How past riparian management practices can affect composition and structure of vegetation for headwater ecological restoration projects

Figures & data

Figure 1. Oir River catchment area and location of study area: La Roche and Vallée aux Bergres (VAB).

Figure 2. Methodology for historical analysis of riparian landscape and Management Practice (MP) construction according to transitions between wooded (= 1) and open vegetation (meadow = 0); the five MP (A, B, C, D and E) are obtained by cluster analysis based on transitions. Transitions : 1-1 = stable wood, 0-0 = stable meadow, 0-1 = colonization by wood, 1-0 = wood cutting.

Figure 3. Management Practice Class description according transition (0 = open vegetation, 1 = riparian wood), 1-1 = stable wood; 0-0 = stable open vegetation, 0-1 = colonization by wood and 1-0 = wood cuts.

Figure 4. Riparian landscape changes according to riparian Management Practices (MP).

Table 1. GLMM results of recent and old and very old Management Practices effect on current vegetation structure and vegetation composition parameters.

	1998–2010 Recent MP effect	1979–1998 Old MP effect	1947–1979 Very old MP effect	Recent MP*brook effect
	Vegetation structure
Trunks density	<0,0001	NS	0.0237	NS
Forested linear (%)	<0,0001	NS	0.0205	NS
Small shrub cover (%)	0.0205	NS	NS	NS
Shrub cover (%)	0.0013	NS	NS	0.0363
Tree cover (%)	<0,0001	NS	NS	<0,0001
Small shrub overhang cover (%)	<0,0001	0.0279	NS	<0,0001
Shrub overhang cover (%)	NS	NS	NS	NS
Tree overhang cover (%)	<0,0001	NS	NS	<0,0001
	Vegetation composition
	Small shrub stratum
Alnus glutinosa	<0,0001	<0,0001	<0,0001	<0,0001
Corylus avellana	<0,0001	<0,0001	<0,0001	<0,0001
Salix atrocinerea	NS	<0,0001	NS	NS
Rubus sp.	<0,0001	<0,0001	<0,0001	<0,0001
Megaphorbia's plants and grass	<0,0001	<0,0001	<0,0001	<0,0001
Ferns	NS	<0,0001	<0,0001	NS
Number of ligneous species	<0,0001	NS	NS	NS
	Shrub stratum
Alnus glutinosa	0.0087	<0,0001	<0,0001	NS
Corylus avellana	<0,0001	<0,0001	<0,0001	<0,0001
Salix atrocinerea	NS	<0,0001	<0,0001	0.0214
Quercus robur	<0,0001	NS	<0,0001	<0,0001
Fraxinus excelsior	<0,0001	<0,0001	<0,0001	0.0009
Number of ligneous species	<0,0001	NS	NS	NS
	Tree stratum
Alnus glutinosa	<0,0001	<0,0001	<0,0001	<0,0001
Salix atrocinerea	<0,0001	<0,0001	<0,0001	NS
Quercus robur	<0,0001	<0,0001	<0,0001	<0,0001
Fraxinus excelsior	<0,0001	<0,0001	<0,0001	NS
Number of ligneous species	<0,0001	NS	NS	NS
Overall number of ligneous species (all strata)	<0,0001	NS	NS	NS

Table 2. Recent Management Practices effect on actual vegetation structure and vegetation composition parameters (different letters indicate significant differences in mean values).

1998–2010 Management Practice (MP)	A		B		C		D		E
	Management by grazing and mowing		Management essentially by grazing and mowing, some cuts		Mixed areas, intensive management by humans (cuts)		Intensive management by humans (cuts, maintenance), areas rather wooded		Few management, stable riparian wood
	Vegetation structure and age (mean values)
Trunks density	4.6	a	9.5	b	8.3	b	8.8	b	7.9	b
Forested linear (%)	26.8	a	50.1	b	47.1	b	43.9	b	47.1	b
Small shrub cover (%)	41.3	ab	41.9	ab	38.2	ab	31.2	a	46.4	b
Shrub cover (%)	34.4	a	62.2	b	55.1	b	56.7	b	51.3	b
Tree cover (%)	2.7	a	10.6	ab	26.1	bc	37.3	c	39.2	c
Small shrub overhang cover (%)	29.3	b	25.9	ab	15.4	ab	8.6	a	18.3	ab
Shrub overhang cover (%)	32.7	a	57.0	b	46.4	ab	46.1	ab	43.8	ab
Tree overhang cover (%)	2.0	a	6.9	a	21.9	b	27.3	b	33.6	b
Wooded patches age	2.1	a	4.3	b	9.3	c	13.4	d	19.0	e
Open patches age	40.3	d	17.9	c	12.7	b	11.4	b	6.3	a
	Vegetation composition
	Small shrub stratum (% cover mean values)
Alnus glutinosa	4.4	ab	9.9	ab	7.0	b	3.9	a	6.5	ab
Corylus avellana	0.9	a	4.9	ab	7.1	b	4.5	b	5.5	b
Salix atrocinerea	2.2	a	1.1	a	2.0	a	2.9	a	3.1	a
Rubus sp.	5.9	a	4.4	a	6.6	a	7.3	ab	14.6	b
Megaphorbia's plants and grass	26.8	b	16.3	ab	9.9	a	7.3	a	12.8	a
Ferns	1.5	a	0.9	a	2.1	a	1.8	a	3.1	a
Number of ligneous species	2.2	a	3.0	ab	3.1	b	3.5	b	3.9	b
	Shrub stratum (% cover mean values)
Alnus glutinosa	27.8	a	46.4	b	32.5	ab	24.0	a	24.9	a
Corylus avellana	1.2	a	4.7	ab	8.7	b	14.2	b	6.2	b
Salix atrocinerea	4.4	a	3.9	ab	7.0	ab	8.8	ab	11.1	b
Quercus robur	0.3	a	3.3	ab	2.6	b	2.9	b	3.3	b
Fraxinus excelsior	0.1	a	0.9	a	1.3	a	2.8	a	1.7	a
Number of ligneous species	1.3	a	2.1	ab	2.5	b	2.9	b	2.7	b
	Tree stratum (% cover mean values)
Alnus glutinosa	1.9	a	5.9	ab	15.8	bc	24.7	c	22.5	c
Salix atrocinerea	0.1	a	0.0	a	1.7	a	1.5	a	2.9	a
Quercus robur	0.7	a	4.7	ab	5.5	b	3.4	ab	7.9	b
Fraxinus excelsior	0.0	a	0.0	ab	0.9	ab	5.0	b	2.4	b
Number of ligneous species	0.1	a	0.3	a	0.9	b	1.3	b	1.2	b
Overall number of ligneous species (all strata)	2.5	a	3.6	ab	4.0	b	4.8	bc	5.1	c