APPENDIX: PATIERNS OF SPECIALIZATION Statistical rationale progress, a second variant of cluster analysis may be considered more appropriate here. In optimal (non-hierarchical) clustering, A variety of ways is available for exploring axes or groupings the analysis sorts the species into a variable number of internally­ within multivariate data sets. Principal components analysis, for homogeneous clusters. Group properties of the cluster then example, would identify any axes of specialization to which the become equally important as properties of their individual different attributes might variously contribute, both in kind and in members, and the analysis will not necessarily produce the same degree. However, the most suitable indication arises from the outcome as would an hierarchical analysis into the same number assumption that the values of certain attributes for a particular of clusters. group of species have evolved through simultaneous selection-a This is the approach which we, and Grime eta/. (1987), have composite response on the part of several attributes to a set of followed. They are both successive instances of a 'rolling external environmental pressures. Further, these sets of attributes synthesis', a research strategy which periodically draws together may well have evolved in such a way that coherent groupings of the current state of quantitative knowledge of native plant species species which possess them can now be identified, each with into a statistical and comparative overview. characteristic values, or ranges of values, for each of the attributes. This being so, a cluster analysis is indicated. Two variants of cluster analysis exist. The first employs a The current database hierarchical method in which each species belongs initially to its own separate class. The two classes with the highest similarity are The data used in this attempt to identify strategies of ecological then merged into a cluster, or group, and all other classes are specialization have been drawn mainly from the summary tables redefined according to an agreed criterion. This process is then of plant attributes given in Chapter 6. These permit a multivariate repeated until all species belong to a single cluster, intermediate synthesis to be made of the more important available data, paying stages in this process providing the information sought. Since it is particular (but not exclusive) attention to those attributes which plainly less likely that co-evolution of plant attributes will have have a direct bearing on predictions made by recent Plant Strategy occurred in response to fine interrelations between closely similar Theory, as in Table 3.3. The attributes selected are summarized in species than it is that it has followed broader axes of evolutionary Figure A.l. Figure A.l An explanation of the 27 plant attributes of the established and regenerative phases which were used in the cluster analysis. For each attribute an abbreviated title is given in captialletters, followed by a fuller title; the categories recognized within the attribute are listed next, with an explanation of the corresponding system of scoring used in the analysis (normally an integer scale running from 1 to 5); the number of instances of each category then appears, with a bar chart in which a single asterisk represents the presence of two species; finally, the number of species for which the attribute could not be supplied is noted. Attribute: DNA (Amount of DNA per nucleus) <2. 0 56 **************************** 2.0-3.9 57 ***************************** 4.0-9.9 51 ************************** 10.0-19.9 4 30 *************** 20.0+ pg 5 15 ******** Missing values: 64 Attribute: SPREAD (Lateral spread of the individual plant) Therophytes 78 *************************************** Perennials <100 mm 85 ******************************************* Perennials 110-250 mm 36 ****************** Perennials 260-1000 mm 4 24 ************ Perennials >1 m 5 50 ************************* Missing values: 0 654 APPENDIX: PAITERNS OF SPECIALIZATION Attribute: FTIME (Time of flowering) Jan., Feb. or March 1 23 ************ April 2 38 ******************* May 3 63 ******************************** June 4 89 ********************************************* July onwards 5 60 ****************************** Missing values: Attribute: FOUR (Duration of flowering) Up to 1 month 1 11 ****** Up to 2 months 2 77 *************************************** Up to 3 months 3 89 ********************************************* Up to 4 months 4 48 ************************ >4 months 5 48 **************~********* Missing values: 0 Attribute: LIFEFORM (Raunkiaer life form) Therophyte 1 54 *************************** Geophyte 2 16 ******** Hemicryptophyte 3 169 **************************************************************~~··· Chamaephyte 4 18 ********* Phanerophyte 5 16 ******** Missing values: 0 Attribute: RGR (Mean potential relative growth rate) (0. 5 1 4 0.5-0.9 2 33 ***************** 1.0-1.4 3 58 ***************************** 1.5-1.9 4 15 ******** 2.0+ per week 5 11 ****** Missing values: 152 Attribute: LIFEHIST (Life history type) Ephemeral 1 48 ************************ 2 0 Short-lived perennial 3 54 *************************** 4 0 Long-lived perennial 5 171 **************************************************************~··· Missing values: 0 Attribute: LPHENOL (Phenology of the leaf canopy) Seasonal 1 92 ********************************************** 2 0 Intermediate 3 154 **************************************************************~*** 4 0 Evergreen 24 ************ Missing values: Attribute: STOR (Storage organs) In seeds only 1 48 ************************ 2 0 Throughout the plant 3 115 ********************************************************** 4 0 In specialized organs 5 109 ******************************************************* Missing values: Attribute: LTEXT (Leaf texture) Succulent 1 66 ********************************* 2 0 Mesomorphic, not succ. 3 130 ***************************************************************** 4 0 Hard, wiry or tough 5 75 * * **** ******* * * * * * ***** * ** * * *** * * * **** Missing values: Attribute: PLOIDY (Ploidy) Diploid 1 137 ********************************************************************* 2 0 Intrageneric polyploid 3 87 ** * **** *** ** * ** *** * * * * * * * * * * * ************ * * * 4 0 Intraspecific polypi. 5 36 ****************** Missing values: 13 THE CURRENT DATABASE 655 Attribute: MYCO (Presence or absence of mycorrhizas) Normally absent 54 *************************** 0 Present or absent 3 63 ******************************** 4 0 Normally present 5 148 ** * * * * * * * ****** * * * * * * * * * * * ********* * * * * * * * * * ******** * * *** ** **~*** Missing values: Attribute: CANOPY (Vertical arrangement of leaf canopy) Leaves in rosette only 29 *************** 0 Leafy mostly below 3 108 ****************************************************** 4 0 Leafy at all levels 5 134 * * ****** * ** * ***** *** *** * * * * * * * *** ** ******* * * * * ** * * * * * ** *** * * ** * ** * Missing values: Attribute: BREED (Breeding system) Mainly inbreeding 1 43 ********************** 2 0 Inbr. or outbreeding 3 80 **************************************** 4 0 Mainly outbreeding 5 72 ************************************ Missing values: 78 Attribute: CANHT (Height of top of canopy) <100 mm 1 52 ************************** 100-290 mm 2 82 ***************************************** 300-990 mm 3 95 ************************************************ 1.0-2.9 m 4 32 **************** 3.0+ m 5 12 ****** Missing values: Attribute: LSIZE (Area of individual leaf) <500 1 85 ******************************************* 500-990 2 51 ************************** 1000-1900 3 51 ************************** 2000-3900 4 56 **************************** 4000+ sq mm 5 28 ************** Missing values: Attribute: DSPACE (Dispersal in space) <1 mm, wind-dispersed 1 28 ************** 2 0 Wind, water or animals 3 56 **************************** 4 0 No such dispersal 5 142 **************************************************************~*** Missing values: 47 Attribute: GINIT (Initial germinability of seed) >75 % germination 1 106 ***************************************************** 50-74 % 2 33 ***************** 25-49 % 3 18 ********* (25 % 4 42 ********************* No germination 5 63 ******************************** Missing values: 11 Attribute: GRANGE (Germination range at constant temperature) No germination 1 7 **** 4-12 deg. C 2 12 ****** 13-20 deg. C 3 60 ****************************** 21-28 deg. C 4 61 ******************************* 29+ deg. C 5 23 ************ Missing values: 110 Attribute: GDARK (Germination in darkne~:s) 90+ 1 30 *************** 50-89 % 2 49 ************************* 10-49 % 3 37 ******************* (10 % 4 35 ****************** No germination 5 27 ************** Missing values: 95 656 APPENDIX: PATIERNS OF SPECIALIZATION Attribute: GMODE (Germination mode at constant temperature) (15 1 7 **** 15-20 2 84 ****************************************** 21-25 3 55 **************************** 26-30 4 11 ****** >30 degrees c 5 2 • Missing values: 114 Attribute: SSHAPE (Seed shape, expressed as length/breadth quotient) (1. 5 1 94 *********************************************** 2 0 1. 5-2.5 3 86 ******************************************* 4 0 )2.5 5 92 ********************************************** Missing values: Attribute: SO FRT (Dispersule in the form of seed or fruit) Seed 1 92 ********************************************** 2 0 1-seeded fruit 3 162 **************************************************************~***