1.1. A group of researchers carried out bird surveys on the same farm over a period of nineteen years. Their results are shown in Table 1 below. 

Table 1

Calculate the increase in the index of diversity between 2001 and 2020 for the results shown in Table 1. 

1.2. One change in farm management that took place between 2001 and 2020 was that farm hedgerow cutting switched from a yearly cut to a staggered cut every 3 years (each hedgerow cut every 3 years, but not all cut in the same year). State how this could lead to the increase in bird diversity shown in Table 1.

1.3. Suggest what might have caused the decrease in greenfinch numbers between 2001 and 2020 shown in Table 1.  Do not include the effects of humans illegally catching greenfinches to keep as pets. 

1.4. The research shown in Table 1 above was funded by the RSPB (Royal Society for the Protection of Birds). Figure 2 below shows how the data from Table 1 compares to farm bird data from across England over the same time period.

Figure 2

Use Figure 2 to suggest why it is so important that the RSPB funds studies such as the one that provided the data for Table 1.