Comparison of terrestrial isopod (Crustacea: Oniscidea) assemblages from two preserved areas (Bouhedma and Chambi) in arid regions

Figures & data

Table I. Characteristics of the sampling habitats in Bouhedma (Bouh 1–Bouh 3) and Chambi (Cham 1–Cham 7).

Sampling habitat	Altitude (m)	Vegetal characteristics	Soil characteristics
Bouh 1, exposed to anthropogenic impact	120	Reforestation of Eucalyptus camaldulensis, Acacia sp., palms	Sandy soil, medium and coarse
Bouh 2, open acacia savannah	190	Tree stratum formed by Acacia tortilis	Loamy soil
Bouh 3, sparse vegetation	210	Shrub layer with two Gramineae Cenchrus ciliaris, and Digitaria commutata	Sandy soil
Cham 1, sparse vegetation of halophytes	750	Atriplex and other halophytes	Sandy loam soil
Cham 2, open steppe of Stipa and Artemisia exposed to anthropogenic impact	900	Stipa tenacissima, Globularia alypum and Rosmarinus officinalis	Limestone soil
Cham 3, dense forest	1100	Aleppo pine forest, Stipa tenacissima and Rosmarinus officinalis	Rendzine ground
Cham 4, dense forest	1200	Aleppo pine forest and Juniperus phoenicea	Rendzine ground
Cham 5, dense forest	1300	Aleppo pine forest and Juniperus oxycedrus	Marl soil
Cham 6, open forest	1400	Aleppo pine forest	Marl soil
Cham 7, open maquis	1500	Maquis with green scrub, Quercus ilex and Aleppo pine	Marl soil

Figure 1. Tunisian map showing the location of the two national parks, Chambi and Bouhedma.

Table II. Temporal distribution of terrestrial isopod species in different sampling seasons in Bouhedma and Chambi parks.

	30 January 2010	26 April 2010	24 July 2010	27 October 2010	30 January 2011	26 April 2011	24 July 2011	27 October 2011	30 January 2012	28 April 2012	29 July 2012	30 October 2012
Agabiformius lentus	2	3	1	1	2	4	1	2	5	6	0	4
Leptotrichus panzerii	4	13	1	7	4	8	0	7	5	17	1	12
Porcellio laevis	0	2	1	1	0	3	0	0	3	4	1	4
Porcellio variabilis	5	9	2	7	2	9	1	3	5	18	2	11
Porcellionides pruinosus	1	4	1	1	0	6	0	2	4	7	1	5
Armadillidium sulcatum	2	5	0	1	1	3	0	1	4	7	0	3
Armadillo officinalis	0	3	0	0	2	1	0	1	3	4	0	2
Armadillidium tunisiense	7	15	2	19	9	17	4	11	15	35	1	17
Hemilepistus reaumurii	0	84	33	27	0	58	58	33	0	89	103	48
Porcellio albinus	11	28	1	24	13	17	0	15	17	46	2	28
Porcellio djahizi	14	15	2	17	6	10	1	10	15	27	2	19

(*) January = winter; April = spring; October = autumn; July = summer.

Table III. Spatial distribution of isopods in the two parks (Bouhedma and Chambi), relative abundance, and values of Shannon–Wiener (H′) and evenness indexes (J′).

Families	Species	Bouh 1 (120)	Bouh 2 (190)	Bouh 3 (210)	Cham 1 (750)	Cham 2 (900)	Cham 3 (1050)	Cham 4 1200)	Cham 5 (1300)	Cham 6 (1400)	Cham 7 (1540)	Total habitats	N1	Relative abundance (%)
Porcellionidae	A. lentus	27	3	1	0	0	0	0	0	0	0	3	31	2.52
	L. panzerii	13	5	2	0	19	25	14	0	0	0	6	78	6.37
	P. laevis	8	0	0	1	8	0	0	0	0	0	2	17	1.39
	P. variabilis	13	7	11	0	28	15	0	0	0	0	5	74	6.01
	P. pruinosus	19	0	0	1	12	0	0	0	0	0	2	32	2.60
	P. albinus	11	112	79	0	0	0	0	0	0	0	3	202	16.43
	P. djahizi	0	0	0	0	25	46	33	19	15	0	5	138	11.23
Armadillidae	A. officinalis	0	7	9	0	0	0	0	0	0	0	2	16	1.30
Agnaridae	H. reaumurii	0	0	0	523	0	0	0	0	0	0	1	523	37.59
Armadillidiidae	A. sulcatum	17	1	2	0	7	0	0	0	0	0	4	27	2.19
	A. tunisiense	0	0	0	0	13	11	39	47	26	16	6	152	12.36
	N2	108	135	104	525	112	97	86	66	41	16		1290
	S	7	6	5	3	7	4	3	2	2	1
	H’	2.68	1.06	1.28	0.04	2.64	1.78	1.47	0.86	0.94	0
	J’	0.95	0.41	0.55	0.03	0.94	0.99	0.92	0.86	0.94

Notes: N1, total number of collected individuals of the same species; N2, total number of collected individuals in the same habitat.

(*) A, Armadillidium; Ag, Agabiformius; Ar, Armadillo, H. Hemilepistus, L., Leptotrichus; P., Porcellio, Pr., Porcellionides.

Figure 2. Relationship between altitude, species richness (S) and Shannon–Wiener index (H’).

Figure 3. Multidimentional scaling plot based on species abundance. (a) season; (b) sampling habitats.

Figure 4. Canonical correspondence analysis (CCA) of isopod species, altitude and habitat type. Abbreviations: Bouh 1, 2, 3 and Cham 1, 2, 3, 4, 5, 6, 7 – habitats in Bouhedma Park and Chambi Park, respectively.