814 Index speciation (continued) research benefits 6:636–637 species differences 6:636–637 within-species versus between-species variation 6:637 geographical modes characteristics 6:633–634 classical allopatric speciation 6:634 founder effect speciation 6:634–635 hybridization 6:635 parapatric speciation 6:635 peripatric speciation 6:634–635 sympatric speciation 6:635–636 keystone species biomonitoring processes 3:125 ecological perspectives 3:5 multispecies interactions 6:722, 6:723T myriapods 5:428 neutral theory 5:511 reproductive barriers 6:620–621, 6:622T research summary 6:627–628 speciation–extinction rate relationship 3:415, 5:439–440, 5:440F speciation modes allopatric speciation basic concepts 6:621–624, 6:621F dichopatric speciation 6:621F, 6:622–624, 6:622T, 6:623F general characteristics 6:621–624, 6:622T peripatric speciation 6:621F, 6:622T, 6:624 salamanders 6:622–624, 6:623F general characteristics 6:621–624 neutral theory 5:515 nonallopatric speciation allopolyploid/amphiploid speciation 6:627, 6:627F autopolyploid speciation 6:626 basic concepts 6:621F, 6:624–625 cichlids 6:625 direct allogenous speciation 6:627 general characteristics 6:621–624, 6:622T interspecific hybridization 6:626 introgressive hybrid speciation 6:626 Mimulus cupriphilis 6:625 parapatric speciation 6:621F, 6:622T, 6:625 recombinational hybrid speciation 6:626 reticulate allogenous speciation 6:627–628 Rhagoletis fruit flies 6:625–626 spontaneous thelytokous speciation 6:626 sympatric speciation 6:621F, 6:622T, 6:625 subspecies taxonomy 7:45–48 historical background binominal versus trinominal nomenclature 7:45–46 divergence theories 7:46 levels of variation 7:45 theoretical challenges 6:620 underlying assumptions 6:629 species abundance distributions (SADs) 5:510–511, 5:513–514, 5:513F, 6:655, 6:656F species–area relationships (SARs) 6:640–650 biodiversity conservation background information 6:646–648 incidence functions 6:649–650 loss management strategies 6:648–649 nestedness measures 6:649–650 relaxation concept 6:647 species loss 6:643F, 6:646–648, 6:647F summary discussion 6:650 biodiversity dynamics modeling 5:321–328 background information 5:321–322 countryside habitats 5:323–324, 5:323F native habitats 5:322–323, 5:322F biogeographic research 1:583–585 birds 6:659–660, 6:660F, 6:662F diversity patterns 6:710 functional form curve shapes 6:643–644, 6:643F extreme value model 6:644–645 power-function model 6:644 random placement model 6:644–645 self-similarity model 6:644 neutral theory 5:510–511, 5:514 parameter interpretation alternative interpretations 6:646 canonical slope values 6:645 island–mainland differences model 6:645–646 isolation effects 6:646 slope parameter 6:645 summary discussion 6:646 plant biodiversity–climate relationship 2:115, 3:116, 3:117 research background 6:640 sampling practice basic concepts 6:641–642 independent sample area 6:642, 6:642F nested sample area 6:642, 6:642F species assemblages 6:659–660, 6:660F, 6:662F statistical practice 6:642–643 underlying mechanisms area per se hypothesis 6:640–641 edge effects 6:641 habitat diversity hypothesis 6:640 multiple causes 6:641 passive sampling hypothesis 6:641 research background 6:640 resource concentration hypothesis 6:641 species richness 6:640, 6:640F species assemblages 6:651–666 assemblage properties general discussion 6:663–664 historical variability range 6:665 indicator species 6:663–664, 6:664F knowledge gaps 6:664–665 definition 6:651 descriptive processes abundance lists 6:652T, 6:653T beta diversity basic concepts 6:659–660 biogeographic scales 6:660F, 6:661, 6:662F characterizations 6:659–660, 6:660F habitat and dispersal limitation scales 6:660F, 6:661 sampling scale 6:660–661, 6:660F temporal beta diversity 6:662, 6:662F characteristics 6:652 correlation/covariation measures abundance versus mass 6:657F, 6:658 abundance versus occupancy/range size 6:657F, 6:658 abundance versus traits 6:658 energy versus mass 6:656–658, 6:657F general discussion 6:655–658 traits versus traits 6:658–659 mean and univariate descriptions 6:652–653, 6:652T, 6:653T spatiotemporal variations climatic forcing scale 6:663 evolutionary scale 6:663 indicator species 6:664F population dynamics scale 6:663 sampling and detection errors 6:662–663 species–time relationships 6:661–662, 6:662F temporal beta diversity 6:662, 6:662F variation measures basic principles 6:653 body mass distribution 6:654–655, 6:654F lognormal distributions 6:653–654, 6:654F, 6:656F, 6:657F range size and occupancy distribution 6:655, 6:656F, 6:657F species abundance distributions (SADs) 6:655, 6:656F species- versus individual-level distributions 6:652T, 6:653, 6:653T, 6:654F traits and trait distribution 6:655, 6:656F extinction risks 7:192–194, 7:193 process drivers 6:651 research summary 6:665 spatial scale 6:651–652 Species at Risk Act 2:225–226, 7:197–199 species coexistence 6:667–678 background information 6:667 coexistence mechanisms basic concepts 6:671 landscape heterogeneity exclusion mechanisms 6:676 spillover effects 6:676 local coexistence models food web effects 6:674 local habitat heterogeneity 6:674–675 mechanistic models 6:673–674, 6:673F nonlinear consumption 6:675