

. We investigateWe species diversity, how energy biomass and fluxes four

All simulations areAll simulations performed inMatlab

between these two trophiclevels these two between . In. three levels supply ofnutrient rates( our results and nine IGPgradients, of we and simulatea nine total ure ourobjective and but dynamics, manipulate here isto simulations trophic groups trophic

our simulations, alltheseour simulations, variables are determined .

With two ways of simulating IGP twoways ofsimulating loss With l and and that that and and

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This article isprotected rights by All copyright. reserved. Acceptedconcentration, between H increase and todecrease accordingly thatof 2a). herbivores (Fig. Over flow cause from herbivores tocarnivores 2b), (Fig. which start herbivores onplants increase decreasebiomass to 2).Following (Fig. thetotalfeeding theincreaseinplant biomass, of rate decreased release feeding rate from toH P flux predator) and energybeforefluxes and IGP afteraddinglink the afiveIGP in ArticleResults wereremoved generatedIGPmodel) and fromfood weakestwebs the niche (i.e.99% with original links relationships andcompare thembetween strongest foodwith webs webs (i.e.original food (Wang could alter between the relationship ecosystem biodiversityand functioning infoodwebs differentfrom the Brose(2018), weca was trophic web’s measured by thefood ofWang& maximum level; tomatch the prediction by lower s

to increaseThe(Fig. biomass increase 2a). inherbivore

& Brose& ofdeterminants wecalculate the coefficients ( 2018), We firstIGPWe investigateeffectchange monitoring by the species ofthebiomasses of

- . ImmediatelyIGP afterthe. link level processes (e.g. processesnetwork supply, level vertical The structure,nutrient etc.). diversity 1

and H - species module species

or alter 2 ) with lowest preference 2 afore is

s increase lculate thethe prey trophic level using lculate

the biomass distribution acrossbiomass distribution trophic levelsthe middle (i.e.from greatly decreased due tothe reducedofH feeding preference mentioned shortest mentioned s

s the biomass of the plant andthe biomassofcarnivores, theplant

s

(Fig. 2b), and the biomass ofherbivores 2b),biomass (Fig. and stop the

P andP cause ,

i.e. 1%, i.e. 1%, is - chain definition. To test the hypothesis that IGP Totestthehypothesis definition. chain that s added, thefeedingadded, of rate H

its biomass toincrease biomass its and total herbivore on intraguild between H

s -

averaged which approach, is the results in

total preys 1

(as prey) (as prey) biomass ofcarnivoresbiomass to ) IGP.) r decreases thenutrient all, addingIGP the link 2

) of these) of an increasean inenergy 2

on P (i.e. P the energyon

s

and H declining and 2 2

on P; this this on P; -

(as heavy to This article isprotected rights by All copyright. reserved. plants, herbivorescarnivores) and IGP increase links IGPall increase with su IGPrelative strength links of results betweenwaysIGP, i.e.changing thetwoofmanipulating either number the orthe IGPenhanced in food webs complex IGP in levels alsoincrease ( plant, herbivoresca and IGP links consequence energy ofdecreased tocarnivores from (Fig.Finally, fluxes herbivores as 3b). S4 cause increasedtheir this biomass; herbivore turnsuppressebiomass in increase (Fig. 3 and way.IGP Asthe strength betweenH link of the S1: top pply rates

Accepted ArticleIGP). The atthecarnivorelevel alsoresult - Figs. heavy),and carnivoresenergy between andfluxes increase, both the trophic levels different all s

its biomass and biomass primaryits (Fig productivity todecrease The total species richness, total biomass andThe totalbiomass total species richness, investigateWe Similarly,IGPcarnivore at thelevel the release resultsSimilar S2, S3 S2, are (Fig added orenhancedadded at herbivore both and carnivore thebiomasses of levels, the , Appendix S1: Fig Appendix , ). increases increases s complex food webs. O complex .

s

4 , the species richness and total biomass ofall three groups, thespeciesrichness and total (i.e. trophic , Figs. Figs.

Appendix S1: Figs. S1: Appendix (Figs. 4,

are species species rnivores allincrease,rnivores energybetween different andfluxes the trophic the found if the IGP strengthlink found ofthe 3c

, ,

total Appendix S1: Figs. S1: Appendix and under Appendix S1: Figs. S1: Appendix diversity and ecosystemdiversity functioninggradientof along a

generally . energy

S4 ). Note that the herbivore). Noteconstant. that biomass remains verall, o

different types functionaldifferent of responses S5 &S5 S6 fluxes betweenfluxes trophiclevels(Fig increase, exceptincrease, species for theplant richness s

in areduced of total biomass carnivores asa 1 ur simulations show simulations ur

and H S1 S1 ). S5 &S5 S6)

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S4

increase the herbivore species and in herbivoreand species the

). .

s A . 3b is s the number ors thenumber strength of s s increased inacontinuous , , the biomasses ofthe plant , thebiomasses

Appendix S1: Figs.Appendix the plant speciesandthe plantP generally

s of the food webof the . 2 consistent

, and nutrient Appendix Appendix crease S1

&

This article isprotected rights by All copyright. reserved. AcceptedIGPthat at onetrophic ofresource couldincrease and level its this level, thebiomass classicanalysis this confirmed resultand withamulti extended biomass ofthesharedresourcea trophic throughcascade effect & 1997).Our Polis (Holt functioning. food webs,complex as between aswell enhancingandrelation ecosystem the biodiversity IGPthat increase importanceIGPfor of biodiver wea have Our poor ofitsimplications. study understanding demonstrate IGP natural in ubiquitous Marquet ecosystems& is (Arim Riede 2010);however, 2004; et al. Discussion (Fig 0.0 ArticleIGP links 0.4 community biomassproductivity orprimary exhibit decreaseat carnivore level stay roughly constant also increase. energyfrom However, the the fluxes those herbivores tocarnivoreswithin and herbivores) bothincr productivities energy fromnutrienttoplants) and theabiotic from secondary plantsto flux (i.e. energy flux carnivores which remain 9 8 s ~0. ~0.5 .

5 Early studiesonthe three Across simulated foodecosystem webs, calculated functioning bytotal aseither 17 ,

7 Appendix S1: Fig. S1: Appendix . ; ; slope= But their correlations areButcorrelations significantly theirreduced exhibit slope = 0.031~0.052 lower supp nutrient

s

constant. s

slightly trendsdecreasing the species diversity, biomass, andtrophic levels energyacrossthe speciesdiversity,fluxes biomass, in 0.098~0.11

But atvery supply, lownutrient S7 ). ) with verticalfood webs diversitywith in sityfunctioningOur food andwebs.complex modelsshow of ly )

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or weaker (Figs. species IGP module showed that IGPIGPspecies the that increase showed can module ease, and the total energyease,and the herbivore thetotal within fluxes level at intermediate or 4, Appendix Figs.S1: Appendix (

with increaswith r 2

= 0.3 s 3

a strong ( correlation positive ~0. high nutrienthigh supplyand slightly 38; slope= 0.075~0.088 ed the richness and biomass of the richness andbiomass

in food webs with webs with in food

IGP S5 &S5 S6) -

species IGP module. ItIGPspecies module. (Fig. 4d,e .

s

many

). ). the fundamentalthe The primary (i.e. much

and ) IGP links less r

strong 2

= ( shows r 2

=

This article isprotected rights by All copyright. reserved. Acceptedpresenceour results ina IGPcould showthatthe of result and effectand functioning isbeyond between biodiversity thisstudy. scope That the of said, and biomass offood (Schneider webs al. Wang& 2016; et Brose 2018). Distinguishing cause feedbackbecausecreated may bea higher diversity the also enhances potentially (McCann et et al.2002 al.1998;Neutel down pressure and to more 2007; Brose 2008) niches forcompared coexistence discrete species space niche (Duffy tothe simplified, et al. betweendecreases and competition (Holtcreates consumers & 1997) exploitative new Polis 2010). One cou explanation food webswith the number increases ofthree levels. resultwithrecent isconsistent that This the persistence species incomplex findings of Article build control atand which (DeBruynet enhance releaseslower al2007), trophic the species levels IGP imped those between links levels, IGP.down control with By interactions strengthening trophic feeding within levels relative across trophic (Fig levels enhanced the capaci food ofcomplex simulations IGP web that models,whichthewhole showed across food web primary whole productivityresults the ecosystem. These were extended further by our of higherlevels trophicand (Fig lower increased turnhave biomass thebiomassand in ateven energy cascadingfluxes effectson , ontheother hand, - up of their biomasses. Our simulations also show that IGP alsoOur that show simulations cou preyresource or s . Both patterns . Furthermore ty of ecosystems abiotic exploiting resources of ty in biomasses and building

slows species .

4). All these could observations beexplained bythe reduced top ld bethe expandedIGP, vertical which niche space with

down were , , the presence of IGP the presence of which, hand, ontheone

. energy betweenfluxes trophiclevels demonstrated

2). InIGP particular, 2). attheherbivore increases level the e

; the vertical flowofweaken energy and thetop Rip &Rip McCann 2011 - species IGP (Stouffer&Bascompte modules species ld increase speciesacross trophicld increase diversity

to promote splits splits

creates much stronger correlation between the feeding of predators activities

community ). In a positive case, this many

weak interactions and weakensand persistence productivity - top down

- -

to This article isprotected rights by All copyright. reserved. Accepteddemonstrating effectanothercommonly thepositive of observed structure innatural Fontaine species in shown that non May’s inrandomly prediction derived ecosystems, was studieshave many structured later in contrast thediversity high with complexity observed and innatural rigorous test. hypothes and essential forandIGP thepresence biomassof production, may cause a decrease of and maintenanceIGPconditions, is more important, andthus toincreasing contributes food w ArticleMcCann heuristically usto 2012). Thisleads atheassembly propose balance hypothesis: of down control cascades andpersistence trophic impair the can of be detrimental for th Inhave lower andwords, diversity, total biomass. efficiency productivity other a couldhigher energy i.e.by transferIGP increased, weakening removingfood nevertheless or webs links, (GarlaschelliBellingeriBodini et al. 2003; and governed thatpromotethe by constraints efficiencyenergyof trophic levels deliveryacross webs, comparedfood simple tothatc in cascades inastronger and result relationbetweendiversity andfood productivityin complex them. ThisconfirmsIGP could the recent weaken that hypothesis oftrophic thestrength biomass at higher trophic levels.biomass athigher trophic biomass levels. across trophic ebsof anoutcome trade is In May thatcomplexity(1973) concluded seminal his monograph, stability, impaired Our findingschallenge hypothesis the intuitive assembly the that foodmaywebs be of

es ( 2010; Tang et al. 2014; Jacquet etal. by 2014; et 2016).Ouradd discussion tothis al. 2010; Tang results ecological communities (Jansen ecological& communities F

ig - . random structures of food webs can enhancerandom webs the offood structures can

4, Appendix Figs.S1: Appendix e complexity offood and webs, functioning strong simply top because - offs between efficiencyIn nutrient between offs and persistence. In nutrient Our resultswiththese seem simulation be to consistent S hainsBrose (Wang& 2018). 5

and

- Kokkoris 2003;Broseet al.2006;ThébaultKokkoris & limited conditions,energy limited efficiency is transfer

S 2016). In as our theefficiency2016). simulations, of 6 ), but further are investigations

species persistence persistence

ecosystems. While While ecosystems. (Rosensweig 1971; and diversity of needed for aneeded for diversity diversity - rich - This article isprotected rights by All copyright. reserved. Accepted contributed tointerpreting themanuscript. and revising theresults WangS. Research(iDiv) Halle gratefully Centre acknowledge supportofIntegrative theGerman for the Biodiversity and This work wasby supported the Acknowledgements by pro incorporating evolutionary development ofecosystems. stage(Irigoien Schneider& 2011; Roos the long may de et be al.2012), selectedin etUlanowicz al.2007),trai 2000;Neutelspecies thus increase ofenergy and theirtheexploitation complexity & (Schneider 1994;Nielsen Kay & ArticleFrom ofview, point a the thermodynamical successional tends to development ofsystems betweenenergy hypothesis webs, abalance for theassemblyfood which understanding emphasizes of diversityfunctioning food in webs. and Our findings inspir maintenance biodiversity and steprecon functioning, of towards isanew offoodIGPimplications structure. web revealsof the Our in that study role thepositive 2016). Thiscalls2008; Jordano urgentlyforthe functionaladvanced anof understanding e.g.extinction, invasion,andextinction byofecological species (Tylianakis et interactions web diversity. namelywhichcommunities, alIGP,

the

Natural tostructural are susceptible foodwebs changes inthefaceglobal changes, of National Key Research and Development ProgramNationaland Research ofChina Development (2017YFC0503906). Key UB designed and theresearch, wrotefirst thestudy, performed draft. the

- transfer efficiency and persistence,transfer species rather

- Jena - Leipzig German by(FZT the funded Foundation Research 118). Understanding the National Natural Science Foundation of China (31870505) NaturalScienceFoundationNational of China cesses should be a promisingfuture shouldbe cesses for direction research. so increasedand persistence species origination and functional importance of IGPorigination andfunctional importance of ts that affect IGP,ts thataffect body e.g. and size life

e

us to us to

develop develop than any singleany aspect. than

yielded higher food ciling thestructure, a balancea All authors - term term

al.

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This article isprotected rights by All copyright. reserved. Accepted C., &DeBruyn,energetic Strong, K.S.,Moore, A.M.,McCann, An J. D.R.(2007). (2000).Chesson, ofmaintenance P. Mechanisms of species diversity. R. Brose,U., Williams, J.,& Allometric scaling(2006). Martinez, N.D. enhances stability in Brose,U., Blanchard, J. L., Hartvig,A., Galiana,Hirt,M., M.,R N., Eklöf, amongBrose, foodexclusion U. (2008).webscompetitive prevent Complex producer ArticleBinzer,Brose, O.,& B. A., Eklöf,A.,C.,Riede, J. U., Curtsdotter, Rall, Bellingeri,& M., Barbier, F.,Loreau,& Bunin, M., Arnoldi,M.(2018). J. Generic G.,patterns assembly in Arim, M.,&Intraguild A.(2004). Marquet, P. awidespread predation: interactionrelatedto Reference 2507 species. Applied Ecology (2011). The modelcommunities. susceptibility in of toextinctions species ecosystems. 201710352. ecologicalcomplex communities. species biology. structure ofecological systems Inframework for control. trophic Ec food webs.complex approaches. Predictingconsequencessize the ofspecieslossusing ology andSystematics - 2514

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This article isprotected rights by All copyright. reserved. c q e e k r D T meters Para 1. Table i 2 1 i

Accepted Article

-

plant species plant species Mass species ofplant growth rate Half species ofplant growth rate Mass isrefreshed thenutrient which by rate turnover Nutrient concentration supply Nutrient on resource species species resource on species oftime) ofconsumer the fraction (i.e. preference The interference the Aparameter ( II type response: functional A species handlingofconsumer time The species ofconsumer attackrate The animals consuming when efficiency Assimilation plants consuming when efficiency Assimilation species animal Mass Parameters q Explanation =1) and type III ( type and III =1) parameter that determines determines that parameter

strength ofpredator strength - saturation density for the the for density saturation - - - specific metabolic rate of rate metabolic specific of rate metabolic specific maximum specific

j j

on resource species species resource on species resource on

that determines determines that i

and their valuesand used inthe simulation.

j

q

i =2)

i i

i i j

figures in specified otherwise except 0 2 10 0.85 0.45 0.02 0.02 5 0.15 0.25 100

module five in the Values

-

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2

&

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3

, ,

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species species

, ,

animal. is plantor the when resource U 0.85 0.45 U U U U 0.25 20, 5, figures in specified otherwise except 0 2 1, U .05

webs food in complex Values [0.05, 0.1] or 0.1] [0.05, 0 [0.01, 0 [0.01, 5] [1, 0.15] [0.05, [0.5, 1.5]×10 [0.5,

100

4

. . , 500 , 03] 03]

-

3 U

[0.01, 0.02], [0.01, , This article isprotected rights by All copyright. reserved. S4 IGPs,modules depict the the strengthmanipulatedx along ofwhich was the dynamics the five of InIGPand (c,f)and simulated the carnivore atbothherbivore we thesimulation, levels. increasedIGP:IGP strength(a,d)carnivoreIGP of at level, level, the attheherbivore (b,e) Figure 3. S1: Appendix dashed vertical line). See web reached it dynamicsuntil equilia werenew simulated H the grey vertical dashed line). Thenfeeding addherbivores we a between link thetwo H dynamics the five of IGPan attheherbivore link level,H i.e. between Figure 2. different levels. trophic and secondary (yellow). each carnivores within TrophicIGPsat represent dashed links box different differentcolor levels in trophic species by and prey plants,adjusted their ofspeciespositions aremainly determinedby theshortest chain length between thefocal Figure 1.

2 , such thatH

Accepted Article for ona same exhibited logarithmic data scale. in(d,e,f)

in (a,d),

The dynamics of species dynamics energyThe and biomass (a) (b) and fluxes before afteradding The equilibrium species biomass (a equilibrium The IGP a in five Fig. for S2 same ona data exhibited logarithmic as scale. in(b) 2

has thesame feeding H1and ( P preference on

- -

species module species IGP reaches it modulespecies without until equilibrium in (b,e), -

species module (a) and a moduleandspecies (a) Appendix S1: S1: Appendix

and

under different feeding preference on the IGPunder differentfeeding the (e.g. link preference on Fig. for S1 resultsIGP scenarios under other of and s: plants (green), herbivores (red), carnivoress: plants(green),(red), (blue), herbivores

- averaged trophiclevels. depict boxes averaged Dashed

-

c) andc) in (c,f) 1 complex food web (b). verticalcomplex The

and H

). Greyarrows five inthe energy (d fluxes 2 . In. we first ran thesimulation, the

brium (on theright ofthe grey

-

f) with graduallyf) with

- axis. See Figure

(on the left of - species species

). Food 1

and This article isprotected rights by All copyright. reserved. parameters determinants ( areaxes scale.Lines ona logarithmic rep y verticaltrophic level. maximum by diversityisrepresented food Notethat web’s the the intraguild thatontheshared preysof methods).The (seeoursimulation resources to1% IGP andlinks, those withweak were links by obtained r 100 and IGPwebs many with weregenerated links (parameters: by originally foodmodel web the with vertical diversityinfoodwebsfew(b,e) many with (a,d), Figure 5. Figs IIIsimulated foodType webs. functional follows The ( response IGP.strength line represents Each of for themedianacross value metrics respective 500 that onnon preference.In case,feeding IGP thesecond most the preferenceat on is resources In(dashedIGP case, ornon thefirst lines). (either all links preferenceIGP on compared resources tonon gradually(solid lines), and (ii) IGP of reducing thestrength by relativefeedi the decreasing IGPproportion of fromfood links theweb complex modelgenerated niche by model the ( food websintermediateacross under complex trophic( in levels Figure 4. T

Accepted Article= 5;d,e, .

S5

q and

=2), those with fewIGP=2), by removing those wereoriginal withobtained IGP links 99% of Effects of IGPon species biomass (b,e)energy ofdiversityand (a,d), Effects (c,f) fluxes Relationships ofprimaryRelationships productivitycommunity (a,b,c) and biomass (d,e,f) total f) nutrient supply. We manipulated IGP in two ways:f)IGP intwo manipulated nutrientsupply.We randomly aremoving (i) - T IGP (see The resources x maintext).

S6 for results under( other results parameters for S6 = 100and r 2 ) and( slopes q

= 1. b

) were shown.See resent least - IGP resourceseach speciesconsumer for - axis representsaxis orrelative theproportion Appendix S1: S1: Appendix T -

squarefits, andthe coefficient of = 20,500and educing preference thefeeding on

- IGP) feeding have same andIGPs. weak (c,f) Food T Fig q =2). See=2). = and 100;a,b,c) low very . q

S7 forS7 results under

= 1).

Appendix S1: S1: Appendix

as high as - T ng

= This article isprotected rights by All copyright. reserved. Accepted Article

This article isprotected rights by All copyright. reserved. Accepted Article

This article isprotected rights by All copyright. reserved. Accepted Article

This article isprotected rights by All copyright. reserved. Accepted Article

This article isprotected rights by All copyright. reserved. Accepted Article