CONCEPTO DEL PRODUCTO

The computed land cover extent from 1985 to 2010 was illustrated for every 10 year period using images for the tenth year and tabulated area extent compared in square kilometres and changes in class distribution computed and compared for two subsequent dates and finally cumulative change over the period 1985‒2010. Figure 4.8 is the image for 1985 and Table 4.16 shows its class distribution.

Figure 4.8: Chepalungu Forest land cover in 1985

By 1995, the cultivated land had increased by 10% open land is significantly reduced by 2% as shown in Table 4.16 and 4.17. This is attributed to land use

activities. It is noted that there is drop in cropland by 9%. Cultivated land is on later stage under crop cover. Most importantly, 2% of open land has been consumed with no significant change in forest class.

Table 4.16: Class distribution Chepalungu Forest in 1985

Figure 4.9 of 1995 images have the class distribution shown in the Table 4.17.

Table 4.17: Class distribution in Chepalungu Forest in 1995

Changes in land use are apparently spill into the forest area triggering modification in cover. When trees outside the forest are cleared for crop planting, forest area become the alternative source of wood needed by the local people and livestock are driven into the forest for alternative pasture.

Class distribution 1985

Class Area (Km²) Percentage Forest 42.1002 13.69

Cropland 66.6153 21.66

Open land 39.0312 12.69 Cultivated land 23.7024 7.71

Class Area (Km²) Percentage

Cultivated land 53.3151 17.33 Forest 44.1522 14.36 Open land 33.7005 10.96 Cropland 40.2822 13.10

Cutting and browsing therefore create gaps in forest cover. The table indicate 44.25% other classes which was not among the defined.

Figure 4.9: Chepalungu Forests land cover in 1995

Table 4.18 indicates detected changes within the 1985 and 1995. The significant change in the forest area is 5% decrease with the largest proportion lost to open land in a 3% decrease meaning tree cover outside forest is decreasing at the same time gaps in forest are widening.

Table 4.18: Area (Square Km) change detection 1985‒1995 F inal st ate F inal st ate Initial state

Class Cultivated land Forest Open land Cropland

Unclassified 0.00 0.00 0.00 0.00 No data 0.02 0.01 0.03 0.05 Cultivated land 11.61 0.41 13.98 27.27 Forest 0.03 39.89 3.57 0.65 Open land 4.21 1.47 14.16 13.84 Cropland 7.84 0.32 7.29 24.81 Class Total 23.70 42.10 39.03 66.62 Class Changes 12.10 2.21 24.88 41.80

The change detected in this period Table 4.19 indicates 51% of cultivated land changing into other classes with the largest share being conversions to cropland by 33 %, the forest land-class loss is 5 % whereby its large proportion into open land is attributed to clearing / logging. Open land changed by 64% reducing 36% to cultivated land. On the other hand, cropland change is 63 % largely 41% into cultivated land.

Table 4.19: Change detection percentage 1985‒1995 F inal S tate of C lasse s F inal st ate

Initial State of Classes

Class Cultivated Forest Open land Cropland

Unclassified 0.000 0.000 0.000 0.000 No data 0.084 0.015 0.076 0.069 Cultivated 48.963 0.964 35.810 40.930 Forest 0.140 94.756 9.159 0.977 Open land 17.748 3.495 36.269 20.779 Cropland 33.065 0.770 18.687 37.245 Class Total 100.000 100.00 100.000 100.00 Class changes 51.037 5.244 63.731 62.755

Figure 4.10 displays a lot of opening in the forest area following clear-cut, cropland and open land have increased as shown in Table 4.20 compared to previous year on Table 4.17. Increase in openings implies acute degradation in forest and class changes in table 4.19 vigorous human activities causing degradation at increasing rate. Replanting of in situ trees is needed to mitigate ecosystem change. Use environmental friendly crop production methods like sericulture and encourage on-farm forestry.

Table 4.20: Class distribution of Chepalungu Forest land cover in 2005

Figure 4.10: Chepalungu Forest extent in 2005

Table 4.21 shows changes in percentage of the final state with respect to the initial state of the 1995–2005.

Class distribution 2005

Class Percentage Area (Km²) Forest 11.255 34.6158 Cultivated land 16.40 50.4477 Cropland 15.12 46.5147 Open land 12.94 39.807

Table 4.21: Change detection statistics 1995 – 2005 percentage

The class loss in forest is at 24% with high of 12% to open land. The cultivated land, about 61% change where largely 29% to open land. Croplands changed by 50% equally into cultivated land and open and cultivated land in a 25% loss. Open land changed by 74% losing 46% to cultivated land.

Figure 4.11 is the 2010 land cover from which the class distributions shown in Table 4.22 are identified. The gaps noticed earlier in the forest cover of 2005 are now with vegetation as cropland and cultivated land are reduced in area.

Fi

n

al

s

ta

te

Initial state

Class Forest Cultivated Cropland Open land

Forest 76.112 0.483 0.543 1.578 Cultivated land 8.859 39.351 24.624 46.268 Cropland 2.778 30.753 50.147 25.723 Open land 12.239 29.265 24.628 26.292 Class Total 100 100 100 100 Class Changes 23.888 60.649 49.853 73.708

Figure 4.11: Chepalungu Forest land cover in 2010

Table 4.22: Class distribution Chepalungu Forest land cover in 2010

Class distribution 2010

Class Percentage Area (Km²)

Forest 22.91 70.4610

Cultivated land 5.75 17.6940

Open land 19.54 60.0858

As indicated in Table 4.23, the forest area decreased by 5 % of which 3% is attributed to open land and is the largest loss during this time. Cultivated land changed by 46% into open land, open land by 41% into forest land Cropland on the other hand receded by 66% with a large portion of 47% to open land.

Table 4.23: Change detection statistics percentages 2005 – 2010

F inal st ate of land c ove r classe s

Initial State of land cover classes

Class Forest Cultivated Open land Cropland

Forest 95.424 32.833 40.918 9.709 Cultivated land 0.458 12.708 16.665 9.591 Open land 3.315 45.951 34.454 47.143 Cropland 0.803 8.508 7.963 33.556 Class total 100 100 100 100 Class Changes 4.576 87.292 65.546 66.444

The change in forest class shown in Table 4.24 is relatively low compared to other classes with a lion share to open land in 1.15%. When a forest is opened, its vegetation characteristics are affected. These changes evaluated here are over a period of 25 years of class interaction to provide a basis for the ultimate conclusion on the impact of such interaction in our study area. The forest changed by 9% losing the largest proportion to open land by 7% which is attributed to logging and clearing. There is contribution to forest land by open land in the continued planting of trees in the forest neighbourhood.

Table 4.24: Change detection statistics Area (sq. km.) of land cover classes 2005 – 2010 F inal st ate land c ove r cla sses F inal st ate

Initial state of land cover classes

Class Forest Cultivated land Open land Cropland

Forest 33.03 16.56 16.29 4.52 Cultivated land 0.16 6.41 6.63 4.46 Open land 1.15 23.18 13.72 21.93 Cropland 0.28 4.29 3.17 15.61 Class Total 34.62 50.45 39.81 46.51 Class Changes 1.58 44.04 26.09 30.91

Figure 4.12 give a clear view of encroachment into the forest along its perimeter. The images of the years under consideration have been overlaid. The most affected points A and B at Kipirir fragment and in Siongiroi fragment at points D to F. It is vivid that forest gaps which were not prevalent in 2005 at Kipirir Forest were expansive in 2010.

Figure 4.12: Forest change map in Chepalungu Forest 1985‒2010

Source: Fieldwork (2013).

The change in class statistics in Table 4.25 over the 25-year period indicate the forest decreased by 9% which is quite significant ecologically as it implies loss of biodiversity. The largest is to the open land class with 7% of the total change. This directly means that the major forest change agent is human interference by overexploitation of forest resource. Poor farmers use forest diversity as part of the risk management strategies, when crop harvest fail, people often turn to forests and trees for supplementing food and income and for mitigating hunger and malnutrition (Trapnell, 1997). The forest being relatively unprotected is bound to lose its biomass. The change in area is provided in square kilometres in Table 4.26.

Table 4.25: Change detection statistics percentages 1985 – 2010 F inal st ate of land c ove r classe s F inal S tate

Initial state of land cover classes

Class Forest Cultivated Open land Cropland

Unclassified 0 0 0 0 No data 0 0 0 0 Forest 91.265 14.493 32.508 23.836 Cultivated land 0.763 19.373 11.077 12.657 Open land 6.578 47.107 44.644 43.005 Cropland 1.394 19.027 11.771 20.502 Class Total 100 100 100 100 Class Changes 8.735 80.627 55.356 79.498

The forest has since changed in area by a margin of 8% which is quite a significant loss in a forest which is barely, 50 sq. km and this rate is alarming. In 25 years‟ time, it may reduce by 20% of the total area if no conservative measures are undertaken. As noted earlier, the single biggest contributor is the open land at 7%. This leads to the conclusion that the forest reserve is facing real time effects of human activities responsible for this change detected.

Table 4.26: Change detection statistics area (sq. Km) 1985‒2010 F inal st ate of land c ove r classe s

Initial State of land cover classes

Class Forest Cultivated Open land Cropland

Unclassified 0.00 0 0 0 No data 0.00 0 0 0 Forest 3.84 3.44 12.69 15.88 Cultivated 32.00 4.59 4.32 8.43 Open land 2.77 11.17 17.42 28.65 Cropland 0.59 4.51 4.59 13.66 Class Total 42.1 23.7 39.03 66.62 Class Changes 3.68 19.11 21.61 52.96 Disturbance Observation

To examine further the human activities which bring about disturbance, the researcher observed the plant foliage to notice what leads to its state and found that cutting, browsing and trampling were apparent then took record as they occur in every quadrat in a summary in Tables 4.27,4.28, and 4.29.

Indicated in Table 4.27, indicated that cutting of vegetation was the most prevalent form of disturbance occurring in the forest core compared to trampling and browsing by animals.

Table 4.27: Observed disturbance in the core of Chepalungu Forest

Table 4.28, indicates that cutting is predominant. This was carried out by human agents. Browsing rose to 21% given that this was the zone with highest diversity so that palatable species are available for browsers while trampling by large grazers could explain resource partitioning in ecological niche.

Table 4.28: Observed disturbance in the middle of Chepalungu Forest

Table 4.29 shows that at the edge of the forests, the main disturbance on vegetation is cutting with 81% while browsing is significantly reduced due to the fact that the edge is dominated by non-palatable species Acokanthera schimperi and Teclea simplicifolia.

Disturbance Frequency Percentage

Cutting 17 73.9

Trampling 4 7.4

Browsing 2 8.7

Total 23 100

Disturbance Frequency Percentage Cutting Trampling Browsing 130 30 43 64.0 14.8 21.2 Total 20 3 100

Table 4.29: Observed disturbance at the Chepalungu Forest edge

he prevalent disturbance based on onsite observation was the used charcoal earth mounds in approximate radius of 5 m. Old pits were already grown by ephemerals while fresh ones remained bare as in Plate 4.6 and 4.7.

Plate 4.6: Exposed fresh charcoal mounds in Chepalungu Forest

Disturbance Frequency Percentage

Cutting 192 81.0 Trampling 36 15.2 Browsing 9 3.8

Total 237 100

Plate 4.7: Charcoal making disturbance with immature tree logs of Chepalungu forest

Charcoal making leaves gaps in the forest. These spots have average radius of 5 m and exterminate rare species while reducing ecosystem complexity. Clear cutting and felling are disturbances found at the forest edge.

Plate 4.8: Women carrying firewood from Chepalungu Forest during interview.

As indicated in Plate 4.8, firewood collection is pointed out as a major factor in the degeneration of trees through constant chopping and pruning which limits vertical height of trees. Species which would otherwise regenerate through vegetative buds are axed and stumps uprooted a further loss to ecological significance of decaying wood. Cutting which accounts for 73%, 64% and 81% disturbance forms in Tables 4.27, 4.28, and 4.29 is a means through which firewood is collected.

Plate 4.9: Goats browsing Chepalungu Forest bushes in the middle zone

Plate 4.10: Goats browsing on plants at the edge Chepalungu Forest.

This study found that browsing as shown in Plate 4.9 and 4.10 is a form of disturbance on vegetation occurring in frequencies displayed in Tables 4.27, 4.28, and 4.29. Vegetation through the process of interacting with browser

12/9/2013

majorly the goats, among other livestock in the forest neighbourhood, inhibits the vegetative ability of plants to reach maturity.

Plate 4.11 shows trampling by livestock which create a form of disturbance by opening up the forest, exposure to erosion and constant abrasion which hamper growth of plants.

Plate 4.11: Cattle trampling on vegetation in the Chepalungu Forest

The paths constantly used by livestock continually degrading with time and the vegetation trampled on are barred from their productivity. These paths in plate 4.11 and statistics shown in Tables 4.27, 4.28, and 4.29 are noted to contribute to poor vegetation vigor. Paths used by human and livestock are in webbing network design. It gives room for more incident solar radiation to

reach the ground and modify micro conditions. Decaying wood for instant is important habitat for bacterial and fungal life essential in ecological processes in forest floors and could be halted by exposure to too much sun radiation.

Plate 4.12: A wet area of Chepalungu Forest middle zone burnt

Forest burning is a form of disturbance which leaves a patch of ecosystem bare and potentially degrading outside natural forest fires or otherwise regulated incidence. This research found that the bush burning was on a marshy area within the forest in Plate 4.12. This indicates that the water ways remain dry in most part of the year.

As indicated in Plate 4.13, logging is believed to take away mature trees for the most valuable wood products such as poles, timber, charcoal, and

firewood. Mature trees are responsible species continuity by reproducing beside other ecosystem roles. The felling of mature trees in natural forest is inevitably destructive process, which as has been pointed out, is going to have drastic effects on the ecosystem and the flora, with the resultant dense secondary vegetation growth impeding natural vegetation. Without natural regeneration of the exploited species no form of management can be postulated as sustainable and degradation is inevitable (Trapnell, 1997).

Plate 4.13: Logging stump in Chepalungu Forest core

4.3.1 Hypothesis Testing for Human Activities and Vegetation Characteristics

This study had hypothesized that there is no relationship between human activities taking place in the forest and the vegetation characteristics. The responses to the destructive activities as cases were subjected to chi-square operation to establish any significant difference in the rating of the destructiveness of these activities and if they are really destroying the forest.

This is carried out with the assumption that by respondents rating any of the activities very destructive or otherwise does not affect the subsequent events rating as in Table 4.30. The expected value was derived from the mean of the cases representing tendencies from very destructive to least destructive.

Table 4.30: Destructive activities rating in Chepalungu Forest Activity Observed (O)Expected(E)

Charcoal burning 193 168 Logging 168 168 Browsing 148 168 Cultivation 135 168 Bee keeping 191 168 Herb collection 182 168 Trampling 164 168 Grazing 159 168

Table 4.31: Chi-square results of destructive activities rating in Chepalungu Forest

Calculated value χ² 17.48 Decrees of freedom 7 Critical value at 0.5 14.1

On considering that the calculated value is larger than the table value at 0.5 critical level and 7 decrees of freedom, the H0 was rejected and concluded that the human activities known to take place in Chepalungu Forest in reality destroys the forest.