For the Agricultural Zone

Kathleen Casanova and Kaylyn Siporin

Lab 5

For the agricultural zone

• What relationships exist between farm characteristics (in the attribute table) and the percent

guava by farm?

As indicated by the graphic kcasa_A, guava coverage is related to the type of farm. As said previously, guava invasion is thought to lead to agricultural land abandonment in Isabella Island. In this instance, five out of the six farms with over 50% guava coverage, are classified as fishing or tourism type of farms. We can assume that this is a more feasible method to earn profits as opposed to compete with the agriculturally invasive guava plant.

• What, if any, proximity relationships exist between percent guava by field and (a) roads and (b)

buildings?

We decided to combine the buildings and roads because have significant effects on land cover. As indicated by kcasa_B, field proximity to roads and buildings are related to guava coverage. The lowest class of percent coverage is closest to or contains buildings and/or roads more than the other classes. It is clear that people have decided to settle in areas with little guava coverage.

• Assign each farm a category of “abandoned,” “partially abandoned,” or “active” based on percent

guava present and the farm characteristics in the attribute table. Are fields or farms next to

abandoned fields/farms more likely to contain a higher percentage of guava?

The farm fields are concentrated by like farm fields, as indicated by Kcasa_C. There is a distinct concentration of active fields in the center right of the study area. Abandon fields are mostly concentrated on the perimeter of the study area.

• Is there spatial clustering of guava in the agricultural zone or in individual fields, and does this

spatial clustering provide clues to land use practices that could affect guava distribution?

There is clustering of guava in the zones classified as having neither crops nor pasture as indicated by Kcasa_D. The areas with both pasture and crops tend to have less clustering of guava, which may explain why crops and pastures are more prevalent there.

For the Park zone

• Is there a relationship between guava in the Park and distance to the agricultural zone?

The relationship between guava number and distance is positive, in that the further you get from the farm boundaries, the smaller the guava count. We chose ten classes (1 being the closest) to show the distance from the farm. With an increase in class number, there was a decrease in class size. The attribute table is shown below in descending order of count. The fifth-tenth furthest away classes had the lowest count of guava present. See Kcasa_E for a spatial reference.

• Is there a relationship between guava distribution in the Park and percent guava in fields and farms

bordering the park?

Yes, there is a relationship between the percent guava in fields and in farms. As shown in the table below, the percent of guava and the count which represents the guava pixels located in farm fields and aggregated into farms has a relationship. The table shows count as ascending, and percent guava more or less follows that pattern, save a few outliers.

COUNT / percguava / FID_
56485 / 29.78811203100 / 8
69776 / 12.52044267380 / 12
84685 / 70.33942557950 / 4
137730 / 26.27778435710 / 14
164630 / 22.94488821500 / 11
186281 / 35.67266499220 / 1
195378 / 81.15093585590 / 13
196354 / 38.85790130300 / 6
221483 / 19.60076075070 / 2
231309 / 53.53241077830 / 5
768447 / 26.57701255240 / 3
1299019 / 64.80996464490 / 0
1709117 / 34.19454237290 / 10
2977381 / 74.40762388510 / 7
3202307 / 61.58718446110 / 15
3646255 / 49.23902863210 / 9

THE STORY

The guava invasion of the Galapagos Islands indicates a severe global change in the area. Guava is a non-native species that is cultivated in mainland Ecuador and South American for its fruit and wood. The presence of guava in the Galapagos Island is not seen as productive, as it may be in these other areas. Guava’s invasive and long lasting nature has permanently altered the native ecosystems and biodiversity in the area. Many local farmers see guava as a nuisance and it seems to lead to farm abandonment. This is supported by our findings that farms with over 50% guava coverage tend to be used for fishing or tourism purposes and not for traditional farming. And neighboring farms tend to follow suit as there are clusters of abandoned and active farms. Also, the invasion of guava has increased with simultaneously with the increase of human mobility in the area. Tourism in the Galapagos Islands compounds human population effects on the area.

Over the last decade, human land use has become increasingly related to guava invasion. This is evident by our findings shown in kcasa.b that people have decided to settle in places with less guava invasion. Places with guava invasion are less inhabited since they are often abandoned by those who used to live there.

Also, proximity relationships between municipal structures and guava are related since buildings and roads are mostly located in areas with small guava coverage.

It is evident that land use practices could have some effects on guava distributions. Our findings that fields with great amounts of guava are generally not used for agriculture support this.

The nature of our study area is very unique. The proximity of the agricultural zones and park influence the spread of guava since it is mostly concentrated closer to the farms and decreases as the distance increases from these areas.

We conclude, from our previous readings and current findings, that guava’s invasive nature negatively impacts the natural and human communities of the Galapagos Islands. These issues must be jointly solved by the public, local government, and the park services. The invasion of guava must be stopped if the Galapagos is to retain its natural beauty and diversity.