Table 1 Mean (± SE) of pH, humidity (%), organic matter (%), nitrogen (mg/Kg), phosphorus (mg/Kg), phosphatase activity (µmol/g h), β-glucosidase activity (µmol/g h) and urease activity (µmol/g h) in patches invaded and uninvaded by O. stricta under the canopies of V. nilotica and S. africana and in open patches with no tree cover.

pH

6.55

(0.05)

6.95

(0.28)

7.12

(0.15)

6.74

(0.03)

7.29

(0.22)

7.55

(0.51)

Humidity (%)

0.01^ab

(0.00)

0.01^ab

(0.00)

0.00^b

(0.01)

0.03^a

(0.00)

0.03^a

(0.00)

0.05^a

(0.02)

Organic matter (%)

1.03^ab

(0.04)

0.60^bc

(0.07)

0.31^c

(0.03)

1.00^ab

(0.20)

1.12^a

(0.11)

0.64^abc

(0.06)

Nitrogen (mg/kg)

24.00^a

(2.89)

17.33^b

(1.76)

8.33^c

(1.45)

26.33^a

(3.84)

31.33^a

(6.12)

20.33^ab

(5.84)

Phosphorus (mg/kg)

21.33^a

(1.76)

13.67^ab

(2.67)

4.33^b

(2.03)

12.67^ab

(3.84)

10.50^ab

(3.51)

16.00^ab

(4.36)

Phosphatase (µmol/g h)

2.93e−02^a

(2.97e−04)

1.93e−02^b

(3.19e−03)

6.43e−03^c

(1.53e−03)

2.10e−02^ab

(3.20e−03)

2.85e−02^a

(5.00e−04)

2.60e−02^a

(1.71e−03)

ß-glucosidase (µmol/g h)

5.17e−03^bc

(1.52e−03)

1.34e−02^a

(1.59e−03)

9.73e−03^ab

(1.23e−03)

3.88e−04^c

(3.88e−04)

1.22e−02^a

(1.63e−03)

1.18e−02^a

(1.20e−03)

Urease (µmol/g h)

3.27e−05^c

(8.15e−06)

5.15e−04^a

(7.83e−05)

1.57e−04^bc

(7.00e−06)

3.37e−05^c

(1.29e−05)

5.60e−04^a

(1.94e−05)

1.92e−04^b

(1.64e−05)