## Loading required package: readxl
## Loading required package: lubridate
## 
## Attaching package: 'lubridate'
## The following objects are masked from 'package:data.table':
## 
##     hour, isoweek, mday, minute, month, quarter, second, wday, week,
##     yday, year
## The following objects are masked from 'package:base':
## 
##     date, intersect, setdiff, union
## Loading required package: solartime
## - Winter data excluded.
## - The counts of all passing / wintering species (not breeding in the sampled unit) were set to zero. Abreed_and_non_breed contains the non-breeders as well.
## - Species less likely to be interacting with sampling location were EXCLUDED
## - observations with counts greater than or equal to 10 standard deviations AND greater than or equal to 60 individuals were set to 1,
## under the assumption that these are migrating or local wandering phenomena.
## No outliers found in unit Arid South.
## 2 outliers set equal to 1 in Herbaceous and Dwarf-Shrub Vegetation unit.
##                                     unit    point_name year
## 1: Herbaceous and Dwarf-Shrub Vegetation  Gamla Near 3 2014
## 2: Herbaceous and Dwarf-Shrub Vegetation Yavneel Far 2 2018
##                  SciName count_under_250  Z_score
## 1:     Passer domesticus              62 11.90316
## 2: Passer hispaniolensis              60 11.35733
## No outliers found in unit Inland Sands.
## No outliers found in unit Loess Covered Areas in the Northern Negev.
## No outliers found in unit Mediterranean-Desert Transition Zone.
## 5 outliers set equal to 1 in Mediterranean Maquis unit.
##                    unit           point_name year             SciName
## 1: Mediterranean Maquis     Beit Oren Near 1 2019     Curruca curruca
## 2: Mediterranean Maquis     Beit Oren Near 3 2019     Curruca curruca
## 3: Mediterranean Maquis Kerem Maharal Near 3 2021     Chloris chloris
## 4: Mediterranean Maquis Kerem Maharal Near 3 2021 Garrulus glandarius
## 5: Mediterranean Maquis    Nir Etzion Far 11 2021       Columba livia
##    count_under_250  Z_score
## 1:              99 11.94535
## 2:             142 17.16927
## 3:              80 19.19266
## 4:             150 20.50138
## 5:             100 14.85118
## 2 outliers set equal to 1 in Negev Highlands unit.
##               unit           point_name year                  SciName
## 1: Negev Highlands  Yeruham Far Slope 5 2018 Carpospiza brachydactyla
## 2: Negev Highlands Bislach Near Slope 6 2020    Passer hispaniolensis
##    count_under_250  Z_score
## 1:              70 14.34802
## 2:             100 10.61343
## No outliers found in unit Planted Conifer Forest.

Negev Highlands

Factors are proximity to settlements, habitat (slope vs. wadi but only far from settlements, near has only slope) and time.

5 sites with 9 plots per site (3 for each habitat X proximity combination).

Total 5 campaigns, one of which is pilot in the year 2012. No sampling was performed in the Wadi habitat during the pilot.

Raw data Total abundance: 7597 Number of observations: 2111 Total richness: 108

Filtered data Total abundance: 3735 Number of observations: 1095 Total richness: 48

Model gma, abundance and richness

Richness done with rare species. Abundance and mean abundance done without rare species. Full models include cosine and sine of the time difference from June 21st (in radians).

richness

Explore data.

## [1] "RICHNESS WITH RARE SPECIES"
richness year_ct site settlements habitat td_sc cos_td_rad sin_td_rad h_from_sunrise cos_hsun sin_hsun monitors_name wind precipitation temperature clouds
Min. : 1.000 Min. :0.000 Sde Boker:42 Far :134 Slope:150 Min. :-1.60666 Min. :0.004304 Min. :-1.0000 Length:210 Min. :0.2054 Min. :-0.2965 Eyal Shochat: 41 0 : 0 0 : 0 0 : 0 0 : 0
1st Qu.: 3.000 1st Qu.:2.000 Yeruham :42 Near: 76 Wadi : 60 1st Qu.:-1.22035 1st Qu.:0.177649 1st Qu.:-0.9841 Class :difftime 1st Qu.:0.7812 1st Qu.: 0.1758 Other : 4 1 : 0 3 : 0 1 : 0 1 : 0
Median : 5.000 Median :4.000 Bislach :36 NA NA Median :-0.76251 Median :0.375715 Median :-0.9267 Mode :numeric Median :0.9157 Median : 0.4019 Adi Domer : 0 2 : 0 NA’s:210 2 : 0 2 : 0
Mean : 5.214 Mean :4.286 Ezuz :36 NA NA Mean :-0.47356 Mean :0.440753 Mean :-0.8039 NA Mean :0.8356 Mean : 0.4129 Asaf Mayrose: 0 3 : 0 NA 3 : 0 3 : 0
3rd Qu.: 7.000 3rd Qu.:6.000 Merhav Am:36 NA NA 3rd Qu.: 0.07211 3rd Qu.:0.690173 3rd Qu.:-0.7236 NA 3rd Qu.:0.9813 3rd Qu.: 0.6242 Eliraz Dvir : 0 NA’s:210 NA NA’s:210 NA’s:210
Max. :15.000 Max. :8.000 Ashalim : 6 NA NA Max. : 2.97181 Max. :0.999407 Max. : 0.4787 NA Max. :1.0000 Max. : 0.9787 (Other) : 0 NA NA NA NA
NA NA (Other) :12 NA NA NA NA NA NA NA’s :75 NA’s :75 NA’s :165 NA NA NA NA

no observation for all 4 weather variables. many NAs for sampling time of day variables.exclude from model.

## Warning in cor(P.anal[, lapply(X = .SD, FUN = as.numeric), .SDcols =
## IVs[1:12]], : the standard deviation is zero
richness year_ct site settlements habitat td_sc cos_td_rad sin_td_rad h_from_sunrise cos_hsun sin_hsun monitors_name
richness 1.0000000 0.0103577 -0.0002292 0.4194268 0.0539383 0.2521594 0.2664592 0.2251954 0.0857425 0.0187119 0.1234390 0.1890127
year_ct 0.0103577 1.0000000 -0.0195456 -0.0866957 0.1666667 -0.2769423 -0.2743588 -0.2470754 -0.2130095 0.1769441 -0.2089485 NA
site -0.0002292 -0.0195456 1.0000000 -0.0050223 -0.0078182 0.0012529 0.0254386 -0.0200397 -0.0591920 0.0649672 -0.0532192 -0.2739469
settlements 0.4194268 -0.0866957 -0.0050223 1.0000000 -0.4763042 -0.0578505 -0.0886498 -0.0259035 0.1001375 0.0051981 0.1351982 0.1104315
habitat 0.0539383 0.1666667 -0.0078182 -0.4763042 1.0000000 0.0393762 0.0463499 0.0369900 0.0339170 -0.0318150 0.0277413 0.1104315
td_sc 0.2521594 -0.2769423 0.0012529 -0.0578505 0.0393762 1.0000000 0.9677863 0.9679062 0.0805063 -0.0915903 0.0697040 0.0466138
cos_td_rad 0.2664592 -0.2743588 0.0254386 -0.0886498 0.0463499 0.9677863 1.0000000 0.8777655 0.0850144 -0.0994639 0.0727109 0.0666735
sin_td_rad 0.2251954 -0.2470754 -0.0200397 -0.0259035 0.0369900 0.9679062 0.8777655 1.0000000 0.0797859 -0.0800387 0.0732132 -0.0344973
h_from_sunrise 0.0857425 -0.2130095 -0.0591920 0.1001375 0.0339170 0.0805063 0.0850144 0.0797859 1.0000000 -0.9348973 0.9913101 0.0672842
cos_hsun 0.0187119 0.1769441 0.0649672 0.0051981 -0.0318150 -0.0915903 -0.0994639 -0.0800387 -0.9348973 1.0000000 -0.8826232 0.0115382
sin_hsun 0.1234390 -0.2089485 -0.0532192 0.1351982 0.0277413 0.0697040 0.0727109 0.0732132 0.9913101 -0.8826232 1.0000000 0.0810296
monitors_name 0.1890127 NA -0.2739469 0.1104315 0.1104315 0.0466138 0.0666735 -0.0344973 0.0672842 0.0115382 0.0810296 1.0000000

Fit Poisson glm, check for existence of overdispersion

## [1] "Estimating overdispersion parameter phi: (Res. Dev.)/(n-p) where n=number of observations; p=number of parameters in the model."
## [1] "od = 0.917237513515559"

Overdispersion parameter is < 1. Poisson more appropriate. Compare Poisson and negative binomial.

## Warning in theta.ml(Y, mu, sum(w), w, limit = control$maxit, trace =
## control$trace > : iteration limit reached

## Warning in theta.ml(Y, mu, sum(w), w, limit = control$maxit, trace =
## control$trace > : iteration limit reached
##       df      AIC
## m0.po 15 898.0002
## m0.nb 16 900.0029
## [1] "poisson"

## [1] "neg bin"

negative binomial did not converge due to underdispersion.

## Warning in checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv, :
## Model failed to converge with max|grad| = 0.00255536 (tol = 0.002, component 1)

mixed model did not converge. go with glm.

## 
## Call:
## glm(formula = richness ~ settlements * year_ct + habitat * year_ct + 
##     cos_td_rad + sin_td_rad + site, family = poisson, data = P.anal)
## 
## Deviance Residuals: 
##      Min        1Q    Median        3Q       Max  
## -2.24407  -0.67956  -0.09001   0.43547   2.90185  
## 
## Coefficients:
##                          Estimate Std. Error z value Pr(>|z|)    
## (Intercept)              0.824194   0.403615   2.042   0.0411 *  
## settlementsNear          0.522044   0.132989   3.925 8.66e-05 ***
## year_ct                 -0.008411   0.024016  -0.350   0.7262    
## habitatWadi              0.340126   0.177333   1.918   0.0551 .  
## cos_td_rad               0.589455   0.255940   2.303   0.0213 *  
## sin_td_rad              -0.100095   0.257286  -0.389   0.6972    
## siteBislach              0.082076   0.229625   0.357   0.7208    
## siteEzuz                 0.195652   0.227413   0.860   0.3896    
## siteMashabei Sadeh       0.143101   0.267942   0.534   0.5933    
## siteMerhav Am            0.185915   0.227452   0.817   0.4137    
## siteMitzpe Ramon         0.057565   0.272391   0.211   0.8326    
## siteSde Boker           -0.035671   0.226967  -0.157   0.8751    
## siteYeruham              0.201637   0.218949   0.921   0.3571    
## settlementsNear:year_ct  0.031812   0.027164   1.171   0.2416    
## year_ct:habitatWadi      0.015152   0.034139   0.444   0.6572    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for poisson family taken to be 1)
## 
##     Null deviance: 262.91  on 209  degrees of freedom
## Residual deviance: 154.64  on 195  degrees of freedom
## AIC: 898
## 
## Number of Fisher Scoring iterations: 4

perform stepwise model selection of poisson glm.

## Start:  AIC=898
## richness ~ settlements * year_ct + habitat * year_ct + cos_td_rad + 
##     sin_td_rad + site
## 
##                       Df Deviance    AIC
## - site                 7   162.28 891.63
## - sin_td_rad           1   154.80 896.15
## - year_ct:habitat      1   154.84 896.20
## - settlements:year_ct  1   156.02 897.37
## <none>                     154.64 898.00
## - cos_td_rad           1   160.11 901.47
## 
## Step:  AIC=891.63
## richness ~ settlements + year_ct + habitat + cos_td_rad + sin_td_rad + 
##     settlements:year_ct + year_ct:habitat
## 
##                       Df Deviance    AIC
## - year_ct:habitat      1   162.34 889.70
## - settlements:year_ct  1   163.53 890.88
## - sin_td_rad           1   164.27 891.62
## <none>                     162.28 891.63
## - cos_td_rad           1   176.30 903.66
## 
## Step:  AIC=889.7
## richness ~ settlements + year_ct + habitat + cos_td_rad + sin_td_rad + 
##     settlements:year_ct
## 
##                       Df Deviance    AIC
## - settlements:year_ct  1   163.70 889.06
## <none>                     162.34 889.70
## - sin_td_rad           1   164.41 889.77
## - cos_td_rad           1   176.41 901.76
## - habitat              1   187.12 912.47
## 
## Step:  AIC=889.06
## richness ~ settlements + year_ct + habitat + cos_td_rad + sin_td_rad
## 
##               Df Deviance    AIC
## - sin_td_rad   1   165.69 889.05
## <none>             163.70 889.06
## - year_ct      1   165.83 889.19
## - cos_td_rad   1   177.94 901.30
## - habitat      1   187.40 910.76
## - settlements  1   242.07 965.42
## 
## Step:  AIC=889.05
## richness ~ settlements + year_ct + habitat + cos_td_rad
## 
##               Df Deviance    AIC
## <none>             165.69 889.05
## - year_ct      1   168.04 889.40
## - habitat      1   188.85 910.21
## - cos_td_rad   1   191.61 912.97
## - settlements  1   242.24 963.59

keep removing terms because \(\Delta AIC<2\). remove year.

## Single term deletions
## 
## Model:
## richness ~ settlements + habitat + cos_td_rad
##             Df Deviance    AIC
## <none>           168.04 889.40
## settlements  1   243.91 963.27
## habitat      1   193.59 912.94
## cos_td_rad   1   191.62 910.98

final model includes settlements, habitat, sampling time of year. Final model:

## 
## Call:
## glm(formula = richness ~ settlements + habitat + cos_td_rad, 
##     family = poisson, data = P.anal)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -2.1269  -0.6569  -0.0935   0.4146   3.1465  
## 
## Coefficients:
##                 Estimate Std. Error z value Pr(>|z|)    
## (Intercept)      1.03876    0.07902  13.146  < 2e-16 ***
## settlementsNear  0.64592    0.07608   8.490  < 2e-16 ***
## habitatWadi      0.41693    0.08281   5.035 4.78e-07 ***
## cos_td_rad       0.48810    0.09977   4.892 9.98e-07 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for poisson family taken to be 1)
## 
##     Null deviance: 262.91  on 209  degrees of freedom
## Residual deviance: 168.05  on 206  degrees of freedom
## AIC: 889.4
## 
## Number of Fisher Scoring iterations: 4

Observations 210
Dependent variable richness
Type Generalized linear model
Family poisson
Link log
χ²(3) 94.868
Pseudo-R² (Cragg-Uhler) 0.367
Pseudo-R² (McFadden) 0.097
AIC 889.402
BIC 902.790
exp(Est.) 2.5% 97.5% z val. p
(Intercept) 2.826 2.420 3.299 13.146 0.000
settlementsNear 1.908 1.643 2.215 8.490 0.000
habitatWadi 1.517 1.290 1.785 5.035 0.000
cos_td_rad 1.629 1.340 1.981 4.892 0.000
Standard errors: MLE

## [1] 90.77338

## [1] 51.72905

statistically significant higher richness near settlements and in the wadi compared to slope. No significant temporal trend.

Near plots have on average 3.1806487 more species than far plots, which is 90.773377 percent higher. Wadi plots have on average 1.8125573 more species than far plots, which is 51.7290533 percent higher.

geometric mean of abundance

Explore data. Exclude time of day because of high number of NAs.

## [1] "GEOMETRIC MEAN ABUNDANCE WITHOUT RARE SPECIES"
gma year_ct site settlements habitat td_sc cos_td_rad sin_td_rad
Min. :1.000 Min. :0.000 Sde Boker:42 Far :134 Slope:150 Min. :-1.60666 Min. :0.004304 Min. :-1.0000
1st Qu.:1.644 1st Qu.:2.000 Yeruham :42 Near: 76 Wadi : 60 1st Qu.:-1.22035 1st Qu.:0.177649 1st Qu.:-0.9841
Median :2.142 Median :4.000 Bislach :36 NA NA Median :-0.76251 Median :0.375715 Median :-0.9267
Mean :2.395 Mean :4.286 Ezuz :36 NA NA Mean :-0.47356 Mean :0.440753 Mean :-0.8039
3rd Qu.:2.884 3rd Qu.:6.000 Merhav Am:36 NA NA 3rd Qu.: 0.07211 3rd Qu.:0.690173 3rd Qu.:-0.7236
Max. :9.898 Max. :8.000 Ashalim : 6 NA NA Max. : 2.97181 Max. :0.999407 Max. : 0.4787
NA NA (Other) :12 NA NA NA NA NA

Exclude outlier plot with gma of nearly 10, from Ezuz Near Slope 11 2016-03-23. Richness of 4 and abundance of 61 (40 of which are house sparrow). Fit glm, compare gamma, gaussian (poisson inappropriate because response is not discrete)

Gamma seems better than gaussian. Fit fixed and mixed models.

## Warning in checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv, :
## Model failed to converge with max|grad| = 0.066625 (tol = 0.002, component 1)

Mixed model did not converge, use glm:

## 
## Call:
## glm(formula = gma ~ settlements * year_ct + habitat * year_ct + 
##     cos_td_rad + sin_td_rad + site, family = Gamma, data = P.anal)
## 
## Deviance Residuals: 
##      Min        1Q    Median        3Q       Max  
## -0.73450  -0.30596  -0.06747   0.17704   1.35814  
## 
## Coefficients:
##                          Estimate Std. Error t value Pr(>|t|)    
## (Intercept)              0.894883   0.147782   6.055 7.12e-09 ***
## settlementsNear         -0.225280   0.046072  -4.890 2.11e-06 ***
## year_ct                 -0.009126   0.008079  -1.130  0.26001    
## habitatWadi             -0.120965   0.067159  -1.801  0.07323 .  
## cos_td_rad              -0.229967   0.094345  -2.438  0.01569 *  
## sin_td_rad               0.165542   0.091706   1.805  0.07260 .  
## siteBislach             -0.130512   0.087961  -1.484  0.13950    
## siteEzuz                -0.231613   0.085237  -2.717  0.00718 ** 
## siteMashabei Sadeh      -0.102513   0.098209  -1.044  0.29787    
## siteMerhav Am           -0.112233   0.087904  -1.277  0.20321    
## siteMitzpe Ramon        -0.159833   0.092136  -1.735  0.08437 .  
## siteSde Boker           -0.135849   0.085501  -1.589  0.11372    
## siteYeruham             -0.104415   0.084732  -1.232  0.21933    
## settlementsNear:year_ct  0.024836   0.009358   2.654  0.00862 ** 
## year_ct:habitatWadi      0.026204   0.013000   2.016  0.04520 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for Gamma family taken to be 0.1451561)
## 
##     Null deviance: 34.538  on 208  degrees of freedom
## Residual deviance: 25.286  on 194  degrees of freedom
## AIC: 512.1
## 
## Number of Fisher Scoring iterations: 5

perform stepwise model selection of Gamma model.

## Start:  AIC=512.1
## gma ~ settlements * year_ct + habitat * year_ct + cos_td_rad + 
##     sin_td_rad + site
## 
##                       Df Deviance    AIC
## <none>                     25.286 512.10
## - sin_td_rad           1   25.817 513.76
## - year_ct:habitat      1   25.877 514.18
## - cos_td_rad           1   26.213 516.49
## - site                 7   28.051 517.15
## - settlements:year_ct  1   26.316 517.20

Keep dropping terms because \(\Delta AIC<2\). drop sine.

## Single term deletions
## 
## Model:
## gma ~ settlements * year_ct + habitat * year_ct + cos_td_rad + 
##     site
##                     Df Deviance    AIC
## <none>                   25.817 514.53
## cos_td_rad           1   26.259 515.50
## site                 7   28.257 516.88
## settlements:year_ct  1   26.832 519.33
## year_ct:habitat      1   26.395 516.41

drop cosine.

## Single term deletions
## 
## Model:
## gma ~ settlements * year_ct + habitat * year_ct + site
##                     Df Deviance    AIC
## <none>                   26.259 516.16
## site                 7   28.468 517.10
## settlements:year_ct  1   27.298 521.19
## year_ct:habitat      1   26.902 518.51

drop site.

## Single term deletions
## 
## Model:
## gma ~ settlements * year_ct + habitat * year_ct
##                     Df Deviance    AIC
## <none>                   28.468 519.40
## settlements:year_ct  1   29.545 524.43
## year_ct:habitat      1   29.349 523.15

Settlements * year and habitat * year remain. This is the final model:

## 
## Call:
## glm(formula = gma ~ settlements * year_ct + habitat * year_ct, 
##     family = Gamma, data = P.anal)
## 
## Deviance Residuals: 
##      Min        1Q    Median        3Q       Max  
## -0.79797  -0.27674  -0.07058   0.20624   1.41435  
## 
## Coefficients:
##                          Estimate Std. Error t value Pr(>|t|)    
## (Intercept)              0.524412   0.040233  13.035  < 2e-16 ***
## settlementsNear         -0.222319   0.047258  -4.704  4.7e-06 ***
## year_ct                 -0.010785   0.007711  -1.399  0.16344    
## habitatWadi             -0.152894   0.067549  -2.263  0.02467 *  
## settlementsNear:year_ct  0.025386   0.009598   2.645  0.00881 ** 
## year_ct:habitatWadi      0.031540   0.013190   2.391  0.01770 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for Gamma family taken to be 0.1533962)
## 
##     Null deviance: 34.538  on 208  degrees of freedom
## Residual deviance: 28.468  on 203  degrees of freedom
## AIC: 519.4
## 
## Number of Fisher Scoring iterations: 5

Fit also a model without interaction to understand whether there is a general trend in GMA:

## 
## Call:
## glm(formula = gma ~ settlements + habitat + year_ct, family = Gamma, 
##     data = P.anal)
## 
## Deviance Residuals: 
##      Min        1Q    Median        3Q       Max  
## -0.74325  -0.30483  -0.06355   0.19569   1.18267  
## 
## Coefficients:
##                  Estimate Std. Error t value Pr(>|t|)    
## (Intercept)      0.448039   0.026822  16.704  < 2e-16 ***
## settlementsNear -0.122927   0.026977  -4.557 8.92e-06 ***
## habitatWadi     -0.016436   0.032469  -0.506   0.6133    
## year_ct          0.007960   0.004186   1.901   0.0586 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for Gamma family taken to be 0.1524776)
## 
##     Null deviance: 34.538  on 208  degrees of freedom
## Residual deviance: 29.806  on 205  degrees of freedom
## AIC: 525.23
## 
## Number of Fisher Scoring iterations: 5

Overall temporal trend in GMA is not significant. So is difference in GMA between wadi and slope (but significant for settlement proximity).

Observations 209
Dependent variable gma
Type Generalized linear model
Family Gamma
Link inverse
χ²(5) 6.07
Pseudo-R² (Cragg-Uhler) 0.19
Pseudo-R² (McFadden) 0.08
AIC 519.40
BIC 542.80
Est. S.E. t val. p
(Intercept) 0.52 0.04 13.03 0.00
settlementsNear -0.22 0.05 -4.70 0.00
year_ct -0.01 0.01 -1.40 0.16
habitatWadi -0.15 0.07 -2.26 0.02
settlementsNear:year_ct 0.03 0.01 2.64 0.01
year_ct:habitatWadi 0.03 0.01 2.39 0.02
Standard errors: MLE

### test for overall trend:

##  settlements year_ct habitat emmean     SE  df lower.CL upper.CL
##  Far            4.29 Slope    0.478 0.0218 203    0.435    0.521
##  Near           4.29 Slope    0.365 0.0169 203    0.331    0.398
##  Far            4.29 Wadi     0.460 0.0239 203    0.413    0.508
##  Near           4.29 Wadi     0.347 0.0365 203    0.275    0.419
## 
## Results are given on the inverse (not the response) scale. 
## Confidence level used: 0.95
##  contrast             estimate     SE  df t.ratio p.value
##  slope_far_minus_near   0.1135 0.0276 203   4.118  0.0001
##  far_slope_minus_wadi   0.0177 0.0323 203   0.547  0.5849
## 
## Note: contrasts are still on the inverse scale
##   settlements  year_ct habitat c.1 c.2
## 1         Far 4.287081   Slope   1   1
## 2        Near 4.287081   Slope  -1   0
## 3         Far 4.287081    Wadi   0  -1
## 4        Near 4.287081    Wadi   0   0